Share icon
We propose to demonstrate the feasibility of a fallowed land monitoring service for the Central Valley of California. Shortage of water for irrigation and crop production is a principal impact of drought in the Central Valley, yet there is no source of timely, objective information on the extent of fallowed acreage during the main growing season (April - September) to guide decision making with respect to requests for local water transfers, county drought disaster designations, or state emergency proclamations. Widely varying estimates are put forward by interested parties, though typically without objective supporting evidence. The USDA National Agricultural Statistics Service (NASS) annually produces its Cropland Data Layer from satellite imagery, including a fallowed land class, but it is released too late in the year to support within-season decision making. We will produce monthly county tabulations, maps, and GIS files derived from automated processing of Landsat digital satellite imagery. Data from the Landsat archive will be processed for historical context. Such a capability will identify the extent of changes in fallowed acreage due to water shortage during drought. An important gap in drought impact information will be filled, reducing ambiguity surrounding decision making to activate a range of drought response measures. Ours is a joint effort by USGS, USDA, the California Department of Water Resources (CDWR), and NASA to: 1) Improve the accuracy of algorithms currently used to map fallowed areas; 2) Increase the frequency of fallowed area mapping and related data products; 3) Improve the timeliness of fallowed area data products, to provide the information needed by local, state and federal agencies for within-season decision-making; 4) Develop standard, automated data summaries and data services as needed to facilitate streamlined integration of these new information products into existing mapping and reporting processes. 5) Develop a strategy for standing up an enduring service that is integrated into the long term programs and operations of USGS, USBR, CDWR, and USDA. The proposed project will initially focus on California, and will be conducted in the context of the National Integrated Drought Information System (NIDIS) pilot activity for California, but will be scalable to other states and regions in the U.S. under the NIDIS program. Co-Investigators: James Verdin, U.S. Geological Survey John L Dwyer, U.S. Geological Survey Jeanine Jones, California Department of Water Resources Rick Mueller, USDA NASS Forrest Melton and Lee Johnson, California State University Monterey Bay / NASA Ames Research Center Rama Nemani, NASA Ames Research Center