Development of unimpaired flows for mountain basins draining to the Bay Delta
The objective of this study is to develop daily historical climate surfaces and simulate unimpaired basin discharge, including surface water flow and baseflow, from all basins that drain to the Bay Delta. Basin drainage will be calibrated to DWR reconstructed flows, and comparisons of results will be made with other independently developed watershed models for basins in which they coincide. A second phase of this project will use the calibrated model along with future climate projections to simulate future basin drainage to the Bay Delta.
Climate change is impacting water resources in California and changes in snowmelt and streamflows are challenging the management of water that drains from mountain basins to the San Francisco Bay Delta. The California Dept. of Water Resources (DWR) has reconstructed unimpaired flows to the Delta for water management planning. However, in order to develop future climate projections for which only precipitation and air temperature are available, there is a need to construct historical unimpaired flows using climate data so that comparisons between historical and future can be made on datasets developed using the same methodology.
The objective of this study is to develop daily historical climate surfaces and simulate unimpaired basin discharge, including surface water flow and baseflow, from all basins that drain to the Bay Delta. Basin drainage will be calibrated to DWR reconstructed flows, and comparisons of results will be made with other independently developed watershed models for basins in which they coincide. A second phase of this project will use the calibrated model along with future climate projections to simulate future basin drainage to the Bay Delta.
The U.S. Geological Survey California Water Science Center (USGS), in cooperation with Dept. of Water Resources will develop and analyze daily historical climate and hydrology datasets for 1922-2010. (1) The current monthly Basin Characterization Model (Thorne and others, 2012) will be recalibrated to DWR reconstructed flows and the current BCM snow calibration (Flint and Flint, 2007) will be revised. Analyses of the monthly model will be done to evaluate the sensitivity of basin discharge to changes in soil moisture and potential evapotranspiration. (2) Daily maps of precipitation and air temperature will be developed for the study period using daily station data and monthly maps of PRISM climate and will be compared with other daily datasets. This will be documented in an OFR. (3) A daily BCM model will be developed for 21 basins that drain to the Bay Delta, calibrated to DWR reconstructed daily flows for 1922-2010, and compared to existing SWAT and PRMS models for basins in which they coincide. The daily model will be documented as a SIR BCM Manual.
This project will consider several priority water-resource issues identified in Circular 1309 (USGS, 2007), including developing tools with which to predict ecosystem change on the basis of water availability, quantifying, forecasting, and securing freshwater for our future, and, in particular, assessing the consequences of climate change. This proposal will also support capabilities within the California Water Science Center (CAWSC) to develop hydrologic modeling tools relevant to the present science issues underlying the management of watersheds and hydrologic hazards in light of changes expected under future climate conditions. This project relates explicitly to the mission of WRD to provide scientific information that will be utilized by decision-makers to effectively manage the landscape and water resources for water-related natural hazards, recreational and ecological use, aquatic health, and environmental quality. In addition, the development of these regional-scale modeling tools describing the hydrologic response to climate are relevant to other federally managed lands in California for optimization of water resources.
The objective of this study is to develop daily historical climate surfaces and simulate unimpaired basin discharge, including surface water flow and baseflow, from all basins that drain to the Bay Delta. Basin drainage will be calibrated to DWR reconstructed flows, and comparisons of results will be made with other independently developed watershed models for basins in which they coincide. A second phase of this project will use the calibrated model along with future climate projections to simulate future basin drainage to the Bay Delta.
Climate change is impacting water resources in California and changes in snowmelt and streamflows are challenging the management of water that drains from mountain basins to the San Francisco Bay Delta. The California Dept. of Water Resources (DWR) has reconstructed unimpaired flows to the Delta for water management planning. However, in order to develop future climate projections for which only precipitation and air temperature are available, there is a need to construct historical unimpaired flows using climate data so that comparisons between historical and future can be made on datasets developed using the same methodology.
The objective of this study is to develop daily historical climate surfaces and simulate unimpaired basin discharge, including surface water flow and baseflow, from all basins that drain to the Bay Delta. Basin drainage will be calibrated to DWR reconstructed flows, and comparisons of results will be made with other independently developed watershed models for basins in which they coincide. A second phase of this project will use the calibrated model along with future climate projections to simulate future basin drainage to the Bay Delta.
The U.S. Geological Survey California Water Science Center (USGS), in cooperation with Dept. of Water Resources will develop and analyze daily historical climate and hydrology datasets for 1922-2010. (1) The current monthly Basin Characterization Model (Thorne and others, 2012) will be recalibrated to DWR reconstructed flows and the current BCM snow calibration (Flint and Flint, 2007) will be revised. Analyses of the monthly model will be done to evaluate the sensitivity of basin discharge to changes in soil moisture and potential evapotranspiration. (2) Daily maps of precipitation and air temperature will be developed for the study period using daily station data and monthly maps of PRISM climate and will be compared with other daily datasets. This will be documented in an OFR. (3) A daily BCM model will be developed for 21 basins that drain to the Bay Delta, calibrated to DWR reconstructed daily flows for 1922-2010, and compared to existing SWAT and PRMS models for basins in which they coincide. The daily model will be documented as a SIR BCM Manual.
This project will consider several priority water-resource issues identified in Circular 1309 (USGS, 2007), including developing tools with which to predict ecosystem change on the basis of water availability, quantifying, forecasting, and securing freshwater for our future, and, in particular, assessing the consequences of climate change. This proposal will also support capabilities within the California Water Science Center (CAWSC) to develop hydrologic modeling tools relevant to the present science issues underlying the management of watersheds and hydrologic hazards in light of changes expected under future climate conditions. This project relates explicitly to the mission of WRD to provide scientific information that will be utilized by decision-makers to effectively manage the landscape and water resources for water-related natural hazards, recreational and ecological use, aquatic health, and environmental quality. In addition, the development of these regional-scale modeling tools describing the hydrologic response to climate are relevant to other federally managed lands in California for optimization of water resources.