Analysis of Rainfall in Assessing Drought Using Remote Sensing & Geographical Information System - A Case Study of Gulbarga District in Karnataka (India)

Rain is the only source of water on theearth and for conserving this precious resource, the base is the land. A proper planning for safe utilisation and saving of water is the need of the hour. Shortage of rainfall coupled with its erratic distribution during rainy season causes severe water deficit conditions resulting in various intensities of droughts. Drought varies in different parts of the world depending on the amount and reliability of rainfall received in a particular region. Gulbarga district is one of the drought prone districts of the Karnataka State. All the ten talukas of the Gulbarga district were identified as drought prone talukas. For the study of the drought situation, we have taken into consideration 48 years of monthly rainfall data of all the ten talukas of the Gulbarga district, from 1961 to 2008, and using this data basic rainfall statistics have been worked out. Data created in GIS (Geographical Information System) is used as a base for analysing the rainfall and predicting the occurrence of droughts in the district. The basic rainfall statistics have been worked out considering the 48 year time period (from 1961 to 2008) monthly rainfall data of all the ten talukas of the Gulbarga district. The mean annual rainfall in this region varies between 776–791 mm. The results of 5 yearly average showed a decrease in the annual rainfall @ 3.44 mm per year. The lowest rainfall observed was 366.3, 494.3 and 513.5 mm in 1972, 1971 and 2003 respectively. It was observed that on two occasions the severe drought situation extended throughout the entire district.