A spatial decision support tool for identifying evacuation routes for landslide victims

Abstract

Landslides disasters have been a major problem for people living around steep hillsides in many parts of the world such as Mt. Elgon hillsides in Eastern Uganda. Disaster response under such situations has been a challenge especially in the developing countries of the world given the limited resources and inadequate capacities to access GIS technology which technology is now widely and effectively used in all stages of disaster management. Currently in Bududa, it is very difficult to carry out rescue missions, as there are no proper evacuation routes that can be used for effective evacuation of landslides victims. In the process of developing a Spatial Decision Support Tool (SDST) for determining proper evacuation routes for landslide victims, a wide range of secondary data was reviewed while additional information was acquired through formal interviews. There after Model builder and Spatial Analyst tools in ArcGIS were used to develop a model that incorporated basic geographical, social and environmental criteria for generating potential evacuation route corridors which the researcher used to derive possible evacuation routes for landslides victims. In designing the tool, the researcher incorporated procedures followed by the Uganda National Roads Authority to locate new routes, procedures for evacuation of landslide victims, as well as weights attached to geographical, social and environmental criteria related to evacuation route and their ratings. To validate the developed evacuation routes, there was need to carry out “ground truthing”. Since the technique is awfully expensive and time consuming, the researcher mapped the old routes relating their locations with the actual evacuation route corridors generated by the tool. This mapping revealed that most of the old routes, logically designed by communities, actually lay within the evacuation route corridors generated by the tool. The tool was further validated by adjusting weight values assigned to design parameters in the model. It was shown that varying the weights of these design parameters resulted in variation of the evacuation route corridors. This was strong evidence that the tool is flexible and can easily be fine-tuned for successful use in solving the problem of lack of proper evacuation routes for landslides victims in landslide prone areas. The researcher recommends that future research be done on ways of providing early warning systems so as to carry out a pre-evacuation rather than post evacuation. Systems through monitoring landslides activity should also be developed. Other activities such as tree planting, relocation of the people at risk and proper land use planning and management should also be carried out in order to solve the problem of landslide disasters in Bududa.