Site Suitability Analysis for Small Dams for Irrigation and Flood Control in Anaku, Ayamelum Local Government Area, Anambra State

Abstract

Water is an undervalued resource, and dams can mitigate irrigation water scarcity and flood effects. Therefore, this research aims to conduct a site suitability analysis for small dams to tackle the challenges of irrigation and flood control in Anaku, Ayamelum local government area of Anambra State, Nigeria. The objective is to identify suitable sites for constructing small dams using a Geographic Information System (GIS) approach. To achieve this objective, several steps were undertaken. Firstly, a comprehensive land cover/land use feature map was created to understand the existing characteristics of the study area. Criteria for modeling site suitability were then established, including topographic factors (such as slope), geological factors, soil type, land cover/use, precipitation, flow accumulation, and proximity to rivers. The Analytic Hierarchy Process (AHP) was utilized for pair-wise comparisons to assign weights to each criterion. Through ArcGIS, weighted overlay analysis was conducted to combine and assess the various criteria, resulting in a site suitability map that identifies potential locations for small dams based on the summation of weights assigned to each contributing factor. The results indicated that 70% of Anaku was suitable for dam siting, with Umuria identified as the most suitable village in Anaku. This mapping method provides crucial data for decision-makers involved in regional water resources management and sustainable development. It facilitates the determination of optimal sites for constructing new dams, serving purposes such as irrigation and flood control.