| dc.description.abstract | Lake Victoria water levels rose in the year 2020-2021 resulting in floods that led to massive destruction of property, loss of lives, displacement of people, and interruption in economic activities. The severity of the flooding impacts was attributed to the high population density of Entebbe about 1235 people per square kilometer, and the fact that settlements are in areas prone to flooding. The flood-prone areas are not mapped for proper implementation of policies that restrict settlement in such areas. This paper analyzed the historical Lake Victoria water level data to obtain the maximum water level which was used to identify the affected areas by flood mapping. The impacts of flooding on infrastructure were then assessed in the affected areas.
The 21-year historical water level dataset was fitted on a Generalized Extreme Value distribution to obtain the maximum water level. A DEM was used to identify areas that were flooded and a flood map was produced under the maximum water level event from which impacts on infrastructure were assessed. Using the fitted GEV distribution, return levels of maximum water levels were obtained for different return periods and flood maps were produced to identify areas that could be affected under different scenarios.
A flood map produced for the recorded maximum water level (12.91m) in 2021 resulted in 6.05 sq. km of the flooded area, identifying the most affected villages as Bunono, Old Entebbe Airbase, Kigungu, Mayanzi, Nakiwogo, Virus, Banga-Nakiwogo, Bunonko/Misori along the Western Shoreline of Entebbe. Flood predictions for the 20, 50, and 100-year return periods showed an increase in water levels and the 100-year return level resulted in about 18% of Entebbe being flooded. The study showed that the affected infrastructure included residential homes, hotels, and businesses 56% of this damage was repairable while 25% was uninhabitable with some of the effects being the complete collapse of buildings, settlement of structures, spalling of paint and plaster, and rusting of steel components of buildings. These were associated with the increased cost of damage in repairs and replacements.
The impacts of flooding were severe due to heavy settlements in the flood-prone areas. The results of this study especially flood maps can be used in guiding policies on relocation, preparedness and awareness, and planning of mitigation measures to reduce the impacts caused by flood mapping due to lake water level rises. A similar study using a long-term dataset and a high-resolution DEM can be used to produce reliable results. Similar studies can be extended to areas affected by the same problem. | en_US |
