This paper deals with IRS P4 satellite data (ocean colour Monitor), which covers whole of Karnataka. The swath of the satellite is 1420 km. The data   for 2000 and 2001   was used to make a comparative study to understand change in total rainfall and its distribution. As geographers we have tried to give some answers to this change in rainfall pattern.

A rainfall information system for Karnataka was created using Arc view and Arcinfo softwares. The district-wise rainfall database for both the years   were created for performing various spatial queries. This digital database is compatible and can be updated at regular intervals providing a sequential dataset for modeling process and observing the rainfall process and monitoring it. Various suggestions have been   given to the primary sector, which will lead to more utilisation of the rainwater and reduce runoff, which also depletes the surface soil in poorly vegetated stretches. Image processing has been used to find the vegetative cover in both the years so that the variations can be understood and the causes   identified. This basically is an example as to how GIS can be used in different fields to extract the type of output desired. Noticeable change in the rainfall data showed the unpredictability of monsoons.

** Dept. Of Geography, Bangalore University,

* Dept. Of Remote Sensing, Birla Institute Of Technology

Phone: 5561128
E-mail: mrvijaindra@yahoo.co .in