Remote Sensing and Water Balance Modeling in California Drip-Irrigated Vineyards

Advanced computing technologies are being developed to combine remotely sensed imagery with ancillary data for production of ecological and agricultural "nowcasts" and forecasts. NASA's Terrestrial Observation & Prediction System (TOPS) uses Earth-viewing satellite imagery to generate data fields related to hydrology, meteorology and ecosystem structure and function over regional to global extent, with products posted to the Internet on a daily-to-weekly basis. During the 2005 growing season, TOPS operated in conjunction with a water balance model and high resolution satellite imagery to generate daily nowcast/forecast maps of crop evapotranspiration (ET), soil moisture (SM), and leaf water potential (LWP) throughout a 400 ha California winegrape vineyard. The prototype was designed to enhance grower understanding of the effects of climate, soil water holding capacity, and crop vigor on such crucial factors as soil moisture, crop water stress, and irrigation demand.