Estimation of geomorphological characteristics of raigad district using geospatial technology

Geographic information system (GIS) technique is a powerful tool that enables planners and decision makers to address current problems and future challenges effectively. GIS techniques have been adopted for the Estimation of Geomorphological characteristics and analyzing their properties of the Raigad district in Maharashtra, India. The study focuses mainly on the major six watersheds with an area of 6982.323 km2 out of total area of Raigad district (7152 km2). It is located between North 17o 51´ to 19o 80´ latitudes and East 72o 51´ to 73o 40´ longitudes. Annual rainfall over the district ranges from 2200 mm to more than 3000 mm in plains and it is above 5000 mm in the hills. The mean minimum temperature is 17.7oC and mean maximum temperature is 31.8oC. Various linear, areal and relief aspects of all the watersheds were calculated. The analysis revealed that the total number as well as total length of stream segments of first order stream is maximum than that of other higher order streams. The total number of streams and their length decreases as the order increases. Horton’s law of stream numbers and stream length also holds good. The bifurcation ratio varies from 1.675 to 4.2 and the elongation ratio varying from 0.679 to 0.827, indicating that watersheds of elongated type have high relief and steep slopes.