HR: 08:00h
AN: H41G-01 INVITED     [Abstracts]
TI: Regional-scale hydrologic modeling of flow and reactive salt transport in the San Joaquin Valley, CA
AU: * Hopmans, J W
EM: jwhopmans@ucdavis.edu
AF: University of California, Dept. LAWR 123 Veihmeyer Hall, Davis, CA 95616 United States
AU: Schoups, G
EM: gerrit@stanford.edu
AF: Stanford University, School of Earth Sciences Braun Hall, Stanford, CA 94305 United States
AB: A hydro-salinity model was developed to integrate subsurface hydrology with reactive salt transport for a 1,400 km2 study area in the San Joaquin Valley, CA. For the first time, such a modeling framework was used to reconstruct historical changes in salt storage by irrigated agriculture over the past 60 years. We show that patterns in soil and groundwater salinity were caused by spatial variations in soil hydrology, the switching from local groundwater to snowmelt water as the main irrigation water supply, and by occasional droughts. Gypsum dissolution was a critical component of the regional salt balance. Although results show that the total salt input and output were about equal for the past 20 years, the model also predicts salinization of the deeper aquifers, thereby questioning the sustainability of irrigated agriculture.
UR: http://hopmans.lawr.ucdavis.edu/#
DE: 1839 Hydrologic scaling
DE: 1842 Irrigation
DE: 1847 Modeling
DE: 1875 Vadose zone
SC: Hydrology [H]
MN: Fall Meeting 2005