Analysis of the spatial distribution of petrol filling stations and their vulnerability to fire hazard using GIS along Kampala jinja high way, from city square to Kireka

Abstract

The rapid increase in rural urban migration and the consequent population and urban growth in the last two to three decades have necessitated the need for more automobiles to enable efficient movement of goods and passengers within and outside Kampala Metropolitan area. This resulted into the proliferation of petrol filling stations due to rise in demand for fuel. This study examined the spatial distribution of petrol filling stations and their vulnerability to fire hazard given their location in densely populated region of the urban area. All the existing filling stations on site were visited and a hand-held Global Positioning System (GPS) was used to collect their locational and attribute information. At the time of the study, a total of sixteen (16) functioning filling stations were identified. A visual analysis of the distribution of filling stations in the study area showed that they are clustered. This observation was confirmed by an Average Nearest Neighbor analysis (spatial statistics tool) used to analyze patterns. Nearest Neighbor Analysis statistics obtained reveals a Nearest Neighbor Ratio of 0.623177, a z-score value of -4.942160 and a p-value of 0.000001 which is highly significant. This by implication signifies that the present pattern of locating filling stations within the study area is fully controlled by some specific activity or land use. Spatial Query and Buffer Analysis were also used to determine the distribution pattern and level of compliance to the setback standards respectively. The result shows a clustered distribution pattern with all filling stations complying with the 15m setback from the road centerline. However, more than 50% have not complied with the 1000m distance apart between consecutive stations. The results show that fuel stations at a distance of less that 15m from the road network are highly vulnerable to fire hazard in case of fire outbreak since the passing vehicles could spark a fire ignition from the highly flammable surrounding fuel station. Also, it can also be concluded that the proximity of buildings to a fuel station is a major potential cause of fire ignition to the neighboring petrol stations mostly buildings at <50m distance from the petrol stations since the buildings could be the potential fire hotspots depending on the land uses. In this study, different parameters were used to assess spatially the vulnerability of fueling stations to fire and four of them were weighted using AHP (that is; slope, temperature, windspeed, land use land cover) and their influences used to generate the fire vulnerability map. The selection of these factors was based on the availability of their data for the study area. After a successful AHP, it was found that slope contributed less (i.e., 7.88%) towards the vulnerability of petrol stations to fire hazard since nearly all the stations are located on a flat surface in their respective geographies wind speed contributed 30.25%, temperature 17.40% and land use 44.47% since the largest area is a built-up area and buildings are being considered potential sources of fire ignition in this case. It is recommended that implementation of setback standards and safety preparedness policies should be improved for sustainable urban development.