Urban Land Suitability Analysis for Residential Areas using Geospatial techniques: A Case Study of Dire Dawa city, Ethiopia

Abstract

Urban land suitability analysis for particular land use is the preliminary task in the context of urban land use planning and development. However, land suitability analysis, by its nature is a complex process and involves considerations of multi-criteria evaluation which considers not only physical conditions but also environmental, social, and economic factors. Hence, this study aimed to analyze urban land suitability for residential areas in Dire Dawa city, using geospatial techniques and multi-criteria evaluation. Eleven factors namely: land-use land-covers, built-up, slope, aspect, flood plains, road, water supply, electric transmission, healthcare service, soil, and recreational area and ten constraints including built up, heavy industries, airport, railway station, military camp, cemeteries, waterbody, fault lines, high voltage electric stations, and high-tension electric lines were evaluated and prioritized as per judgment of urban planning experts. Factors were weighted in a hierarchical order using the analytical hierarchy process approach in IDRISI selva software to produce their weights of importance to the land suitability for a residential area. Boolean overlay tool of ArcGIS 10.7 software was used to incorporate all layers of constraints to produce a composite constraint map. Weighted overlay analysis of ArcGIS 10.7 software was adopted to integrate all weighted factors and multiplied with constraint map to produce the final suitability map. The final suitability map classified the whole Dire Dawa city area into five suitability classes. Accordingly,55.78% area covers unsuitable,1.22% area covers less suitable, 4.56% area covers moderate suitable, 34.63% area covers high suitable and 3.81% area covers very high suitable. To validate the suitability of the proposed residential land use plan of the city, the plan was compared with the final suitability map. The validated result of the study reveals 8.156% and 33.376% of proposed residential land use plan which are still undeveloped exist under very high suitable and high suitable respectively whereas 42.57% (287 km2) areas of proposed land uses are already developed while 15.57% (1.05km2) area of proposed residential land use is undeveloped but categorized under restriction areas. Therefore, the final suitability map provides a useful guide for the proposed residential land use. Thus, the study implies the effectiveness of geospatial techniques and MCE to handle land suitability analysis aimed at identifying environmentally safe and economically feasible sites for residential areas. The study would support the planning efforts being made to improve residential land provision, and also supports the government in formulating ef ective policies to the context.