Browsing by Author "Burgin, Amy J."

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    Assessing placement bias of the global river gauge network
    Krabbenhoft, Corey A.; Allen, George H.; Lin, Peirong; Godsey, Sarah E.; Allen, Daniel C.; Burrows, Ryan M.; DelVecchia, Amanda G.; Fritz, Ken M.; Shanafield, Margaret; Burgin, Amy J.; Zimmer, Margaret A.; Datry, Thibault; Dodds, Walter K.; Jones, C. Nathan; Mims, Meryl C.; Franklin, Catherin; Hammond, John C.; Zipper, Sam; Ward, Adam S.; Costigan, Katie H.; Beck, Hylke E.; Olden, Julian D. (Nature Portfolio, 2022-07)
    Hydrologic data collected from river gauges inform critical decisions for allocating water resources, conserving ecosystems and predicting the occurrence of droughts and floods. The current global river gauge network is biased towards large, perennial rivers, and strategic adaptations are needed to capture the full scope of rivers on Earth. Knowing where and when rivers flow is paramount to managing freshwater ecosystems. Yet stream gauging stations are distributed sparsely across rivers globally and may not capture the diversity of fluvial network properties and anthropogenic influences. Here we evaluate the placement bias of a global stream gauge dataset on its representation of socioecological, hydrologic, climatic and physiographic diversity of rivers. We find that gauges are located disproportionally in large, perennial rivers draining more human-occupied watersheds. Gauges are sparsely distributed in protected areas and rivers characterized by non-perennial flow regimes, both of which are critical to freshwater conservation and water security concerns. Disparities between the geography of the global gauging network and the broad diversity of streams and rivers weakens our ability to understand critical hydrologic processes and make informed water-management and policy decisions. Our findings underscore the need to address current gauge placement biases by investing in and prioritizing the installation of new gauging stations, embracing alternative water-monitoring strategies, advancing innovation in hydrologic modelling, and increasing accessibility of local and regional gauging data to support human responses to water challenges, both today and in the future.
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    Pervasive changes in stream intermittency across the United States
    Zipper, Samuel C.; Hammond, John C.; Shanafield, Margaret; Zimmer, Margaret; Datry, Thibault; Jones, C. Nathan; Kaiser, Kendra E.; Godsey, Sarah E.; Burrows, Ryan M.; Blaszczak, Joanna R.; Busch, Michelle H.; Price, Adam N.; Boersma, Kate S.; Ward, Adam S.; Costigan, Katie; Allen, George H.; Krabbenhoft, Corey A.; Dodds, Walter K.; Mims, Meryl C.; Olden, Julian D.; Kampf, Stephanie K.; Burgin, Amy J.; Allen, Daniel C. (2021-08)
    Non-perennial streams are widespread, critical to ecosystems and society, and the subject of ongoing policy debate. Prior large-scale research on stream intermittency has been based on long-term averages, generally using annually aggregated data to characterize a highly variable process. As a result, it is not well understood if, how, or why the hydrology of non-perennial streams is changing. Here, we investigate trends and drivers of three intermittency signatures that describe the duration, timing, and dry-down period of stream intermittency across the continental United States (CONUS). Half of gages exhibited a significant trend through time in at least one of the three intermittency signatures, and changes in no-flow duration were most pervasive (41% of gages). Changes in intermittency were substantial for many streams, and 7% of gages exhibited changes in annual no-flow duration exceeding 100 days during the study period. Distinct regional patterns of change were evident, with widespread drying in southern CONUS and wetting in northern CONUS. These patterns are correlated with changes in aridity, though drivers of spatiotemporal variability were diverse across the three intermittency signatures. While the no-flow timing and duration were strongly related to climate, dry-down period was most strongly related to watershed land use and physiography. Our results indicate that non-perennial conditions are increasing in prevalence over much of CONUS and binary classifications of 'perennial' and 'non-perennial' are not an accurate reflection of this change. Water management and policy should reflect the changing nature and diverse drivers of changing intermittency both today and in the future.
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    Zero or not? Causes and consequences of zero-flow stream gage readings
    Zimmer, Margaret A.; Kaiser, Kendra E.; Blaszczak, Joanna R.; Zipper, Samuel C.; Hammond, John C.; Fritz, Ken M.; Costigan, Katie H.; Hosen, Jacob; Godsey, Sarah E.; Allen, George H.; Kampf, Stephanie K.; Burrows, Ryan M.; Krabbenhoft, Corey A.; Dodds, Walter K.; Hale, Rebecca; Olden, Julian D.; Shanafield, Margaret; DelVecchia, Amanda G.; Ward, Adam S.; Mims, Meryl C.; Datry, Thibault; Bogan, Michael T.; Boersma, Kate S.; Busch, Michelle H.; Jones, C. Nathan; Burgin, Amy J.; Allen, Daniel C. (2020-05)
    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 examples, 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