ORCID Profile
0000-0002-3994-6958
Current Organisation
The University of Newcastle
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Surfacewater Hydrology | Physical Geography and Environmental Geoscience | Water Resources Engineering | Palaeoclimatology | Quaternary Environments | Geomorphology and Regolith and Landscape Evolution | Climate Change Processes
ANZSRC Socio-Economic Objective (SEO)
Effects of Climate Change and Variability on Australia (excl. Social Impacts) | Atmospheric Processes and Dynamics | Natural Hazards in Fresh, Ground and Surface Water Environments | Global Effects of Climate Change and Variability (excl. Australia, New Zealand, Antarctica and the South Pacific) (excl. Social Impacts) | Natural Hazards in Urban and Industrial Environments | Expanding Knowledge in the Earth Sciences | Coastal and Estuarine Water Management | Water Services and Utilities |
Related Links
Publications
Farmers׳ perception of drought impacts, local adaptation and administrative mitigation measures in Maharashtra State, India
Publisher: Elsevier BV
Date: 12-2014
Explaining changes in rainfall–runoff relationships during and after Australia's Millennium Drought: a community perspective
Publisher: Copernicus GmbH
Date: 06-12-2022
DOI: 10.5194/HESS-26-6073-2022
Abstract: Abstract. The Millennium Drought lasted more than a decade and is notable for causing persistent shifts in the relationship between rainfall and runoff in many southeastern Australian catchments. Research to date has successfully characterised where and when shifts occurred and explored relationships with potential drivers, but a convincing physical explanation for observed changes in catchment behaviour is still lacking. Originating from a large multi-disciplinary workshop, this paper presents and evaluates a range of hypothesised process explanations of flow response to the Millennium Drought. The hypotheses consider climatic forcing, vegetation, soil moisture dynamics, groundwater, and anthropogenic influence. The hypotheses are assessed against evidence both temporally (e.g. why was the Millennium Drought different to previous droughts?) and spatially (e.g. why did rainfall–runoff relationships shift in some catchments but not in others?). Thus, the strength of this work is a large-scale assessment of hydrologic changes and potential drivers. Of 24 hypotheses, 3 are considered plausible, 10 are considered inconsistent with evidence, and 11 are in a category in between, whereby they are plausible yet with reservations (e.g. applicable in some catchments but not others). The results point to the unprecedented length of the drought as the primary climatic driver, paired with interrelated groundwater processes, including declines in groundwater storage, altered recharge associated with vadose zone expansion, and reduced connection between subsurface and surface water processes. Other causes include increased evaporative demand and harvesting of runoff by small private dams. Finally, we discuss the need for long-term field monitoring, particularly targeting internal catchment processes and subsurface dynamics. We recommend continued investment in the understanding of hydrological shifts, particularly given their relevance to water planning under climate variability and change.
Natural hazards in Australia: floods
Publisher: Springer Science and Business Media LLC
Date: 11-05-2016
Causes of the Widespread 2019–2020 Australian Bushfire Season
Publisher: American Geophysical Union (AGU)
Date: 11-2020
DOI: 10.1029/2020EF001671
An ice core derived 1013-year catchment-scale annual rainfall reconstruction in subtropical eastern Australia
Publisher: Copernicus GmbH
Date: 11-05-2016
DOI: 10.5194/HESS-20-1703-2016
Abstract: Abstract. Paleoclimate research indicates that the Australian instrumental climate record (∼ 100 years) does not cover the full range of hydroclimatic variability that is possible. To better understand the implications of this on catchment-scale water resources management, a 1013-year (1000–2012 common era (CE)) annual rainfall reconstruction was produced for the Williams River catchment in coastal eastern Australia. No high-resolution paleoclimate proxies are located in the region and so a teleconnection between summer sea salt deposition recorded in ice cores from East Antarctica and rainfall variability in eastern Australia was exploited to reconstruct the catchment-scale rainfall record. The reconstruction shows that significantly longer and more frequent wet and dry periods were experienced in the preinstrumental compared to the instrumental period. This suggests that existing drought and flood risk assessments underestimate the true risks due to the reliance on data and statistics obtained from only the instrumental record. This raises questions about the robustness of existing water security and flood protection measures and has serious implications for water resources management, infrastructure design and catchment planning. The method used in this proof of concept study is transferable and enables similar insights into the true risk of flood/drought to be gained for other paleoclimate proxy poor regions for which suitable remote teleconnected proxies exist. This will lead to improved understanding and ability to deal with the impacts of multi-decadal to centennial hydroclimatic variability.
On the uncertainties associated with using gridded rainfall data as a proxy for observed
Publisher: Copernicus GmbH
Date: 23-05-2012
DOI: 10.5194/HESS-16-1481-2012
Abstract: Abstract. Gridded rainfall datasets are used in many hydrological and climatological studies, in Australia and elsewhere, including for hydroclimatic forecasting, climate attribution studies and climate model performance assessments. The attraction of the spatial coverage provided by gridded data is clear, particularly in Australia where the spatial and temporal resolution of the rainfall gauge network is sparse. However, the question that must be asked is whether it is suitable to use gridded data as a proxy for observed point data, given that gridded data is inherently "smoothed" and may not necessarily capture the temporal and spatial variability of Australian rainfall which leads to hydroclimatic extremes (i.e. droughts, floods). This study investigates this question through a statistical analysis of three monthly gridded Australian rainfall datasets – the Bureau of Meteorology (BOM) dataset, the Australian Water Availability Project (AWAP) and the SILO dataset. The results of the monthly, seasonal and annual comparisons show that not only are the three gridded datasets different relative to each other, there are also marked differences between the gridded rainfall data and the rainfall observed at gauges within the corresponding grids – particularly for extremely wet or extremely dry conditions. Also important is that the differences observed appear to be non-systematic. To demonstrate the hydrological implications of using gridded data as a proxy for gauged data, a rainfall-runoff model is applied to one catchment in South Australia initially using gauged data as the source of rainfall input and then gridded rainfall data. The results indicate a markedly different runoff response associated with each of the different sources of rainfall data. It should be noted that this study does not seek to identify which gridded dataset is the "best" for Australia, as each gridded data source has its pros and cons, as does gauged data. Rather, the intention is to quantify differences between various gridded data sources and how they compare with gauged data so that these differences can be considered and accounted for in studies that utilise these gridded datasets. Ultimately, if key decisions are going to be based on the outputs of models that use gridded data, an estimate (or at least an understanding) of the uncertainties relating to the assumptions made in the development of gridded data and how that gridded data compares with reality should be made.
Evaluation of climate change impacts and adaptation strategies for maize cultivation in the Himalayan foothills of India
Publisher: IWA Publishing
Date: 08-04-2015
DOI: 10.2166/WCC.2015.070
Abstract: This study evaluates the impacts of climate change on rainfed maize (Zea mays) yield and evaluates different agro-adaptation measures to counteract its negative impacts at Sikkim, a Himalayan state of India. Future climate scenarios for the 10 years centered on 2025, 2055 and 2085 were obtained by downscaling the outputs of the HadCM3 General Circulation Model (GCM) under for A2 and B2 emission scenarios. HadCM3 was chosen after assessing the performance analysis of six GCMs for the study region. The daily maximum and minimum temperatures are projected to rise in the future and precipitation is projected to decrease (by 1.7 to 22.6% relative to the 1991–2000 baseline) depending on the time period and scenarios considered. The crop simulation model CERES-Maize was then used to simulate maize yield under future climate change for the future time windows. Simulation results show that climate change could reduce maize productivity by 10.7–18.2%, compared to baseline yield, under A2 and 6.4–12.4% under B2 scenarios. However, the results also indicate that the projected decline in maize yield could be offset by early planting of seeds, lowering the farm yard manure application rate, introducing supplementary irrigation and shifting to heat tolerant varieties of maize.
Reconstructing pre-instrumental streamflow in Eastern Australia using a water balance approach
Publisher: Elsevier BV
Date: 03-2018
Non–stationarity in annual maxima rainfall across Australia – implications for Intensity–Frequency–Duration (IFD) relationships
Publisher: Copernicus GmbH
Date: 30-03-2015
DOI: 10.5194/HESSD-12-3449-2015
Abstract: Abstract. Rainfall Intensity–Frequency–Duration (IFD) relationships are commonly required for the design and planning of water supply and management systems around the world. Currently IFD information is based on the "stationary climate assumption" – that weather at any point in time will vary randomly and that the underlying climate statistics (including both averages and extremes) will remain constant irrespective of the period of record. However, the validity of this assumption has been questioned over the last 15 years, particularly in Australia, following an improved understanding of the significant impact of climate variability and change occurring on interannual to multidecadal timescales. This paper provides evidence of non-stationarity in annual maxima rainfall timeseries using 96 daily rainfall stations and 66 sub-daily rainfall stations across Australia. Further, the effect of non-stationarity on the resulting IFD estimates are explored for three long-term sub-daily rainfall records (Brisbane, Sydney and Melbourne) utilising insights into multidecadal climate variability. It is demonstrated that IFD relationships may under- or over-estimate the design rainfall depending on the length and time period spanned by the rainfall data used to develop the IFD information. It is recommended that non-stationarity in annual maxima rainfall be explicitly considered and appropriately treated in the ongoing revisions of Engineers Australia's guide to estimating and utilising IFD information, "Australian Rainfall and Runoff", and that clear guidance needs to be provided on how to deal with the issue of non-stationarity of extreme events (irrespective of whether that non-stationarity is due to natural or anthropogenic climate change). The findings of our study also have important implications for other regions of the world that exhibit considerable hydroclimatic variability and where IFD information is based on relatively short data sets.
Future hydroclimatology of the Mekong River basin simulated using the high‐resolution Japan Meteorological Agency (JMA) AGCM
Publisher: Wiley
Date: 31-03-2008
DOI: 10.1002/HYP.6947
Bridging the gap between end user needs and science capability: decision making under uncertainty
Publisher: Inter-Research Science Center
Date: 02-09-2014
DOI: 10.3354/CR01243
2020s scenario analysis of nutrient load in the Mekong River Basin using a distributed hydrological model
Publisher: Elsevier BV
Date: 10-2009
DOI: 10.1016/J.SCITOTENV.2009.06.026
Abstract: A distributed hydrological model, YHyM, was integrated with the export coefficient concept and applied to simulate the nutrient load in the Mekong River Basin. In the validation period (1992-1999), Nash-Sutcliffe efficiency was 76.4% for discharge, 65.9% for total nitrogen, and 45.3% for total phosphorus at Khong Chiam. Using the model, scenario analysis was then performed for the 2020s taking into account major anthropogenic factors: climate change, population, land cover, fertilizer use, and industrial waste water. The results show that the load at Kompong Cham in 2020s is 6.3 x 10(4)tN a(-1) (+13.0% compared to 1990s) and 4.3 x 10(3)tP a(-1) (+24.7%). Overall, the noticeable nutrient sources are cropland in the middle region and urban load in the lower region. The installation of waste water treatment plants in urban areas possibly cut 60.6%N and 19.9%P of the estimated increase in the case without any treatment.
How did the 2012 drought affect rural livelihoods in vulnerable areas? Empirical evidence from India
Publisher: Elsevier BV
Date: 09-2015
From barriers to limits to climate change adaptation: path dependency and the speed of change
Publisher: Resilience Alliance, Inc.
Date: 2015
Advance care planning in patients with incurable cancer: study protocol for a randomised controlled trial
Publisher: BMJ
Date: 12-2016
Explaining changes in rainfall-runoff relationships during and after Australia's Millennium Drought: a community perspective
Publisher: Copernicus GmbH
Date: 20-04-2022
Abstract: Abstract. The Millennium Drought lasted more than a decade, and is notable for causing persistent shifts in the relationship between rainfall and runoff in many south-east Australian catchments. Research to date has successfully characterised where and when shifts occurred and explored relationships with potential drivers, but a convincing physical explanation for observed changes in catchment behaviour is still lacking. Originating from a large multi-disciplinary workshop, this paper presents a range of possible process explanations of flow response, and then evaluates these hypotheses against available evidence. The hypotheses consider climatic forcing, vegetation, soil moisture dynamics, groundwater, and anthropogenic influence. The hypotheses are assessed against evidence both temporally (eg. why was the Millennium Drought different to previous droughts?) and spatially (eg. why did rainfall-runoff relationships shift in some catchments but not in others?). The results point to the unprecedented length of the drought as the primary climatic driver, paired with interrelated groundwater processes, including: declines in groundwater storage, reduced recharge associated with vadose zone expansion, and reduced connection between subsurface and surface water processes. Other causes include increased evaporative demand and interception of runoff by small private dams. Finally, we discuss the need for long-term field monitoring, particularly targeting internal catchment processes and subsurface dynamics. We recommend continued investment in understanding of hydrological shifts, particularly given their relevance to water planning under climate variability and change.
Bridging the gap between researchers and decision‐makers
Publisher: Wiley
Date: 31-10-2014
Development and Evaluation of a Stochastic Daily Rainfall Model with Long Term Variability
Publisher: Copernicus GmbH
Date: 27-02-2017
DOI: 10.5194/HESS-2017-84
Abstract: Abstract. The primary objective of this study is to develop a stochastic rainfall generation model that can match not only the short resolution (daily) variability, but also the longer resolution (monthly to multiyear) variability of observed rainfall. This study has developed a Markov Chain (MC) model, which uses a two-state MC process with two parameters (wet-to-wet and dry-to-dry transition probabilities) to simulate rainfall occurrence and a Gamma distribution with two parameters (mean and standard deviation of wet day rainfall) to simulate wet day rainfall depths. Starting with the traditional MC-Gamma model with deterministic parameters, this study has developed and assessed four other variants of the MC-Gamma model with different parameterisations. The key finding is that if the parameters of the Gamma distribution are randomly s led from fitted distributions prior to simulating the rainfall for each year, the variability of rainfall depths at longer resolutions can be preserved, while the variability of wet periods (i.e. number of wet days and mean length of wet spell) can be preserved by decade-varied MC parameters. This is a straightforward enhancement to the traditional simplest MC model and is both objective and parsimonious.
Stratification response of soil water content during rainfall events under different rainfall patterns
Publisher: Wiley
Date: 19-08-2018
DOI: 10.1002/HYP.13250
Calibrating a hydrological model in a regional river of the Qinghai–Tibet plateau using river water width determined from high spatial resolution satellite images
Publisher: Elsevier BV
Date: 09-2018
A synoptic bridge linking sea salt aerosol concentrations in East Antarctic snowfall to Australian rainfall
Publisher: Springer Science and Business Media LLC
Date: 04-08-2022
DOI: 10.1038/S43247-022-00502-W
Abstract: Previous research has shown that aerosol sea salt concentrations (Southern Ocean wind proxy) preserved in the Law Dome ice core (East Antarctica) correlate significantly with subtropical eastern Australian rainfall. However, physical mechanisms underpinning this connection have not been established. Here we use synoptic typing to show that an atmospheric bridge links East Antarctica to subtropical eastern Australia. Increased ice core sea salt concentrations and wetter conditions in eastern Australia are associated with a regional, asymmetric contraction of the mid-latitude westerlies. Decreased ice core sea salt concentrations and drier eastern Australia conditions are associated with an equatorward shift in the mid-latitude westerlies, suggesting greater broad-scale control of eastern Australia climate by southern hemisphere variability than previously assumed. This relationship explains double the rainfall variance compared to El Niño-Southern Oscillation during late spring-summer, highlighting the importance of the Law Dome ice core record as a 2000-year proxy of eastern Australia rainfall variability.
Large floods in South East Queensland, Australia: Is it valid to assume they occur randomly?
Publisher: Informa UK Limited
Date: 02-01-2018
Mechanisms influencing non-stationarity in rainfall-runoff relationships in southeast Australia
Publisher: Elsevier BV
Date: 04-2019
Stochastic Generation of Future Hydroclimate Using Temperature as a Climate Change Covariate
Publisher: American Geophysical Union (AGU)
Date: 02-2021
DOI: 10.1029/2020WR027331
Abstract: It is now standard practice for water supply agencies to use stochastic models to generate synthetic hydroclimate sequences that preserve the key statistics contained in the observed/instrumental hydroclimate data (usually rainfall, potential evapotranspiration, and streamflow) for use as inputs when determining water security. However, this approach is only adequate for determining current and future water supply risks if nonstationarity in past and future climate is accounted for. In this study, we develop an approach for stochastically generating future seasonal (monthly to annual) hydroclimatic conditions at multiple sites for water supply security assessment that capitalizes on an Australia‐wide relationship between annual average daily maximum temperature and annual rain (and flow). This approach is practical as it (i) avoids the extra time and additional uncertainties introduced by downscaling and bias correction of climate model produced rainfall information and (ii) takes advantage of the fact that climate model projections for temperature change are more realistic than climate model projections for rainfall. The approach is applied to a case study for catchments supplying Sydney, Australia's largest city. Two future scenarios were evaluated, 1 and 2°C warming over the next 50 years. Large reductions in streamflow were simulated, particularly for the 2°C scenario, resulting in major impacts on water security in the absence of any intervention. This is consistent with recent warming since 1990 being associated with more than a 40% decrease in average annual streamflow when compared with the average annual streamflow over the ∼110 years historical record.
Australian rainfall variability—Why is the eastern seaboard of Australia different to the rest of Australia and also internally inhomogeneous
Publisher: Wiley
Date: 14-04-2021
DOI: 10.1002/JOC.7116
Abstract: The Eastern Seaboard of Australia (ESA) has been identified as being different to the rest of Australia in terms of rainfall patterns. However, rainfall patterns within the ESA itself are not well understood. This study identifies Australian rainfall districts that exhibit similar (and different) temporal variation, with the primary aim being to determine if the ESA can be considered a homogenous region with respect to rainfall. The results (a) confirm that the ESA is different to the rest of Australia and (b) show that the ESA is not homogenous and that East Coast Lows (ECLs) are linked to this inhomogeneity. For winter (JJA) three separate isions within the ESA are identified and at least two clear isions are identified in other seasons. ECL sub‐types contribute to this inhomogeneity because each ECL sub‐type is associated with different spatio‐temporal rainfall patterns across the ESA. This is an important insight for natural resources management and emergency services within the heavily populated ESA because it demonstrates that existing climate related risks are different across the ESA. Further, the way climate risks change in the future is also likely to be inconsistent across the ESA. Future climate related risks will depend on how ECL behaviour (e.g., intensity, frequency, location, duration, path and geographical extent) changes. This reinforces the need for locally relevant and practically useful climate science information and adaptation strategies—as opposed to the State‐ or country‐wide information and adaptation approaches that are commonly used.
An annually dated Interdecadal Pacific Oscillation reconstruction spanning the last two millennia
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-6218
Abstract: & & The Interdecadal Pacific Oscillation (IPO) is a nominally 15-30 year climate mode that has been identified through analysis of tropical and extratropical Pacific sea surface temperatures over the past 150 years. It is still unclear whether the IPO is a true oscillation or whether it is simply the low frequency response of the climate system to forcing (natural and potentially anthropogenic), principally ENSO. Regardless of this, the IPO as it is currently known has clear climate impacts, one ex le being hydroclimate variability in Australia. In positive phases of the IPO, drought risk is heightened due to a reduction in the likelihood of large, recharging La Nina-derived rainfall events. Conversely, in IPO negative phases, flood risk in Australia is greatly increased due to an increased likelihood of such rain events.& & & & Previous work derived a 1000 year, accurately dated reconstruction of the IPO from multiple palaeoclimate archives from the Law Dome ice core in East Antarctica. This reconstruction provided a long-term reconstruction with which to assess the true risk of drought- and flood-prone epochs in Australia. Subsequently, an entirely independent reconstruction of the IPO was developed using SE Asian tree rings by Buckley et al. in 2019, also spanning most of the last millennium. The fidelity the two reconstructions display with respect to the instrumental IPO record and with each other suggests both are faithfully representing IPO variability. Here we present an IPO reconstruction that doubles the temporal span of existing reconstructions to cover the last 2000 years using newly analysed and dated material from the Law Dome ice core. This new, longer reconstruction identifies important features of Pacific decadal variability that have significant implications for understanding hydroclimate epochs across not only Australasia, but the Pacific region as a whole.& &
Physical and non-physical factors associated with water consumption at the household level in a region using multiple water sources
Publisher: Elsevier BV
Date: 10-2021
Supplementary material to "Comparison of published palaeoclimate records suitable for reconstructing annual to sub-decadal hydroclimatic variability in eastern Australia: implications for w
Publisher: Copernicus GmbH
Date: 30-06-2020
Comparing the performance of drought indicators in Australia from 1900 to 2018
Publisher: Wiley
Date: 12-08-2021
DOI: 10.1002/JOC.6737
Water resource management in a variable and changing climate: hypothetical case study to explore decision making under uncertainty
Publisher: IWA Publishing
Date: 06-11-2015
DOI: 10.2166/WCC.2015.040
Abstract: This paper investigates what information water resource managers think they need to make decisions on climate change adaptation. This is achieved through a hypothetical case study where participants, all actual water resource managers or in research, practitioner or administration roles linked to Australian water resources management, were given theoretical future climate scenarios and asked to make decisions based on the available information. The case study provided useful insights into why there is little evidence of effective climate change adaptation being implemented despite significant advances in climate impacts and adaptation science over the last decade. It was found that in order to bridge the gap between climate change adaptation recommendations and successful implementation at practitioner level there is a demand for: improved translation, communication and packaging of existing climate science information into sector- and location-specific impacts (e.g. hydrological interpretation of climate model rainfall projections and the associated uncertainties) attribution of historical and future hydroclimatic changes (e.g. not just what has happened or is going to happen but why and the confidence and likelihoods surrounding that) quantification of costs and benefits of any decision and understanding of the social, political, and environmental contexts and level of acceptance associated with any decision.
Natural hazards in Australia: sea level and coastal extremes
Publisher: Springer Science and Business Media LLC
Date: 24-03-2016
Large‐scale ocean‐atmospheric processes and seasonal rainfall variability in South Australia: potential for improving seasonal hydroclimatic forecasts
Publisher: Wiley
Date: 22-03-2017
DOI: 10.1002/JOC.5043
Links between the Big Dry in Australia and hemispheric multi-decadal climate variability – implications for water resource management
Publisher: Copernicus GmbH
Date: 18-06-2014
DOI: 10.5194/HESS-18-2235-2014
Abstract: Abstract. Southeast Australia (SEA) experienced a protracted drought during the mid-1990s until early 2010 (known as the Big Dry or Millennium Drought) that resulted in serious environmental, social and economic effects. This paper analyses a range of historical climate data sets to place the recent drought into context in terms of Southern Hemisphere inter-annual to multi-decadal hydroclimatic variability. The findings indicate that the recent Big Dry in SEA is in fact linked to the widespread Southern Hemisphere climate shift towards drier conditions that began in the mid-1970s. However, it is shown that this link is masked because the large-scale climate drivers responsible for drying in other regions of the mid-latitudes since the mid-1970s did not have the same effect on SEA during the mid- to late 1980s and early 1990s. More specifically, smaller-scale synoptic processes resulted in elevated autumn and winter rainfall (a crucial period for SEA hydrology) during the mid- to late 1980s and early 1990s, which punctuated the longer-term drying. From the mid-1990s to 2010 the frequency of the synoptic processes associated with elevated autumn/winter rainfall decreased, resulting in a return to drier than average conditions and the onset of the Big Dry. The findings presented in this paper have marked implications for water management and climate attribution studies in SEA, in particular for understanding and dealing with "baseline" (i.e. current) hydroclimatic risks.
Supplementary material to "An ice core derived 1013-year catchment scale annual rainfall reconstruction in subtropical eastern Australia"
Publisher: Copernicus GmbH
Date: 03-12-2015
Synchronicity of historical dry spells in the Southern Hemisphere
Publisher: Copernicus GmbH
Date: 18-06-2014
DOI: 10.5194/HESS-18-2257-2014
Abstract: Abstract. A shift in climate occurred during the mid-1970s that affected the hydroclimate of the Southern Hemisphere resulting in drying trends across continental regions including Australia, New Zealand and southern and western Africa. There is also anecdotal evidence of other periods of climatic synchronicity in the Southern Hemisphere (e.g., the 1920s and 1940s), indicating that the mid-1970s event may not be anomalous. This paper identifies periods within the last ~120 years using statistical analysis where dry spells (in terms of annual to multi-decadal rainfall deficiencies) have coincided across the continental Southern Hemisphere in order to characterize temporal consistency. It is shown that synchronicity of dry spells is (a) most likely common over the last 120 years and (b) associated with changes in the large-scale climate modes of the Pacific, Indian and Southern Oceans. Importantly, the findings presented in this paper have marked implications for drought management and drought forecasting studies in the Southern Hemisphere.
Local perceptions of and adaptation to climate variability and change: the case of shrimp farming communities in the coastal region of Bangladesh
Publisher: Springer Science and Business Media LLC
Date: 21-07-2015
Drought-related stress among farmers: findings from the Australian Rural Mental Health Study.
Publisher: AMPCo
Date: 30-07-2018
DOI: 10.5694/MJA17.01200
Abstract: To investigate general and drought-related stress experienced by farmers at both the personal and community levels, and whether socio-demographic and community factors influence this stress. Multivariate analysis of data from the Australian Rural Mental Health Study (ARMHS), a longitudinal cohort study (2007-2013). Non-metropolitan New South Wales. Subset of 664 ARMHS participants (at baseline) who identified as living or working on a farm. Personal drought-related stress (PDS), community drought-related stress (CDS), and general psychological distress (K10 score). Farmers who were under 35, both lived and worked on a farm, experienced greater financial hardship, and were in outer regional, remote or very remote NSW reported PDS particularly frequently. Of these factors, only being under 35 and increased remoteness were associated with higher incidence of CDS. Mild wet weather during the prior 12 months reduced PDS and CDS but increased general distress. Moderate or extreme wet weather did not affect PDS or general distress, but moderate wet weather was associated with increased CDS. Drought-related stress and general psychological distress were influenced by different socio-demographic and community factors. Farmers in NSW experience significant stress about the effects of drought on themselves, their families, and their communities. Farmers who are younger, live and work on a farm, experience financial hardship, or are isolated are at particular risk of drought-related stress. Medical practitioners who provide assistance to farmers and farming communities can contribute to initiatives that relieve stress about drought.
A linked surface water-groundwater modelling approach to more realistically simulate rainfall-runoff non-stationarity in semi-arid regions
Publisher: Elsevier BV
Date: 08-2019
A Spatial Data-Driven Approach for Mineral Prospectivity Mapping
Publisher: MDPI AG
Date: 18-08-2023
DOI: 10.3390/RS15164074
Abstract: Mineral prospectivity mapping is a crucial technique for discovering new economic mineral deposits. However, detailed knowledge-based geological exploration and interpretations generally involve significant costs, time, and human resources. In this study, an ensemble machine learning approach was tested using geoscience datasets to map Cu-Au and Pb-Zn mineral prospectivity in the Cobar Basin, NSW, Australia. The input datasets (magnetic, gravity, faults, electromagnetic, and magnetotelluric data layers) were chosen by considering their association with Cu-Au and Pb-Zn mineralization patterns. Three machine learning algorithms, namely random forest (RF), support vector machine (SVM), and maximum-likelihood (MaxL) classification, were applied to the input data. The results of the three algorithms were ensembled to produce Cu-Au and Pb-Zn prospectivity maps over the Cobar Basin with improved classification accuracy. The findings demonstrate good agreement with known mineral occurrence points and existing mineral prospectivity maps developed using the weights-of-evidence (WofE) method. The ability to capture training points accurately and the simplicity of the proposed approach make it advantageous over complex mineral prospectivity mapping methods, to serve as a preliminary evaluation technique. The methodology can be modified with different datasets and algorithms, facilitating the investigations of mineral prospectivity in other regions and providing guidance for more detailed, high-resolution geological investigations.
Estimating potential evapotranspiration using Shuttleworth–Wallace model and NOAA-AVHRR NDVI data to feed a distributed hydrological model over the Mekong River basin
Publisher: Elsevier BV
Date: 07-2006
Multi-decadal variability of drought risk, eastern Australia
Publisher: Wiley
Date: 23-07-2004
DOI: 10.1002/HYP.1460
Using paleoclimate reconstructions to analyse hydrological epochs associated with Pacific Decadal Variability
Publisher: Copernicus GmbH
Date: 23-04-2201
Abstract: Abstract. The duration of dry or wet hydrological epochs (run lengths) associated with positive or negative Inter-decadal Pacific Oscillation (IPO) or Pacific Decadal Oscillation (PDO) phases, termed Pacific Decadal Variability (PDV), is an essential statistical property for understanding, assessing and managing hydroclimatic risk. Numerous IPO and PDO paleoclimate reconstructions provide a valuable opportunity to study the statistical signatures of PDV, including run lengths. However, disparities exist between these reconstructions making it problematic to determine which reconstruction(s) to use to investigate pre-instrumental PDV and run length. Variability and persistence on centennial scales are also present in some millennium long reconstructions, making consistent run length extraction difficult. Thus, a robust method to extract meaningful and consistent run lengths from multiple reconstructions is required. In this study, a dynamic threshold framework to account for centennial trends in PDV reconstructions is proposed. The dynamic threshold framework is shown to extract meaningful run length information from multiple reconstructions. Two hydrologically important aspects of the statistical signatures associated with the PDV are explored: (i) whether persistence (i.e. run lengths) during positive epochs is different to persistence during negative epochs and (ii) whether the reconstructed run lengths are stationary during the past millennium. Results suggest that there is no significant difference between run lengths in positive and negative phases of PDV and that it is more likely than not that the PDV run length has been non-stationary in the past millennium. This raises concerns about whether variability seen in the instrumental record (the last ~ 100 years), or even in the shorter 300–400 year paleoclimate reconstructions, is representative of the full range of variability.
On the identification of ENSO-induced rainfall and runoff variability: a comparison of methods and indices
Publisher: Informa UK Limited
Date: 10-2001
A New Approach to Stochastically Generating Six-Monthly Rainfall Sequences Based on Empirical Mode Decomposition
Publisher: American Meteorological Society
Date: 12-2008
DOI: 10.1175/2008JHM991.1
Abstract: This paper introduces a new approach to stochastically generating rainfall sequences that can take into account natural climate phenomena, such as the El Niño–Southern Oscillation and the interdecadal Pacific oscillation. The approach is also amenable to modeling projected affects of anthropogenic climate change. The method uses a relatively new technique, empirical mode decomposition (EMD), to decompose a historical rainfall series into several independent time series that have different average periods and litudes. These time series are then recombined to form an intradecadal time series and an interdecadal time series. After separate stochastic generation of these two series, because they are independent, they can be recombined by summation to form a replicate equivalent to the historical data. The approach was applied to generate 6-monthly rainfall totals for six rainfall stations located near Canberra, Australia. The cross correlations were preserved by carrying out the stochastic analysis using the Matalas multisite model. The results were compared with those obtained using a traditional autoregressive lag-one [AR(1)], and it was found that the new EMD stochastic model performed satisfactorily. The new approach is able to realistically reproduce multiyear–multidecadal dry and wet epochs that are characteristic of Australia’s climate and are not satisfactorily modeled using traditional stochastic rainfall generation methods. The method has two advantages over the traditional AR(1) approach, namely, that it can simulate nonstationarity characteristics in the historical time series, and it is easy to alter the decomposed time series components to examine the impact of anthropogenic climate change.
Synoptic climatology of southern Indian Ocean and paleoclimate proxy interpretation
Publisher: Copernicus GmbH
Date: 03-03-2021
DOI: 10.5194/EGUSPHERE-EGU21-3756
Abstract: & & Weather systems in the southern Indian Ocean drive synoptic-scale precipitation, temperature and wind variability in East Antarctica, sub-Antarctic islands and southern Australia. & Over seasonal to decadal timescales, the mean condition associated with combinations of these synoptic weather patterns (e.g., extratropical cyclones, fronts and regions of high pressure) is often referred to as variability in the westerly wind belt or the Southern Annular Mode (SAM). The westerly wind belt is generally considered to be zonally symmetric around Antarctica however, on a daily timescale this is not the case. To capture the daily variability of regional weather systems, we used synoptic typing (Self-Organising Maps) to group weather patterns based on similar features, which are often lost when using monthly or seasonal mean fields. We identified nine key regional weather types based on anomaly pattern and strength. These include four meridional nodes, three mixed nodes, one zonal node and one transitional node. The meridional nodes are favourable for transporting warm, moist air masses to the subantarctic and Antarctic region, and are associated with increased precipitation and temperature where the systems interact with the Antarctic coastline. & These nodes have limited association with the SAM, especially during austral spring.& In contrast, the zonal and mixed nodes were strongly correlated with the SAM however, the regional synoptic representation of SAM positive conditions is not zonally symmetric and is represented by three separate nodes.& These different types of SAM positive conditions mean that the commonly used hemispheric Marshall index often fails to capture the regional variability in surface weather conditions in the southern Indian Ocean. Our results show the importance of considering different synoptic set ups of SAM conditions, particularly SAM positive, and identify conditions that are potentially missed by SAM variability (e.g., extreme precipitation events). Our results are particularly important to consider when interpreting SAM or westerly wind belt reconstructions in the study region (from ice cores, tree rings, or lake sediments). & Here we present a case study using the synoptic typing results to enhance our understanding of the Law Dome (East Antarctica) ice core record, focussing on links to large scale modes of climate variability and Australian hydroclimate.& These results enhance the usefulness of ice core proxies in coastal East Antarctica and assist with determining where and how it is appropriate to use coastal East Antarctic ice core records for reconstructions of large scale modes of climate variability (e.g. SAM and ENSO) and remote hydroclimate conditions.& &
Steps toward “useful” hydroclimatic scenarios for water resource management in the Murray‐Darling Basin
Publisher: American Geophysical Union (AGU)
Date: 16-06-2011
DOI: 10.1029/2010WR009803
Nature and causes of protracted droughts in southeast Australia: Comparison between the Federation, WWII, and Big Dry droughts
Publisher: American Geophysical Union (AGU)
Date: 11-2009
DOI: 10.1029/2009GL041067
Synchronicity of historical dry spells in the Southern Hemisphere
Publisher: Copernicus GmbH
Date: 02-12-2013
DOI: 10.5194/HESSD-10-14571-2013
Abstract: Abstract. A shift in climate occurred during the mid-1970s that affected the hydroclimate of the Southern Hemisphere resulting in drying trends across continental regions including Australia, New Zealand and southern and western Africa. There is also anecdotal evidence of other periods of climatic synchronicity in the Southern Hemisphere (e.g. the 1920s and 1940s), indicating that the mid 1970s event may not be anomalous. This paper identifies periods within the last ~120 yr using statistical analysis where dry spells (in terms of annual to multi-decadal rainfall deficiencies) have coincided across the continental Southern Hemisphere in order to characterize temporal consistency. It is shown that synchronicity of dry spells is (a) most likely common over the last 120 yr and (b) associated with changes in the large-scale climate modes of the Pacific, Indian and Southern Oceans. Importantly, the findings presented in this paper have marked implications for drought management and drought forecasting studies in the Southern Hemisphere.
Towards understanding hydroclimatic change in Victoria, Australia – preliminary insights into the "Big Dry"
Publisher: Copernicus GmbH
Date: 08-03-2010
Abstract: Abstract. Since the mid-1990s the majority of Victoria, Australia, has experienced severe drought conditions (i.e. the "Big Dry") characterized by streamflow that is the lowest in approximately 80 years of record. While decreases in annual and seasonal rainfall totals have also been observed, this alone does not seem to explain the observed reduction in flow. In this study, we investigate the large-scale climate drivers for Victoria and demonstrate how these modulate the regional scale synoptic patterns, which in turn alter the way seasonal rainfall totals are compiled and the amount of runoff per unit rainfall that is produced. The hydrological implications are significant and illustrate the need for robust hydrological modelling, that takes into account insights into physical mechanisms that drive regional hydroclimatology, in order to properly understand and quantify the impacts of climate change (natural and/or anthropogenic) on water resources.
Relating BTOPMC model parameters to physical features of MOPEX basins
Publisher: Elsevier BV
Date: 03-2006
Estimation of Soil Erosion and Sediment Yield During Individual Rainstorms at Catchment Scale
Publisher: Springer Science and Business Media LLC
Date: 24-09-2008
Robust optimisation of urban drought security for an uncertain climate
Publisher: Wiley
Date: 31-10-2015
Large‐scale ocean‐atmospheric processes and seasonal rainfall variability in South Australia: accounting for non‐linearity and establishing the hierarchy of influence
Publisher: Wiley
Date: 10-04-2017
DOI: 10.1002/JOC.5074
Drought and the future of rural communities: Opportunities and challenges for climate change adaptation in regional Victoria, Australia
Publisher: Elsevier BV
Date: 10-2013
Influence of ENSO , ENSO Modoki, and the IPO on tropical cyclogenesis: a spatial analysis of the southwest Pacific region
Publisher: Wiley
Date: 10-04-2017
DOI: 10.1002/JOC.5070
Robust optimization to secure urban bulk water supply against extreme drought and uncertain climate change
Publisher: Elsevier BV
Date: 07-2015
Pacific decadal variability over the last 2000 years and implications for climatic risk
Publisher: Springer Science and Business Media LLC
Date: 17-02-2022
DOI: 10.1038/S43247-022-00359-Z
Abstract: The Interdecadal Pacific Oscillation, an index which defines decadal climate variability throughout the Pacific, is generally assumed to have positive and negative phases that each last 20-30 years. Here we present a 2000-year reconstruction of the Interdecadal Pacific Oscillation, obtained using information preserved in Antarctic ice cores, that shows negative phases are short (7 ± 5 years) and infrequent (occurring 10% of the time) departures from a predominantly neutral-positive state that lasts decades (61 ± 56 years). These findings suggest that Pacific Basin climate risk is poorly characterised due to over-representation of negative phases in post-1900 observations. We demonstrate the implications of this for eastern Australia, where drought risk is elevated during neutral-positive phases, and highlight the need for a re-evaluation of climate risk for all locations affected by the Interdecadal Pacific Oscillation. The initiation and future frequency of negative phases should also be a research priority given their prevalence in more recent centuries.
Comparison of published palaeoclimate records suitable for reconstructing annual to sub-decadal hydroclimatic variability in eastern Australia: implications for water resource management and planning
Publisher: Copernicus GmbH
Date: 29-11-2020
DOI: 10.5194/HESS-24-5699-2020
Abstract: Abstract. Knowledge of past, current, and future hydroclimatic risk is of great importance. However, like many other countries, Australia's observed hydroclimate records are at best only ∼ 120 years long (i.e. from ∼ 1900 to the present) but are typically less than ∼ 50 years long. Therefore, recent research has focused on developing longer hydroclimate records based on palaeoclimate information from a variety of different sources. Here we review and compare the insights emerging from 11 published palaeoclimate records that are relevant for annual to sub-decadal hydroclimatic variability in eastern Australia over the last ∼ 1000 years. The sources of palaeoclimate information include ice cores, tree rings, cave deposits, and lake sediment deposits. The published palaeoclimate information was then analysed to determine when (and where) there was agreement (or uncertainty) about the timing of wet and dry epochs in the pre-instrumental period (1000–1899). The occurrence, frequency, duration, and spatial extent of pre-instrumental wet and dry epochs was then compared to wet and dry epochs since 1900. The results show that instrumental records (∼ 1900–present) underestimate (or at least misrepresent) the full range of rainfall variability that has occurred, and is possible, in eastern Australia. Even more disturbing is the suggestion, based on insights from the published palaeoclimate data analysed, that 71 % of the pre-instrumental period appears to have no equivalent in the instrumental period. This implies that the majority of the past 1000 years was unlike anything encountered in the period that informs water infrastructure, planning, and policy in Australia. A case study, using a typical water storage reservoir in eastern Australia, demonstrates that current water resource infrastructure and management strategies would not cope under the range of pre-instrumental conditions that this study suggests has occurred. When coupled with projected impacts of climate change and growing demands, these results highlight some major challenges for water resource management and infrastructure. Though our case study location is eastern Australia, these challenges, and the limitations associated with current methods that depend on instrumental records that are too short to realistically characterise interannual to multi-decadal variability, also apply globally.
A paleoclimate rainfall reconstruction in the Murray‐Darling Basin (MDB), Australia: 2. Assessing hydroclimatic risk using paleoclimate records of wet and dry epochs
Publisher: American Geophysical Union (AGU)
Date: 10-2015
DOI: 10.1002/2015WR017059
Understanding hydroclimate processes in the Murray-Darling Basin for natural resources management
Publisher: Copernicus GmbH
Date: 12-07-2012
DOI: 10.5194/HESS-16-2049-2012
Abstract: Abstract. Isolating the causes of extreme variations or changes in the hydroclimate is difficult due to the complexities of the driving mechanisms, but it is crucial for effective natural resource management. In Australia's Murray-Darling Basin (MDB), ocean-atmosphere processes causing hydroclimatic variations occur on time scales from days to centuries, all are important, and none are likely to act in isolation. Instead, interactions between all hydroclimatic drivers, on multiple time scales, are likely to have caused the variations observed in MDB instrumental records. A simplified framework is presented to assist natural resource managers in identifying the potential causes of hydroclimatic anomalies. The framework condenses an event into its fundamental elements, including its spatial and temporal signal and small-scale evolution. The climatic processes that are potentially responsible are then examined to determine possible causes. The framework was applied to a period of prolonged and severe dry conditions occurring in the southern MDB from 1997–2010, providing insights into possible causal mechanisms that are consistent with recent studies. The framework also assists in identifying uncertainties and gaps in our understanding that need to be addressed.
A paleoclimate rainfall reconstruction in the M urray‐D arling B asin (MDB ), A ustralia: 1. Evaluation of different paleoclimate archives, rainfall n
Publisher: American Geophysical Union (AGU)
Date: 10-2015
DOI: 10.1002/2015WR017058
Regime shifts in annual maximum rainfall across Australia – implications for intensity–frequency–duration (IFD) relationships
Publisher: Copernicus GmbH
Date: 03-12-2015
DOI: 10.5194/HESS-19-4735-2015
Abstract: Abstract. Rainfall intensity–frequency–duration (IFD) relationships are commonly required for the design and planning of water supply and management systems around the world. Currently, IFD information is based on the "stationary climate assumption" that weather at any point in time will vary randomly and that the underlying climate statistics (including both averages and extremes) will remain constant irrespective of the period of record. However, the validity of this assumption has been questioned over the last 15 years, particularly in Australia, following an improved understanding of the significant impact of climate variability and change occurring on interannual to multidecadal timescales. This paper provides evidence of regime shifts in annual maximum rainfall time series (between 1913–2010) using 96 daily rainfall stations and 66 sub-daily rainfall stations across Australia. Furthermore, the effect of these regime shifts on the resulting IFD estimates are explored for three long-term (1913–2010) sub-daily rainfall records (Brisbane, Sydney, and Melbourne) utilizing insights into multidecadal climate variability. It is demonstrated that IFD relationships may under- or over-estimate the design rainfall depending on the length and time period spanned by the rainfall data used to develop the IFD information. It is recommended that regime shifts in annual maximum rainfall be explicitly considered and appropriately treated in the ongoing revisions of the Engineers Australia guide to estimating and utilizing IFD information, Australian Rainfall and Runoff (ARR), and that clear guidance needs to be provided on how to deal with the issue of regime shifts in extreme events (irrespective of whether this is due to natural or anthropogenic climate change). The findings of our study also have important implications for other regions of the world that exhibit considerable hydroclimatic variability and where IFD information is based on relatively short data sets.
Quantifying Drought Risk in a Nonstationary Climate
Publisher: American Meteorological Society
Date: 08-2010
Abstract: Water management in Australia has traditionally been carried out on the assumption that the historical record of rainfall, evaporation, streamflow, and recharge is representative of current and future climatic conditions. However, in many circumstances, this does not adequately address the potential risks to supply security for towns, industry, irrigators, and the environment. This is because the Australian climate varies markedly due to natural cycles that operate over periods of several years to several decades. There is also serious concern about how anthropogenic climate change may exacerbate drought risk in the future. In this paper, the frequency and severity of droughts are analyzed during a range of “climate states” (e.g., different phases of the Pacific, Indian, and/or Southern Oceans) to demonstrate that drought risk varies markedly over interannual through to multidecadal time scales. Importantly, by accounting for climate variability and change on multitemporal scales (e.g., interdecadal, multidecadal, and the palaeo scale), it is demonstrated that the risk of failure of current drought management practices may be better assessed and more robust climate adaptation responses developed.
An ice core derived 1013-year catchment scale annual rainfall reconstruction in subtropical eastern Australia
Publisher: Copernicus GmbH
Date: 03-12-2015
DOI: 10.5194/HESSD-12-12483-2015
Abstract: Abstract. Paleoclimate research indicates that the instrumental climate record (~100 years in Australia) does not cover the full range of hydroclimatic variability possible. To better understand the implications of this for catchment-scale water resources management, an annual rainfall reconstruction is produced for the Williams River catchment in coastal eastern Australia. No high resolution palaeoclimate proxies are located in the region and so a teleconnection between summer sea salt deposition recorded in ice cores from East Antarctica and rainfall variability in eastern Australia was exploited to reconstruct 1013 years of rainfall (AD 1000–2012). The reconstruction shows that significantly longer and more frequent wet and dry periods were experienced in the preinstrumental compared to the instrumental period. This suggests that existing drought and flood risk assessments underestimate the true risks due to the reliance on data and statistics obtained from only the instrumental record. This raises questions about the robustness of existing water security and flood protection measures and has serious implications for water resources management, infrastructure design, and catchment planning. The method used in this proof of concept study is transferable and enables similar insights into the true risk of flood/drought to be gained for other locations that are teleconnected to East Antarctica. This will lead to improved understanding and ability to deal with the impacts of multidecadal to centennial hydroclimatic variability.
An intercomparison of tropical cyclone best-track products for the southwest Pacific
Publisher: Copernicus GmbH
Date: 16-06-2016
DOI: 10.5194/NHESS-16-1431-2016
Abstract: Abstract. Recent efforts to understand tropical cyclone (TC) activity in the southwest Pacific (SWP) have led to the development of numerous TC databases. The methods used to compile each database vary and are based on data from different meteorological centres, standalone TC databases and archived synoptic charts. Therefore the aims of this study are to (i) provide a spatio-temporal comparison of three TC best-track (BT) databases and explore any differences between them (and any associated implications) and (ii) investigate whether there are any spatial, temporal or statistical differences between pre-satellite (1945–1969), post-satellite (1970–2011) and post-geostationary satellite (1982–2011) era TC data given the changing observational technologies with time. To achieve this, we compare three best-track TC databases for the SWP region (0–35° S, 135° E–120° W) from 1945 to 2011: the Joint Typhoon Warning Center (JTWC), the International Best Track Archive for Climate Stewardship (IBTrACS) and the Southwest Pacific Enhanced Archive of Tropical Cyclones (SPEArTC). The results of this study suggest that SPEArTC is the most complete repository of TCs for the SWP region. In particular, we show that the SPEArTC database includes a number of additional TCs, not included in either the JTWC or IBTrACS database. These SPEArTC events do occur under environmental conditions conducive to tropical cyclogenesis (TC genesis), including anomalously negative 700 hPa vorticity (VORT), anomalously negative vertical shear of zonal winds (VSZW), anomalously negative 700 hPa geopotential height (GPH), cyclonic (absolute) 700 hPa winds and low values of absolute vertical wind shear (EVWS). Further, while changes in observational technologies from 1945 have undoubtedly improved our ability to detect and monitor TCs, we show that the number of TCs detected prior to the satellite era (1945–1969) are not statistically different to those in the post-satellite era (post-1970). Although data from pre-satellite and pre-geostationary satellite periods are currently inadequate for investigating TC intensity, this study suggests that SPEArTC data (from 1945) may be used to investigate long-term variability of TC counts and TC genesis locations.
Supplementary material to "An intercomparison of tropical cyclone best-track products for the Southwest Pacific"
Publisher: Copernicus GmbH
Date: 19-02-2016
Climate Change and Water Resources
Publisher: CRC Press
Date: 22-05-2014
DOI: 10.1201/B16969
Multi‐decadal variability of flood risk
Publisher: American Geophysical Union (AGU)
Date: 2003
DOI: 10.1029/2002GL015992
Comment on “Drought variability in the eastern Australia and New Zealand summer drought atlas (ANZDA, CE 1500-2012) modulated by the Interdecadal Pacific Oscillation” by Palmer et al., 2015, doi: 10.1088/1748-9326/10/12/124002.
Publisher: IOP Publishing
Date: 30-05-2017
Interdecadal Pacific variability and eastern Australian megadroughts over the last millennium
Publisher: American Geophysical Union (AGU)
Date: 05-01-2015
DOI: 10.1002/2014GL062447
Using paleoclimate reconstructions to analyse hydrological epochs associated with Pacific decadal variability
Publisher: Copernicus GmbH
Date: 10-12-2018
DOI: 10.5194/HESS-22-6399-2018
Abstract: Abstract. The duration of dry or wet hydrological epochs (run lengths) associated with positive or negative Inter-decadal Pacific Oscillation (IPO) or Pacific Decadal Oscillation (PDO) phases, termed Pacific decadal variability (PDV), is an essential statistical property for understanding, assessing and managing hydroclimatic risk. Numerous IPO and PDO paleoclimate reconstructions provide a valuable opportunity to study the statistical signatures of PDV, including run lengths. However, disparities exist between these reconstructions, making it problematic to determine which reconstruction(s) to use to investigate pre-instrumental PDV and run length. Variability and persistence on centennial scales are also present in some millennium-long reconstructions, making consistent run length extraction difficult. Thus, a robust method to extract meaningful and consistent run lengths from multiple reconstructions is required. In this study, a dynamic threshold framework to account for centennial trends in PDV reconstructions is proposed. The dynamic threshold framework is shown to extract meaningful run length information from multiple reconstructions. Two hydrologically important aspects of the statistical signatures associated with the PDV are explored: (i) whether persistence (i.e. run lengths) during positive epochs is different to persistence during negative epochs and (ii) whether the reconstructed run lengths have been stationary during the past millennium. Results suggest that there is no significant difference between run lengths in positive and negative phases of PDV and that it is more likely than not that the PDV run length has been non-stationary in the past millennium. This raises concerns about whether variability seen in the instrumental record (the last ∼100 years), or even in the shorter 300–400-year paleoclimate reconstructions, is representative of the full range of variability.
Multidecadal variability of rainfall and streamflow: Eastern Australia
Publisher: American Geophysical Union (AGU)
Date: 10-2004
DOI: 10.1029/2004WR003234
Concerns about climate change among rural residents in Australia
Publisher: Elsevier BV
Date: 04-2020
Perceptions, impacts and adaptation of tropical cyclones in the Southwest Pacific: an urban perspective from Fiji, Vanuatu and Tonga
Publisher: Copernicus GmbH
Date: 26-11-2015
DOI: 10.5194/NHESSD-3-7135-2015
Abstract: Abstract. To better understand perceptions, impacts and adaptation strategies related to tropical cyclones (TCs) in urban environments of the Southwest Pacific (SWP), a survey (with 130 participants) was conducted across three island nations Fiji, Vanuatu and Tonga. The key aims of this study include: (i) understanding local perceptions of TC activity, (ii) investigating physical impacts of TC activity, and (iii) uncovering adaptation strategies used to offset the impacts of TCs. It was found that current methods of adaptation generally occur at the local level immediately prior to a TC event (preparation of property, gathering of food, setting up of community centres). This method of adaptation appears to be effective, however higher level adaptation measures (such as the development of building codes as developed in Fiji) may reduce vulnerability further. The survey responses also highlight that there is significant scope to provide education programs specifically aimed at improving the understanding of weather related aspects of TCs. Finally, we investigate the potential to merge ecological traditional knowledge with the non-traditional knowledge of empirical and climate mode based weather forecasts to improve forecasting of TCs, which would ultimately reduce vulnerability and increase adaptive capacity.
Investigation of the Mekong River basin hydrology for 1980–2000 using the YHyM
Publisher: Wiley
Date: 31-01-2008
DOI: 10.1002/HYP.6934
Disconnect between science and end-users as a barrier to climate change adaptation
Publisher: Inter-Research Science Center
Date: 19-11-2013
DOI: 10.3354/CR01181
Development and evaluation of a stochastic daily rainfall model with long-term variability
Publisher: Copernicus GmbH
Date: 22-12-2017
DOI: 10.5194/HESS-21-6541-2017
Abstract: Abstract. The primary objective of this study is to develop a stochastic rainfall generation model that can match not only the short resolution (daily) variability but also the longer resolution (monthly to multiyear) variability of observed rainfall. This study has developed a Markov chain (MC) model, which uses a two-state MC process with two parameters (wet-to-wet and dry-to-dry transition probabilities) to simulate rainfall occurrence and a gamma distribution with two parameters (mean and standard deviation of wet day rainfall) to simulate wet day rainfall depths. Starting with the traditional MC-gamma model with deterministic parameters, this study has developed and assessed four other variants of the MC-gamma model with different parameterisations. The key finding is that if the parameters of the gamma distribution are randomly s led each year from fitted distributions rather than fixed parameters with time, the variability of rainfall depths at both short and longer temporal resolutions can be preserved, while the variability of wet periods (i.e. number of wet days and mean length of wet spell) can be preserved by decadally varied MC parameters. This is a straightforward enhancement to the traditional simplest MC model and is both objective and parsimonious.
The Southern Annular Mode: a comparison of indices
Publisher: Copernicus GmbH
Date: 26-03-2012
Abstract: Abstract. The Southern Annular Mode (SAM) has been identified as a climate mechanism with potentially significant impacts on the Australian hydroclimate. However, despite the identification of relationships between SAM and Australia's hydroclimate using certain data sets, and focussed on certain time periods, the association has not been extensively explored and significant uncertainties remain. One reason for this is the existence of numerous indices, methods and data sets by which SAM has been approximated. In this paper, the various SAM definitions and indices are reviewed and the similarities and discrepancies are discussed, along with the strengths and weaknesses of each index development approach. Further, the sensitivity of the relationship between SAM and Australian rainfall to choice of SAM index is quantified and recommendations are given as to the most appropriate index to use when assessing the impacts of the SAM on Australia's hydroclimate. Importantly this study highlights the need to consider the impact that the choice of SAM index, and data set used to calculate the index, has on the outcomes of any SAM attribution study.
A hydrological model for interprovincial water resource planning and management: A case study in the Long Xuyen Quadrangle, Mekong Delta, Vietnam
Publisher: Elsevier BV
Date: 04-2017
Comparison of published palaeoclimate records suitable for reconstructing annual to sub-decadal hydroclimatic variability in eastern Australia: implications for water resource management and planning
Publisher: Copernicus GmbH
Date: 30-06-2020
Abstract: Abstract. Knowledge of past, current and future hydroclimatic risk is of great importance. However, like many other countries, Australia's observed hydroclimate records are at best only ~ 120 years long (i.e. from ~ 1900 to present) but are typically less than ~ 50 years long. Therefore, recent research has focused on developing longer hydroclimate records based on palaeoclimate information from a variety of different sources. Here we review and compare the insights emerging from 11 published palaeoclimate records that are relevant to annual to sub-decadal hydroclimatic variability in eastern Australia over the last ~ 1000 years. The sources of palaeoclimate information include ice cores, tree rings, cave deposits and lake sediment deposits. The published palaeoclimate information was then analysed to determine when (and where) there was agreement (or uncertainty) about the timing of wet and dry epochs in the pre-instrumental period (1000–1899). The occurrence, frequency, duration and spatial extent of pre-instrumental wet and dry epochs was then compared to wet and dry epochs since 1900. The results show that instrumental records (~ 1900–present) underestimate (or at least misrepresent) the full range of rainfall variability that has occurred, and is possible, in eastern Australia. Even more disturbing is the suggestion, based on insights from the published palaeoclimate data analysed, that 71 % of the pre-instrumental period appears to have no equivalent in the instrumental period. This implies that the majority of the past 1000 years was unlike anything encountered in the period that informs water infrastructure, planning and policy in Australia. A case study, using a typical water storage reservoir in eastern Australia, demonstrates that current water resource infrastructure and management strategies would not cope under the range of pre-instrumental conditions that this study suggests has occurred. When coupled with projected impacts of climate change and growing demands, these results highlight some major challenges for water resource management and infrastructure. Though our case study location is eastern Australia, these challenges, and the limitations associated with current methods that depend on instrumental records that are too short to realistically characterise interannual to multidecadal variability, also apply globally.
The importance of understanding drivers of hydroclimatic variability for robust flood risk planning in the coastal zone
Publisher: Informa UK Limited
Date: 2013
Historical and future drought impacts in the Pacific islands and atolls
Publisher: Springer Science and Business Media LLC
Date: 05-2021
DOI: 10.1007/S10584-021-03112-1
Abstract: Drought is known as a “creeping disaster” because drought impacts are usually noticed months or years after a drought begins. In the Pacific Island Countries and Territories (PICTs), there is almost no ability to tell when a drought will begin or end, especially for droughts other than meteorological droughts. Monitoring, forecasting and managing drought in the PICTs is complex due to the variety of different ways droughts occur, and the erse direct and indirect causes and consequences of drought, across the PICT region. For ex le, the impacts of drought across the PICTs vary significantly depending on (i) the type of drought (e.g. meteorological drought or agricultural drought) (ii) the location (e.g. high islands versus atolls) (iii) socioeconomic conditions in the location affected by drought and (iv) cultural attitudes towards the causes of drought (e.g. a punishment from God versus a natural process that is potentially predictable and something that can be managed). This paper summarises what is known and unknown about drought impacts in the PICTs and provides recommendations to guide future research and investment towards minimising the negative impacts of droughts when they inevitably occur in the PICTs.
Natural hazards in Australia: droughts
Publisher: Springer Science and Business Media LLC
Date: 19-09-2016
Broadening the Spatial Applicability of Paleoclimate Information—A Case Study for the Murray–Darling Basin, Australia
Publisher: American Meteorological Society
Date: 26-03-2014
DOI: 10.1175/JCLI-D-13-00071.1
Abstract: Recent advances in the collection and analysis of paleoclimate data have provided significant insights into preinstrumental environmental events and processes, enabling a greater understanding of long-term environmental change and associated hydroclimatic risks. Unfortunately, it is often the case that there is a dearth of readily available paleoclimate data from regions where such insights and long-term data are most needed. The Murray–Darling basin (MDB), known as Australia’s “food bowl,” is an ex le of such a region where currently there are very limited in situ paleoclimate data available. While previous studies have utilized paleoclimate proxy records of large-scale climate mechanisms to infer preinstrumental MDB hydroclimatic variability, there is a lack of studies that utilize Australian terrestrial proxy records to garner similar information. Given the immediate need for improved understanding of MDB hydroclimatic variability, this paper identifies key locations in Australia where existing and as yet unrealized paleoclimate records will be most useful in reconstructing such information. To identify these key locations, rainfall relationships between MDB and non-MDB locations were explored through correlations and principal component analysis. An objective analysis using optimal interpolation was then used to pinpoint the most strategic locations to further develop proxy records and gain insights into the benefits of obtaining this additional information. The findings reveal that there is potential for the future assembly of high-resolution paleoclimate records in Australia capable of informing MDB rainfall variability, in particular southeast Australia and central-northern Australia. This study highlights the need for further investment in the development of these potential proxy sources to subsequently enable improved assessments of long-term hydroclimatic risks.
Introduction to the special issue: historical and projected climatic changes to Australian natural hazards
Publisher: Springer Science and Business Media LLC
Date: 21-10-2016
On the relationship between large-scale climate modes and regional synoptic patterns that drive Victorian rainfall
Publisher: Copernicus GmbH
Date: 07-04-2009
Abstract: Abstract. In this paper regional (synoptic) and large-scale climate drivers of rainfall are investigated for Victoria, Australia. A non-linear classification methodology known as self-organizing maps (SOM) is used to identify 20 key regional synoptic patterns, which are shown to capture a range of significant synoptic features known to influence the climate of the region. Rainfall distributions are assigned to each of the 20 patterns for nine rainfall stations located across Victoria, resulting in a clear distinction between wet and dry synoptic types at each station. The influence of large-scale climate modes on the frequency and timing of the regional synoptic patterns is also investigated. This analysis revealed that phase changes in the El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD) and/or the Southern Annular Mode (SAM) are associated with a shift in the relative frequency of wet and dry synoptic types on an annual to inter-annual timescale. In addition, the relative frequency of synoptic types is shown to vary on a multi-decadal timescale, associated with changes in the Inter-decadal Pacific Oscillation (IPO). Importantly, these results highlight the potential to utilise the link between the regional synoptic patterns derived in this study and large-scale climate modes to improve rainfall forecasting for Victoria, both in the short- (i.e. seasonal) and long-term (i.e. decadal/multi-decadal scale). In addition, the regional and large-scale climate drivers identified in this study provide a benchmark by which the performance of Global Climate Models (GCMs) may be assessed.
Links between large-scale modes of climate variability and synoptic weather patterns in the southern Indian Ocean
Publisher: American Meteorological Society
Date: 02-2020
Abstract: Weather systems in the southern Indian Ocean (SIO) drive synoptic-scale precipitation variability in East Antarctica and southern Australia. Improved understanding of these dynamical linkages is beneficial to diagnose long-term climate changes from climate proxy records as well as informing regional weather and climate forecasts. Self-organizing maps (SOMs) are used to group daily 500-hPa geopotential height (z500 ERA-Interim) anomalies into nine regional synoptic types based on their dominant patterns over the SIO (30°–75°S, 40°–180°E) from January 1979 to October 2018. The pattern anomalies represented include four meridional, three mixed meridional–zonal, one zonal, and one transitional node. The frequency of the meridional nodes shows limited association with the phase of the southern annular mode (SAM), especially during September–November. The zonal and mixed patterns were nevertheless strongly and significantly correlated with SAM, although the regional synoptic representation of SAM+ conditions was not zonally symmetric and was represented by three separate nodes. We recommend consideration of how different synoptic conditions vary the atmospheric representation of SAM+ in any given season in the SIO. These different types of SAM+ mean a hemispheric index fails to capture the regional variability in surface weather conditions that is primarily driven by the synoptic variability rather than the absolute polarity of the SAM.
Climatic drivers of Victorian streamflow: Is ENSO the dominant influence?
Publisher: Informa UK Limited
Date: 2009
Tropical cyclone perceptions, impacts and adaptation in the Southwest Pacific: an urban perspective from Fiji, Vanuatu and Tonga
Publisher: Copernicus GmbH
Date: 12-05-2016
DOI: 10.5194/NHESS-16-1091-2016
Abstract: Abstract. The destruction caused by tropical cyclone (TC) Pam in March 2015 is considered one of the worst natural disasters in the history of Vanuatu. It has highlighted the need for a better understanding of TC impacts and adaptation in the Southwest Pacific (SWP) region. Therefore, the key aims of this study are to (i) understand local perceptions of TC activity, (ii) investigate impacts of TC activity and (iii) uncover adaptation strategies used to offset the impacts of TCs. To address these aims, a survey (with 130 participants from urban areas) was conducted across three SWP small island states (SISs): Fiji, Vanuatu and Tonga (FVT). It was found that respondents generally had a high level of risk perception and awareness of TCs and the associated physical impacts, but lacked an understanding of the underlying weather conditions. Responses highlighted that current methods of adaptation generally occur at the local level, immediately prior to a TC event (preparation of property, gathering of food, finding a safe place to shelter). However higher level adaptation measures (such as the modification to building structures) may reduce vulnerability further. Finally, we discuss the potential of utilising weather-related traditional knowledge and non-traditional knowledge of empirical and climate-model-based weather forecasts to improve TC outlooks, which would ultimately reduce vulnerability and increase adaptive capacity. Importantly, lessons learned from this study may result in the modification and/or development of existing adaptation strategies.
Drought and water policy in Australia: Challenges for the future illustrated by the issues associated with water trading and climate change adaptation in the Murray–Darling Basin
Publisher: Elsevier BV
Date: 12-2013
Temporal and spatial variability of the cropping limit in South Australia
Publisher: Inter-Research Science Center
Date: 19-05-2014
DOI: 10.3354/CR01218
How and to what extent does precipitation on multi-temporal scales and soil moisture at different depths determine carbon flux responses in a water-limited grassland ecosystem?
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.SCITOTENV.2018.04.225
Abstract: In water-limited ecosystems, hydrological processes significantly affect the carbon flux. The semi-arid grassland ecosystem is particularly sensitive to variations in precipitation (PRE) and soil moisture content (SMC), but to what extent is not fully understood. In this study, we estimated and analyzed how hydrological variables, especially PRE at multi-temporal scales (diurnal, monthly, phenological-related, and seasonal) and SMC at different soil depths (0-20 cm, 20-40 cm, 40-60 cm, 60-80 cm) affect the carbon flux. For these aims, eddy covariance data were combined with a Vegetation Photosynthesis and Respiration Model (VPRM) to simulate the regional gross primary productivity (GPP), ecosystem respiration (R
Links between the Big Dry in Australia and hemispheric multi-decadal climate variability – implications for water resource management
Publisher: Copernicus GmbH
Date: 11-11-2013
DOI: 10.5194/HESSD-10-13539-2013
Abstract: Abstract. Southeast Australia (SEA) experienced a protracted drought during the mid-1990s until early 2010 (known as the Big Dry or Millennium Drought) that resulted in serious environmental, social and economic effects. This paper analyses a range of historical climate data sets to place the recent drought into context in terms of Southern Hemisphere inter-annual to multi-decadal hydroclimatic variability. The findings indicate that the recent Big Dry in SEA is in fact linked to the widespread Southern Hemisphere climate shift towards drier conditions that began in the mid-1970s. However, it is shown that this link is masked because the large-scale climate drivers responsible for drying in other regions of the mid-latitudes since the mid-1970s, did not have the same effect on SEA during the mid to late-1980s and early-1990s. More specifically, smaller-scale synoptic processes resulted in elevated autumn and winter rainfall (a crucial period for SEA hydrology) during the mid to late-1980s and early-1990s, which punctuated the longer term drying. From the mid-1990s to 2010 the frequency of the synoptic processes associated with elevated autumn/winter rainfall decreased, resulting in a return to drier than average conditions and the onset of the Big Dry. The findings presented in this paper have marked implications for water management and climate attribution studies in SEA, in particular for understanding and dealing with "baseline" (i.e. current) hydroclimatic risks.
An intercomparison of tropical cyclone best-track products for the Southwest Pacific
Publisher: Copernicus GmbH
Date: 19-02-2016
Abstract: Abstract. Recent efforts to understand tropical cyclone (TC) activity in the Southwest Pacific (SWP) have led to the development of numerous TC databases. The methods used to compile each database vary and are based on data from different meteorological centres, standalone TC databases and archived synoptic charts. Therefore the aims of this study are to (i) examine spatial and temporal differences between the TC databases, and, (ii) investigate how changes in observational technology influence the temporal quality of TC records over time. To achieve this, we compare three best-track TC databases for the SWP region (0°–35°S, 135°E–120°W) from 1945–2011: the Joint Typhoon Warning Center (JTWC), the International Best Track Archive for Climate Stewardship (IBTrACS), and the Southwest Pacific Enhanced Archive of Tropical Cyclones (SPEArTC). The results of this study suggest that SPEArTC is the most complete repository of TCs for the SWP region. In particular, we show that the SPEArTC database includes a number of additional TCs, not included in either the JTWC or IBTrACS database. These SPEArTC events do occur under environmental conditions conducive to tropical cyclogenesis (TC genesis). Further, while changes in observational technologies from 1945 have undoubtedly improved our ability to detect and monitor TCs, we show that the number of TCs detected prior to the satellite era (1945–1969) are not statistically different to those in the post-satellite era (post-1970). Although studies on TC intensity should be limited to post-satellite ost-geostationary satellite eras only, this study suggests that SPEArTC data (from 1945) may be used to investigate long-term variability of TC counts and TC genesis locations.
Developing hazard lines in response to coastal flooding and sea level change
Publisher: Informa UK Limited
Date: 03-03-2014
Multi-decadal variability of forest fire risk - eastern Australia
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/WF03034
Abstract: This study investigates the influence that the El Niño/Southern Oscillation (ENSO) and the Inter-decadal Pacific Oscillation (IPO) have on long term daily weather conditions pertinent to high forest fire danger in New South Wales, Australia. Using historical meteorological data for 22 weather stations to compute the daily value of McArthur’s Forest Fire Danger Index (FFDI), it is shown that a strong relationship exists between climate variability, on a range of time scales, and forest fire risk. An investigation into the influence of ENSO on fire risk demonstrates that the proportion of days with a high, or greater than high, fire danger rating is markedly increased during El Niño episodes. More importantly, this study also shows that the already significantly enhanced fire danger associated with El Niño events was even further increased during El Niño events that occurred when the IPO was negative. The potential to use simple indices of climate variability to predict forest fire risk is therefore demonstrated to be significant.
Related Organisations
Related Funding Activities
Discovery Projects - Grant ID: DP220102223
Start Date: 09-2022
End Date: 08-2025
Amount: $443,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Projects - Grant ID: LP120200494
Start Date: 05-2013
End Date: 04-2017
Amount: $300,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP220100606
Start Date: 10-2022
End Date: 09-2025
Amount: $353,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP180102522
Start Date: 04-2018
End Date: 06-2021
Amount: $333,267.00
Funder: Australian Research Council
View Funded Activity