摘要
An attempt has been made to study drainage morphometry and its influence on landform processes, soil physical and land erosion characteristics in Vena river basin of basaltic terrain (Deccan traps), Nagpur district, Maharashtra, Central India. High Spatial Resolution Indian Remote Sensing Satellite (IRS)-ID Linear Image Self Scanning (LISS)-III sensor data of 7 March 2000 in conjunction with Survey Of India (SOI) topographical sheets (1:50,000 scale) were used for systematic analysis of various morphometric, lithological and landform characteristics of the river basin. Morphometric analysis was carried out at sub basin level using Spatial Analysis System (SPANS ver. 7.0) GIS system to analyze the influence of drainage morphometry on landforms, soil depth, drainage, available water holding capacity (AWC) and land erosion characteristics. Ten distinct landforms were identified in the basin based on visual interpretation of satellite sensor data. These are dissected ridges, isolated mounds, linear ridges, escarpments, plateau spurs, subdued plateau, rolling plains, foot slopes, narrow valleys and main valley floor. Very shallow soils exists on dissected ridges, isolated mounds, linear ridges, escarpments and plateau spurs covering the sub basins nos. 1, 5–7, 9, 15 and 16 and are associated with high drainage density (Dd), impermeable geology and high runoff conditions. High drainage density, high bifurcation ratio (Rb) and steep slopes are the main causative factors for the development of well-drained soils. The AWC is low in the soils of higher elevations covering the sub basins 1, 2, 3, 4, 7 and 9 whereas, it is very high at lower elevation in the sub basins nos. 12, 13 and 19. Sub basins nos. 1, 2, 5, 15 and 16, associated with high drainage density, stream frequency (Fu) and texture ratio (T) showed very severe to severe erosion. The analysis reveals that the influence of drainage morphometry is very significant in understanding the landform processes, soil physical properties and erosional characteristics. The study demonstrates that remotely sensed data and GIS based approach is found to be more appropriate than the conventional methods in evaluation and analysis of drainage morphometry, landforms and land resources and to understand their inter-relationships for planning and management at river basin level.