Geographical information system based morphometric analysis of takoli gad watershed, tehri Garhwal, Uttarakhand, India

The quantitative analysis of drainage system is an important aspect of characterization of watersheds. Using watershed as a basic unit in morphometric analysis is the most logical choice because all hydrologic and geomorphic processes occur within the watershed. The geographical position of watershed is 300 14’ to 300 23’ N latitude and 780 37’ to 780 46’ E longitudes. The elevation of the watershed ranges from 605 m to 2278 m. The study was carried out using the method of Horton and Strahler, to rank the stream segments using ERDAS IMAGINE 9.1. The relevant numbers of the streams were entered into the attribute table and all other analyses based on the mathematical formulas. The results indicated that the watershed area is 131.43 km2, The drainage Density ranges from 2.55 to 5.91, Stream frequency ranges from 3.65 to 13.13, Relief ratio ranges from 0.18 to 0.70, Ruggedness number ranges from 0.88 to 4.00 and Drainage texture ranges from 9.30 to 71.68. The results of this analysis would be useful in determining the effect of watershed characteristics such as size, shape, slope of the watershed & distribution of stream net work within the watershed.