Morphometric Analysis and Micro-watershed Prioritization of Peruvanthanam Sub-watershed, the Manimala River Basin, Kerala, South India

Balan VB Rekha, A. V. George, M. Rita


Morphometric analysis is important in any hydrological investigation and it is inevitable in development and management of drainage basin. A critical evaluation and assessment of morphometric parameters and prioritization of micro-watersheds based on water holding capacity of Peruvanthanam sub-watershed have been achieved through measurement of linear, aerial and relief aspects of basins by using remote sensing and GIS techniques, and it necessitates preparation of a detailed drainage map. For prioritization, 9 micro-watersheds are delineated and parameters such as Rb, Dd, Fs,T, Lof and C are calculated separately and prioritization has been done by using the Raster calculator option of Spatial analyst. The analysis reveals that the stream order varies from 1 to 6 and the total number of stream segments of all orders counted as 347, out of which the maximum area (69.16%) is covered by 1st order streams and the minimum (0.29%) by 6th order. Lower values of Rb (linear parameters) in each order, higher values of Bh (0.90), Rh (0.07) and Rn (3.02) (relief parameters), high values of Dd (3.36), Fs (6.15), T (6.82), low values of Lof (0.14) and C (0.30) (aerial parameters) all together reveal that the sub-watershed has a complex structure, mountainous relief, high runoff and low infiltration. The maximum area is covered by high to medium prioritized zones (19.07km2) followed by low to very low (17.75km2) while a  very high to high zone is only 4.72km2.


Key words: linear parameters, relief parameters, aerial parameters, Peruvanthanam sub-watershed

Full Text: Rekha et al._3(57)_erem

Print ISSN: 1392-1649
Online ISSN: 2029-2139