DECONVOLVING HUMAN AND NATURAL CONTROLS ON STREAMFLOW: AN APPROACH THAT LEVERAGES COMPLEMENTARY DATASETS AND MODELS
Contemporary viewpoints on environmental flows call for mimicking natural flow regimes, implicitly assuming human and natural influences on streamflow are separable. However, even in managed systems, natural streamflow controls can persist. We use complementary datasets to deconvolve natural and human influences on streamflow in the Boise River, Idaho. The snowmelt-dominated upper basin is minimally influenced by humans before the river is impounded in a flood control and storage reservoir system. The lower basin is undergoing rapid urbanization but remains dissected by extensive canals and drains from legacies of irrigated agriculture. We quantify hydrologic variability in the Boise River Basin using output from the Probability of Streamflow Permanence (PROSPER) model and USGS gauges along this natural-human gradient. The convolution of attenuated variability downstream of the reservoir system with a responsive urban system creates a signal more closely resembling a natural hydrograph than would otherwise be expected. Results highlight the need for tools that provide more holistic views of the ways human modification can simultaneously attenuate and increase hydrologic variability, and the ways these activities can be managed towards the aim of improving environmental flow regimes.
Alejandro Flores (Co-Presenter/Co-Author), Boise State University, email@example.com;
Kendra Kaiser (Primary Presenter/Author), Boise State University, firstname.lastname@example.org;