Submitted to: Workshop on Computer Applications in Water Management Proceedings
Publication Type: Proceedings
Publication Acceptance Date: October 5, 1995
Publication Date: N/A
Interpretive Summary: Pollutants including fertilizers, pesticides, salts and trace elements, which are related to agricultural activities, pose a significant threat to soil and groundwater resources because of the areal extent of their contamination. To minimize the large-scale impact extent of their distribution in soils and loading to groundwater over time is necessary. Utilizing a geographic information system coupled to a solute transport model, display maps are prepared which predict the distribution of salt in the soil and the loading of salt to the groundwater over a 2400 hectare (i.e., 37 quarter sections) area of the Broadview Water District located on the westside of California's San Joaquin Valley. These maps provide a way to quickly assess he impact of salt upon the soil and groundwater from which irrigation management and reclamation strategies can be developed.
Technical Abstract: Non-point source agricultural pollutants pose a significant environmental threat at local, regional, national and global levels. The continued and necessary use of fertilizers and pesticides to sustain crop productivity, and the natural occurrence of ubiquitous trace elements and salts in irrigated agricultural areas threatens both soil and groundwater resources. The assessment of the environmental impact of these non-point source pollutants related to agricultural activities is needed to minimize environmental deterioration while maintaining agricultural productivity. This is a formidable task due to the added spatial component of non-point source pollutants. A one-dimensional, into the geographic information system ARC/INFO for the purpose of determining areal distributions of salinity in the soil profile and of estimating salt loading to the groundwater. Approximately two-thirds (2396 hectares) of the Broadview Water District located on the Westside of the San Joaquin Valley of central California was used as the test site to evaluate the coupled GIS/solute transport model. Results of the TETrans calculations are presented for a single growing season (1991). Display maps show calculated estimations of salt-loading to groundwater and predictions of potentially salt-affected soils. The maps provide the visual information essential for formulating irrigation management strategies to minimize groundwater pollution, reduce water usage, lower shallow water tables, and reclaim deteriorating soils without adversely impacting crop.