Development of Geomorphological Permeability Index (GPI) for Assessment of Ground Water Availability and Watershed Measures

The study area consists of three adjacent watersheds namely Barureva, Sher and Umar which conjoin together to form an important southern sub-basin of Narmada basin, MP, India. Morphological parameters of the three watersheds and their corresponding fourth order subwatersheds have been calculated with the help of data attributes generated from relevant GIS analysis. A Geomorphological Permeability Index (GPI) has been proposed which is comprised of watershed morphological parameters such as length ratio (R<Subscript>t</Subscript>), drainage density (D<Subscript>d</Subscript>), drainage frequency (D<Subscript>f</Subscript>) and relief ratio (R<Subscript>h</Subscript>) to assess the nature of permeability of geological formation and ground water recharge potential in 89 subwatersheds of study area. Result and analysis conclude that the high GPI values (>10) indicate the presence of permeable or soft geological formation and consequently assures the presence of good ground water storage. The comparison GPI values with geohydrological data conclude GPI index can also be successfully used to evaluate geohydrological condition of small watersheds in absence of observed field data. On the basis of GPI values ranges, subwatersheds of the study area can be sorted out for identification of ground water recharge areas, rain water harvesting areas and areas require erosion control measures. Copyright Springer Science+Business Media B.V. 2011