ORCID Profile
0000-0002-8735-5757
Current Organisation
University of Kansas
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Publisher: Wiley
Date: 13-04-2020
DOI: 10.1002/WAT2.1436
Abstract: Streamflow observations can be used to understand, predict, and contextualize hydrologic, ecological, and biogeochemical processes and conditions in streams. Stream gages are point measurements along rivers where streamflow is measured, and are often used to infer upstream watershed‐scale processes. When stream gages read zero, this may indicate that the stream has dried at this location however, zero‐flow readings can also be caused by a wide range of other factors. Our ability to identify whether or not a zero‐flow gage reading indicates a dry fluvial system has far reaching environmental implications. Incorrect identification and interpretation by the data user can lead to inaccurate hydrologic, ecological, and/or biogeochemical predictions from models and analyses. Here, we describe several causes of zero‐flow gage readings: frozen surface water, flow reversals, instrument error, and natural or human‐driven upstream source losses or bypass flow. For these ex les, we discuss the implications of zero‐flow interpretations. We also highlight additional methods for determining flow presence, including direct observations, statistical methods, and hydrologic models, which can be applied to interpret causes of zero‐flow gage readings and implications for reach‐ and watershed‐scale dynamics. Such efforts are necessary to improve our ability to understand and predict surface flow activation, cessation, and connectivity across river networks. Developing this integrated understanding of the wide range of possible meanings of zero‐flows will only attain greater importance in a more variable and changing hydrologic climate. This article is categorized under: Science of Water Methods Science of Water Hydrological Processes Water and Life Conservation, Management, and Awareness
Publisher: Springer Science and Business Media LLC
Date: 15-08-2022
DOI: 10.1038/S41893-022-00940-6
Abstract: Several safe boundaries of critical Earth system processes have already been crossed due to human perturbations not accounting for their interactions may further narrow the safe operating space for humanity. Using expert knowledge elicitation, we explored interactions among seven variables representing Earth system processes relevant to food production, identifying many interactions little explored in Earth system literature. We found that green water and land system change affect other Earth system processes strongly, while land, freshwater and ocean components of biosphere integrity are the most impacted by other Earth system processes, most notably blue water and biogeochemical flows. We also mapped a complex network of mechanisms mediating these interactions and created a future research prioritization scheme based on interaction strengths and existing knowledge gaps. Our study improves the understanding of Earth system interactions, with sustainability implications including improved Earth system modelling and more explicit biophysical limits for future food production.
Publisher: Wiley
Date: 15-02-2022
Abstract: Groundwater pumping can cause reductions in streamflow (“streamflow depletion”) that must be quantified for conjunctive management of groundwater and surface water resources. However, streamflow depletion cannot be measured directly and is challenging to estimate because pumping impacts are masked by streamflow variability due to other factors. Here, we conduct a management‐focused review of analytical, numerical, and statistical models for estimating streamflow depletion and highlight promising emerging approaches. Analytical models are easy to implement, but include many assumptions about the stream and aquifer. Numerical models are widely used for streamflow depletion assessment and can represent many processes affecting streamflow, but have high data, expertise, and computational needs. Statistical approaches are a historically underutilized tool due to difficulty in attributing causality, but emerging causal inference techniques merit future research and development. We propose that streamflow depletion‐related management questions can be ided into three broad categories (attribution, impacts, and mitigation) that influence which methodology is most appropriate. We then develop decision criteria for method selection based on suitability for local conditions and the management goal, actionability with current or obtainable data and resources, transparency with respect to process and uncertainties, and reproducibility.
Publisher: Front Matter
Date: 19-05-2020
DOI: 10.59350/YWAQE-9H090
Publisher: Wiley
Date: 28-01-2020
DOI: 10.1002/HYP.13693
Publisher: Wiley
Date: 30-09-2023
DOI: 10.1002/LOL2.10356
Publisher: Research Square Platform LLC
Date: 03-12-2021
DOI: 10.21203/RS.3.RS-1085622/V1
Abstract: Several safe boundaries of critical Earth system processes have already been crossed by human perturbations. Recent research indicates that not accounting for the interactions between these processes may further narrow the safe operating space for humanity. Yet existing work accounts only for transgression of single boundaries and only a few studies take some of the boundary interactions into account. For future sustainability assessments, it is essential to understand boundary transgressions and their interactions more comprehensively. Here, we explore quantitatively how strongly seven variables, representing Earth system processes relevant to food production, interact with each other, using a structured expert knowledge elicitation. We identify Green water and Land system change as crucial interactive processes through their impacts on multiple relevant processes, while Biosphere integrity-land, freshwater and ocean components appear to be most affected by other Earth system processes, most notably Blue water and Biogeochemical flows. The elicitation also enabled us to map the complex network of mechanisms mediating interactions, to support integrated Earth system and planetary boundaries modelling and assessments. Finally, we created a prioritisation scheme for future research according to the interaction strengths and existing knowledge gaps. Our analysis improves our understanding of Earth system interactions, with clear implications for sustainable use of natural resources such as the biophysical limits for food production.
Publisher: American Geophysical Union (AGU)
Date: 26-01-2021
DOI: 10.1029/2020GL090794
Abstract: Over half of global rivers and streams lack perennial flow, and understanding the distribution and drivers of their flow regimes is critical for understanding their hydrologic, biogeochemical, and ecological functions. We analyzed nonperennial flow regimes using 540 U.S. Geological Survey watersheds across the contiguous United States from 1979 to 2018. Multivariate analyses revealed regional differences in no‐flow fraction, date of first no flow, and duration of the dry‐down period, with further ergence between natural and human‐altered watersheds. Aridity was a primary driver of no‐flow metrics at the continental scale, while unique combinations of climatic, physiographic and anthropogenic drivers emerged at regional scales. Dry‐down duration showed stronger associations with nonclimate drivers compared to no‐flow fraction and timing. Although the sparse distribution of nonperennial gages limits our understanding of such streams, the watersheds examined here suggest the important role of aridity and land cover change in modulating future stream drying.
Publisher: Springer Science and Business Media LLC
Date: 25-04-2022
No related grants have been discovered for Sam Zipper.