Submitted to: Agricultural Drought Monitoring Strategies in the World
Publication Type: Abstract Only
Publication Acceptance Date: 10/10/2002
Publication Date: 4/16/2003
Citation: Jackson, T. 2003. Passive microwave remote sensing of soil moisture and regional drought monitoring [abstract]. Agricultural Drought Monitoring Strategies in the World. Interpretive Summary: Soil moisture maps, an improved index of drought, and inputs to global climate models are possible through the use of passive microwave remote sensing of soil moisture. These products could provide information on drought potential and severity. Since drought indices and GCMs do not consider actual soil moisture conditions, this approach could have major value for agriculture. The basis for measuring soil moisture using passive microwave remote sensing is presented with a description of alternative techniques for retrieving soil moisture. Current and future satellite systems are reviewed along with examples of soil moisture studies that illustrate how this information can be used in drought monitoring and assessment. Results could improve the accuracy, timing and reliability of the indices and predictions. This is a major goal identified in the National Drought Policy Commission report. As noted in that report, federal interagency efforts to detect drought trends two-weeks in advance is a good start. Longer-term predictions would improve services. Improved warnings of drought would benefit farmers, ranchers, water managers and the markets. These products are highly relevant to the Global Water and Energy Experiment and NRCS National Water and Climate Program. Better assessments would be of both significant economic and environmental value on a national and global basis.
Technical Abstract: Current tools to predict drought, indices and global climate models (GCMs), do not include any direct observations of the soil condition, which is critical for agriculture. Soil moisture and deficit products are now feasible using a new generation of microwave remote sensing satellites. These measurements can be used to measure and monitor the actual soil moisture conditions on a daily basis over the entire Earth. The quality of these products will continue to improve over time as new sensors are launched. These satellite products, combined with existing insitu observations and models, should be exploited in drought monitoring, assessment and prediction. The basis for measuring soil moisture using passive microwave remote sensing is presented with a description of alternative techniques for retrieving soil moisture. Current and future satellite systems are reviewed along with examples of soil moisture studies that illustrate how this information can be used in drought monitoring and assessment. Within the next five years a wide range of new and significantly improved satellites will be launched that will offer new opportunities. These new opportunities should help mitigating the effects of drought can be achieved through better information on the current status (monitoring), prediction of occurrence, and extent of impact.