This is an evolving drought monitoring tool, which, in its present form is based entirely on remote sensing data. It aims to supply timely information on drought onset, progression and areal extent. This near-real-time drought monitoring and reporting system currently covers Afghanistan, Pakistan and western parts of India. The system is based on drought-related indices derived from high resolution remote-sensing data (MODIS).
The unique feature of the system is the use of earlier established relationship between drought-related indices obtained from MODIS and AVHRR data. These data types have different pixel resolution and optical characteristics (Thenkabail et al, 2004). The results ensure the continuity of the two data sets and should allow the reports on drought development in the region to be made in near-real time with a spatial resolution of 500 meters and at 8 or 16 days interval.
Images of any index for any date since 2002 and for any districts (or entire study area) can be FREELY downloaded.
Current structure and functionality
Behind SADM is a comprehensive data base of digital remote sensing data, which includes the series of datasets (one or each date and for each index).
New images of the entire study area and individual districts/provinces in three countries are uploaded to SADM every 16 days.
The user can examine the drought-related ground cover condition at three levels:
- in the entire region
- at the district/province level, and
- at the pixel level (0.5 by 0.5 km)
At all three levels, the spatial distribution of the three vegetation characteristics (indices: NDVI, NDVI deviation from the long-term mean and VCI) can be examined.
Regional land-use / land-cover map is also provided.
At the district and pixel level, the time series analysis can be carried out to trace the development of dry or wet conditions. The user can select the time period for display and choose the index and the graph type.