Thursday, November 8, 2007 - 8:30 AM
341-1
Spatial Analysis of Snowpack Water Resources in Sierra Nevada for San Joaquin River.
Snow packs in the Sierra Nevada serve as reservoirs of water that support life in California’s San Joaquin Valley, one of the most food productive regions in the world. According to the recent court agreements, beginning in the fall of 2009, increasing flows will be released from the Friant Dam/Millerton Lake to restore the San Joaquin River for salmon runs besides satisfying the fastest growth of human population in the valley. The goal of this project was to quantify the amount of snowfalls and snowmelt in the Upper San Joaquin River Watershed. The snow pack data were collected from NOAA’s Hydrologic Remote Sensing Center for the Upper San Joaquin River watershed above Friant Dam. Little data were available before the year of 2003. Therefore, this project covers the more recent period from November 2003 to September 2006. The data sets included the observed snow depth in centimeters, the modeled snow depth (where and when measurements were not possible) and the modeled snow water depth in centimeters. A Digital Elevation Model (DEM) and a GRID file for the Upper San Joaquin River Watershed were created in ArcGIS software, and the GRID map was cut into the shape of the watershed for spatial analysis. Using the available data from 31 stations, contour maps of monthly and annual snow depth and snowmelts were created using the Kriging interpolation method and the volumes of water were calculated using 3-D Analysis. These maps enabled visualization of the temporal and spatial changes of the snow packs and the snow melts. Our calculation showed that the cumulative snowfall started to increase in November, maximize in March and diminish in June. The volume of snowmelt started to increase in November, maximize in April and diminish in later September.
Recorded presentation