Remote Sensing of Drought Impacts on Agricultural Production and Fallowing of Agricultural Land in the Western U.S.
Abstract
Over the past two decades, drought events in the western United States have highlighted the vulnerability of the agricultural sector to changes in the frequency or duration of extreme events, and underscored the need to improve monitoring and mitigation of drought impacts on agriculture. We present an application of satellite data to monitor drought impacts on agricultural production in near real-time and quantify fallowing of agricultural land in California, Nevada, and Washington.
A ten-year record of land fallowing in California has been compiled, and accuracy assessments conducted to date have shown that remote sensing can provide consistent and accurate estimates of changes in fallowing of agricultural acreage during drought events. A decision tree algorithm was developed and applied to timeseries of satellite data from Landsat TM/ETM+/OLI, MODIS, and Sentinel-2. Comparisons against data collected during field surveys of 680 fields in California demonstrated errors of +/-10% or less in the monthly and seasonal satellite-derived estimates. We also describe the extension of this approach to the states of Washington and Nevada, including modifications to the algorithms to account for the different crop types and growing seasons in these states, and summarize patterns in land fallowing from 2015 to 2019. Final accuracies for the modified approaches will be calculated at the end of the 2019 growing season using data from field surveys conducted in 2018 and 2019 of 435 fields in Washington, and 300 fields in Nevada. To facilitate transfer to state agencies for operational use, the workflow originally developed on the NASA Earth Exchange was transferred to Google Earth Engine. Co-development of tools for fallowed area mapping with state agency partners has been an important and valuable part of this project, and we describe lessons learned from the development of the approach, the technology transfer process, and application of the data to support drought response.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMPA34A..10M
- Keywords:
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- 1880 Water management;
- HYDROLOGY;
- 4343 Preparedness and planning;
- NATURAL HAZARDS;
- 6309 Decision making under uncertainty;
- POLICY SCIENCES;
- 6620 Science policy;
- POLICY SCIENCES & PUBLIC ISSUES