Effect of Land Use Activities on Water Quality and Vegetation Cover Change in Nsooba-Lubigi Wetland System, Kampala City

An assessment of the effect of land use activities on water quality andvegetation coverchange in Nsooba-Lubingi Wetland System in Kampala city was conducted between Julyand October 2020. In order to achieve the set objectives, twelve locations were selectedfrom the Nsooba -Lubingi Catchment. The physico-chemical characteristics of wateralong the catchment area were determined by standard analytical methods.The averagevalues for Total Dissolved Solids across all the land-use types of wetland, built up areasand agriculture were lower than the National Standard (750 mg/l). A similar pattern of theland-use was observed for the parameters Total phosphorous, Biological oxygen demand,Chemical oxygen demand, Total suspended solids and Total organic carbon, where theobserved average values were all below the National Standards of 10 mg/l, 50mg/l,70mg/l, 50mg/l and 50mg/l, respectively. The Total Nitrogen average value for built-upareas (11.27 mg/l) was higher than the national standard of 10 mg/l while the remainingland use types of wetland (8.05mg/l) and agriculture (5.96mg/l) were below that of therecommended standard.GIS and Remote sensing techniques were used to analyze high-resolution satellite imagery captured during 1998, 2008 and 2018. Wetland coveragedeclined by approximately 5 hectares (47.2% to 14.58%) from1998 to 2018. Althoughmost of the measured parameters were below the National standard specified by theUganda National Environmental Management Authorityapart from Total Nitrogen forbuilt-up areas, there is need for close monitoring of the water quality in Nsooba-Lubingicatchment to ensure public health safety. The increased built-up environment in theNsooba-Lubigi wetland affects ecosystems services of the wetland. The buffer zones forflood control and sewage treatment have been turned into built-up environment. Theresults from this study suggest a need to protect the Nsooba-Lubingi catchment for itsimportant ecosystemsservices of flood control and sewage treatment.