CS(AR)-6/99-2000 : Estimation of geomorphology parameters for small catchments using GIS

Abstract

Stream channel morphology is literally the study of stream channel form and structure, but generally it is taken to mean their form and structures regarded as a whole or their collective morphology features. Systematic analysis of morphometry of any drainage basin and its stream system is of great importance in understanding hydrological behaviour of the basin. Geomorphologists have developed parameters, which describe the topology, the structure, the planform and the relief of stream networks.

The important geomorphological parameters which represent the linear, areal and slope aspects of the catchment are required to be evaluated either from Survey of India toposheets or from existing maps. Application of Geographic Information Systems (GIS) package provides an efficient and accurate means for evaluation of these characteristics. In this study geomorphologic characteristics of various bridge catchments using GIS, have been determined using GIS. For the present study Luni subzone 1 (a) has been selected. The morphological parameters have been estimated using GIS for five catchments located in the subzone. GIUH based approach has been applied for one of the catchments and design flood has been estimated. The peak value of unit hydrograph obtained using this approach is comparable with the value given in Flood estimation report for Luni sub zone 1(a) prepared by CWC.