Analysis of meenacil watershed using foss gis tools

Abstract

The 78 kilometre long Meenachil River is the holy river in Kottayam district is the lifeline of several millions of people in the state, but now facing tremendous pressure due to encroachments, sand and clay mining and illegal diversions of water. River is facing Water pollution due to disposal of urban and domestic waste into the river all through the banks of the river especially at urban centres like Erattupetta, Palai, Ettumanoor and Kottayam which is affecting the entire watershed in many different ways. Our study focusing on the watershed analysis of the Meenachil watershed using FOSS GIS tools with freely available remote sensing data. Watershed is an ideal unit for carrying out scientific resource management for ensuring continuous benefits on sustainable basis. GIS has become a useful and important tool for scientific study and management of water resources. Data required for analysis require money and time for its collection. Hence data derived using remote sensing are usually used. However most of the commercial GIS packages are very expensive. Use of FOSS (Free and Open Source Software) GIS tools makes watershed analysis possible without incurring heavy expense on licence fees. In this study watershed has been delineated and drainage network has been extracted by using two globally accepted digital elevation data models. So use of FOSS–GIS tools and free globally accepted data sets require consideration in this context. Based on entire analysis and accuracy of results FOSS-GIS tools and freely available remote sensing data are recommended for watershed analysis.