ESRL/PSD Seminar Series

The National Oceanic and Atmospheric Administration (NOAA) Hydrometeorology Testbed (HMT) program has deployed a soil moisture observing network in the North Fork (NF) of the American River basin located in northern California. Spring soil dry-down characteristics are examined for years 2008, 2009, and 2010 using soil moisture observations made at four locations within the basin. Analyses of surface air temperature, precipitation, and U.S. Department of Agriculture National Resources Conservation Service USDA NRCS Soil Survey Geographic database (SSURGO) soil surveys have been used to relate the soil moisture observations with soil water storage characteristics in the upper and lower NF American River basin. Regression analysis has been used to model the changes that occur in the upper and lower basin water storage during spring dry down. The results of this study suggest that soil texture as a function of basin elevation plays a dominant role in determining the NF American River basin water storage characteristics. Runoff modifications related to potential climate change shifts in the spatial distribution and form of precipitation falling within the basin and soil texture are discussed.