Application of the overlay weighted model to determine the best locations for expansion of adigrat town

The objective of this study is to develop Geographic Information System (GIS)-based land suitability analysis model for locating optimal sites for expansion of Adigrat town. In order to determine suitable site, the important factors are incorporated, namely accessibility and topography, land cover, and economic by using overlay weighted method in decision making process. In this paper, Euclidian distance was calculated from roads, streams and existing wells. Aster data was used to classify elevation and slope. Landuse map was prepared using Landsat 8 data. The influence of different factors was given as Elevation 10%, Stream 10%, Wells 10%, Roads 20%, Slope 25% and Landuse 25%. Scale values for criteria were given 1 to 9. Closed distances from wells, Roads, Streams were given higher values. Slope more than 20 degree, Elevation more than 2800 m and Buildup areas were restricted. As a result 3.2 sq. km. of area most suitable and 6.57 sq. km. of area lesser than that was found suitable for urban expansion.