Spatial multi-criteria decision analysis of planning schemes of a slum community in Ghana

Abstract

Integration of urban planning and Geographic Information System (GIS) is one of the major research focus among geospatial professionals. This is because the rapid increasing rate of urbanisation has created extreme pressure on local governments’ particularly in developing countries and Ghana is no exception. This calls for the implementation of proper planning strategies to reduce congestion in cities and to guarantee quality services to citizens hence the use of the Analytical Hierarchy Process (AHP) and the Grey Relational Analysis (GRA) methods in this work. The AHP was used for allocating weights to the various classes of buildings in order of preference within the study area. A pairwise matrix was formed using the relative importance of each class and then normalised to obtain the respective weights. A consistency check was carried out to show if opinions were consistent with their scoring. The GRA was then employed for the optimal site selection out of a number of proposed roads and parcels considering various criteria. This was done to meet the requirements of the indigenes so as to improve the slummy areas. The consistency ratio for the assigned weights using the AHP is 0.0054 which is < 0.1 showing consistency. The weights obtained for each building type are 51%, 28%, 14%, 7% for “A”, “B”, “C” and “D” respectively. Based on the weights of the building types and other factors considered, the GRA was finally employed for the selection of the optimal parcels and roads. The final result produced by the AHP and GRA has proven that Spatial Multi-criteria Decision Analysis can be used for slum upgrade.