Prioritization of Sub Watershed Based on Morphometric Characteristics Using Fuzzy Analytical Hierarchy Process and Geographical Information System – A Study of Kallar Watershed, Tamil Nadu

Abstract

Watershed prioritization has gained importance in natural resources management, especially in the context of watershed management. Delineation of watersheds within a large drainage basin and their prioritization is required for proper planning and management of natural resources for sustainable development. Delineation of potential zones for implementation of conservation measures above the entire watershed at similar occurrence is inaccessible as well as uneconomical; therefore it is a prerequisite to apply viable technique for prioritization of sub watersheds (SW). The present research attempted to study various morphological characteristics and to implement Geographical Information System (GIS) and Multi Criteria Decision Making (MCDM) through Fuzzy Analytical Hierarchy Process (FAHP) techniques for identification of critical sub watersheds situated in transaction zone between mountainous and water scarcity region of kallar watershed, Tamil Nadu. The morphometric characterization was obtained through the measurement of three distinct linear, areal and relief aspects over the eleven sub-watersheds. The morphometric characterization showed vital role in distinguishing the topographical and hydrological behavior of the watershed. Each morphometric parameters were ranked with respect to the value and weightings obtained by deriving the relationships between the morphometric parameters obtained through classification of the SW by associating the strength of Fuzzy Analytical Hierarchy Processes (FAHP). Based on FAHP approach, sub watersheds were evaluated and divided into five prioritization zones: very less, less, medium, high and very high classes. The FAHP techniques is a practical approach for identification of the sensitive priority zones and is useful for better management practices such as implementation of land and water resource management, conservation and sustainable agricultural development.