Land use/cover change and pollution loadings into Kiha River Watershed Hoima District, Western Uganda

Abstract

This study was carried out to i) determine the trend in land use/cover change in Kiha River Watershed (KRW) between 1986 and 2014. ii) determine the variation of pollution loads (TP, TN, TSS) from River Kiha to Lake Albert; and iii) determine the temporal pattern of pollution loadings into Kiha river watershed. A series of Landsat images were used to analyze the land use/cover situation of the study area between 1986 and 2014. Water samples were collected from Kiha River at various sampling points between 8 and 12 pm twice a month, a period covering dry and wet seasons. Rusensa sampling point is located at the outlet of river Kiha, and receives all the water coming through the KRW before entering into river Kafu. SWAT model was used to estimate sediment and nutrient loads for the different periods. The study established that there has been total destruction of forest cover at the expense of agriculture, human settlement and economic activity during the last 20 year period. Although most of the parameters were within the national standards the study observed an increase in the pollution loadings particularly TP and TN over a 20year period and significant variations in the other parameters indicative of high levels of pollution. High values of physico-chemical parameters were recorded at the outlet of the watershed indicating the increase in pollution loadings out of the watershed. The study concluded that there has been a marked change in land use/cover as a result of increased human activity mainly sugarcane growing and processing, agriculture and settlement leading to deforestation and increased levels of pollution in the catchment. The study recommended urgent interventions including but not limited to reforestation, integrated land use methods improved farming methods and better effluent disposal methods to avert the looming calamity in the Kiha River Watershed.