Geospatial study on morphometric characterization of Umtrew River basin of Meghalaya, India

Geospatial technology that is, remote sensing (RS), geographical information system (GIS) and global positioning system (GPS) have proved to be an efficient tool in the field of modern day geographical and geological studies. GIS and Remote sensing techniques have been adopted for the identification of different morphological features and to analyze their existence in a hilly river basin of Meghalaya plateau, which is located in the two North-East Indian states of Meghalaya and Assam. Morphometric analysis of any drainage basin can be very much effective in determining the landform characteristics and the processes and components behind its development. The morphometric parameters of the study area have been discussed with respect to linear, areal and relief aspects. The geological formation of the basin area varies from Shillong group of rocks in the undulated hilly areas of Meghalaya plateau to unconsolidated river alluvium in the plain parts of Brahmaputra valley. It is a 7th order drainage basin and the entire drainage network can be defined as “Trellis” in nature. It has been observed that the drainage density value is in between medium to low which indicates that the basin has highly permeable sub-soil material and thick vegetative cover in the most of its areas. The moderate values of bifurcation ratio in the basin area indicates the possibilities of structural control over the development of the entire drainage network. The circularity ratio value reveals that the basin is elongated in shape and a predominance of highly permeable homogenous geologic material. The aim of the present study is to find out the various sets of inherent factors which were behind the formation of this river basin and its hydrologic nature.   Key words: Umtrew River basin, drainage, morphometric, hydrologic, geographical information system (GIS).