Assessing placement bias of the global river gauge network
Krabbenhoft, C., G. Allen, P. Lin, S. Godsey, D. Allen, R. Burrows, A. DelVecchia, K. Fritz, M. Shanafield, A. Burgin, M. Zimmer, T. Datry, W. Dodds, C. Jones, M. Mims, C. Franklin, J. Hammond, S. Zipper, A. Ward, K. Costigan, H. Beck, AND J. Olden. Assessing placement bias of the global river gauge network. Nature Sustainability. Nature Publishing Group, New York, NY, 5:586–592, (2022). https://doi.org/10.1038/s41893-022-00873-0
The objective of the study was to see to what extent streamflow gauge placement are biased and if so, in what ways. Gauges were disproportionately placed on large, perennial, regulated rivers that drained watershed with high human populations and footprints. Streamflow gauges were underrepresented in non-perennial, smaller streams, and in desert and polar regions. Biased streamflow data collection leads to a skewed view of river systems, including their management, protection, and restoration. The results should be considered in future strategic placement of new streamflow gauges.
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.