Title: A diagnostic approach to modeling watersheds with human interference
Abstract:
The vast majority of watersheds have some degree of human impacts on hydrological processes. However, these impacts are not accounted for most hydrological models. To incorporate all plausible human impacts comes at a high data acquisition and modeling cost. This raises the question, which human impacts do we need to incorporate to represent observed streamflow patterns at different time scales? To answer this question, we develop a diagnostic approach to modeling watersheds with human interference. This approach builds on the top-down hydrological modeling approach where process complexity is incrementally added to identify which hydrological processes are important in a particular watershed. Here we incrementally add processes through which humans modify hydrology in the context of the Upper Russian River in California, USA. The case of the Upper Russian River where data on changes in water imports, withdrawals, irrigation and agriculture land use is available from the early 1940’s, is an ideal case to develop this method. We find that incorporation of water imports and water rights are sufficient to replicate annual patterns and that adding crop water demand and irrigation enables replication of monthly and daily patterns, while the incorporation of groundwater pumping is not needed. Further, we apply the model to test hypotheses of the drivers of a recent decline in streamflow.
Bio:
Dr. Margaret Garcia is an Assistant Professor in the School of Sustainable Engineering and the Built Environment at Arizona State University in Tempe. Dr. Garcia received her PhD in Civil and Environmental Engineering from Tufts University in 2017. Her research investigates the factors influencing the sustainability and resilience of water systems and works on a range of water resources challenges such as urban flooding, regional water supply reliability, and urban water sustainability. At ASU, Dr. Garcia teaches undergraduate and graduate courses in Hydrology, Socio-Hydrology, Uncertainty Analysis, and Infrastructure Systems. Prior to her time at ASU, Dr. Garcia has worked with the International Institute for Applied Systems Analysis through their Young Scientists Summer Program, in industry as a civil engineer for Arup in their infrastructure group, and volunteered for Engineers Without Borders designing rural water supply systems in Honduras and Peru.
