Geographical Information System (GIS) Based Agricultural Drought Assessment:A Knowledge Based Methodology

Agricultural drought is considered to be one of the man's worst natural enemy. Its beginning is subtle, its progress is insidious and its effect can be devastating. In a country like India, drought is considered to be a major factor of uncertainty due to vagarious of monsoon. Once there was not effective drought assessment and monitoring system, but now remote sensing plays an important role and the facilities like Geographic Information System (GIS) facilitate effective drought assessment and monitoring. The methodology list out an assessment and monitoring procedure for Agricultural drought for a given district. Interpretation of satellite based vegetation index (VI) with their ground parameter through GIS. For this study different maps viz, Landuse map, Soil map, Mandal/Municipal map, Hydrogeological map and data's viz Rainfall, Ground water levels, Major Crop sown details, Source wise irrigation details need to be collected, digitised and entered in the database. From the created database agricultural landuse area should be extracted and VI need to be generated. This generated Vegetative Index and the available fortnightly Rainfall data of couple of years from the current years assessment should be plotted against time (fortnightly interval) for the selected mandals/municipalities constituting different crops, soil and rainfall distribution. Based on the normal crop performance of previous years, the relative drought assessment for the current year should be made, and the drought severity level is obtained. The results may isolate few from the selected mandals/municipalities which may fall under mild/moderated drought level.