Eleventh International Conference on Climate Change: Impacts & Responses

Abstract

The surface area of Lake Wamala, one of the significant small (about 180km2) fresh water lakes in central Uganda, has been shrinking since 1990. However, there is no significant water abstraction for irrigation or hydro-power generation, implying that the reduction could be due to land cover change and climate variations. This study evaluated the impact of climate and land cover change on Lake Wamala surface area. Modified Normalized Difference Water Index (MNDWI) was employed to delineate the lake area from Landsat Enhanced Thematic Mapper (ETM+) images for the period of 1990-2017. Land use maps were developed from Landsat images using maximum likelihood classifier, while a Mann-Kendall test was used to determine the trends in surface area, rainfall, temperature and land cover change. Results show a no trend in rainfall, a slight increase in temperature and an increase in agricultural and built-up land for the period of 1990-2017. The lake’s surface area significantly shrunk between 1990- 1995, while the period 1995-2017 is marked with a rebound in the lake. The fluctuations in the surface area are attributed more to land cover change rather than climate variations.