Use of Morphological Characteristics for Multi-Criteria Evaluation through Fuzzy Analytical Hierarchy Process for Prioritization of Watersheds

Abstract

Identification of prospective zones for planning and management of conservation measures at micro level to conserve available natural resources are primary requisite for sustainable development, particularly in the fragile semi-arid tropics. Establishment of control measures over the entire watershed at similar instance is unattainable / uneconomical; therefore, it is a prerequisite to apply viable techniques for prioritization of sub-watersheds (SWDs). Keeping this in view, an attempt has been made to study various morphological characteristics and applied multiple criteria decision making (MCDM) through Fuzzy Analytical Hierarchy Process (FAHP) and Geographical Information System (GIS) techniques for identifying critical / priority sub-watersheds falling in transaction zone between mountainous and water scarcity region of Western Part of India. The morphometric characterization over eight sub-watersheds was obtained through the measurement of distinct linear, areal and relief aspects of the sub-basins. The morphometric analysis showed the relationship among various characteristics of the watershed and performs a significant role in determining topographical and hydrological behavior of the basin. Ranking of each hydrological unit was carried out for preferential soil and water conservation measures with respect to the value and weightages obtained by deriving the relationships between the qualitative morphometric parameters obtained from classifying the sub-watersheds by combining the robustness of fuzzy logic and the Analytical Hierarchy Process (AHP). The results of FAHP analysis showed that Circulatory Ratio, Form Factor and Elongation Ratio are observed to be the most important factors for vulnerability of soil and water resources over the basin. On the basis of FAHP approach, sub-watersheds were considered as vulnerability assessment units and were alienated into four prioritization levels: low, modium, high and very high levels. The evaluated results illustrate that 57.67 % of sub-watersheds (five sub-watersheds) are in the moderately and highly susceptible zones, which indicates potential areas for abrupt provision of soil and water conservation interventions for the efficient watershed management planning. The sensitivity analysis as well as a comparison between the FAHP technique and the earlier outcomes obtained with conventional techniques, such as AHP and compound parameter method, were also studied. The FAHP based technique is a viable approach in illustrating the dilemma and will be useful to various stakeholders such as rural extension community, agriculturists and water resources managers for better decision making with an obliging rule based system for implementing various assessment measures.