Assessing the impact of rainfall variation on water resources in Iganga district, Uganda

Abstract

Rainfall is one of the key weather and climate elements that affect most economic activities especially in the tropics. Therefore understanding of local rainfall patterns, its variability between seasons and across years, and its relationship with changes in wetland extents and community perceptions are critical for local planning of economic activities such as subsistence agriculture, fishing that are major livelihoods for the local people. This study aimed at understanding the trends of rainfall patterns and how it relates with the community perceptions. Landuse and land cover of Lumbuye wetland was used to determine the changes in extent of wetland coverage which was correlated with community perceptions. The study utilized meteorological rainfall data for the years 1990-2018, Landsat images (1995 – 2020) and community interviews. The study results reveal a declining trend in MAM rainfall compared to an increasing trend of SON rainfall However, these trends in seasonal rainfall are not significant because of low values of R2 (R2 = 0.0308 and R2 = 0.032 for MAM and SON respectively) The study also noted more rainfall variability in SON (CV = 0.3) compared to MAM (CV = 0.25). Overall, there is very low variability in annual rainfall of Iganga district (CV = 0.14). Results further show that Lumbuye wetland declined by 24.7%, while agriculture increased by 20.3% between 1995 and 2020 and this was supported by 61% of the community respondents who revealed that wetlands had declined in the same period. 38% and 24% of the respondents believe that declining rainfall and increasing agriculture respectively are majorly associated with decline in size of wetland resources of the area. The declining rainfall trend in wet seasons therefore has severe implications on water resources in the study area. With the current trends, the future of water resources as well as the extent of wetlands in Iganga district is uncertain. The impact of these changes will be reflected in the declined food security, and the over reliance on natural resources for immediate survival.