Monitoring Agricultural Drought in Canada using the Vegetation Drought Response Index (VegDRI)

Abstract:

Drought conditions vary tremendously from place to place and week to week. Accurate and timely agricultural drought monitoring is essential to understand each drought event, its progression and potential effects, and to provide information to support drought mitigation decisions. Monitoring is improved by integrating information that is timely and region-specific to identify droughts where and when they are happening. The Vegetation Drought Response Index or VegDRI, currently operational across the lower-48 states of the U.S., is a hybrid drought monitoring and mapping tool. VegDRI models integrate satellite observations of vegetation status and climate data with information on land cover, soil characteristics, and other environmental factors to isolate the specific effects of drought on satellite-measured vegetation condition. Developed by the U.S. Geological Survey Earth Resources Observation and Science Center and the National Drought Mitigation Center, this index has been applied in the U.S. since 2009 to support national drought monitoring. Recently, the method has been adapted for application in southern Canada using a much sparser in situ climate network and satellite-derived data from the Moderate Resolution Imaging Spectroradiometer. Current research showing VegDRI models and maps in adjacent regions of Canada and the U.S. highlighted the sensitivity of VegDRI to known agricultural drought events in Canada over a 15 year period. Preliminary results showed 71% agreement in drought classes between the two countries, with 98% of pixels within 2 categories.