Human activities have modified the environment over the years. Urbanization, agriculture lumbering, mining and other land uses have substantially altered the Earth’s surface. Land use and the resultant change in land cover have significant effects on ecological, environmental and hydrologic systems and processes. An understanding of past and present land-cover change, together with an analysis of potential future change, is necessary for proper management; thus, the need for models. Hydrologic models are primarily used for hydrologic prediction and for understanding hydrologic processes. With recent technological advances, technological based tools such as GIS are incorporated into hydrologic models for assessing the impacts of various land use/cover. Hydrologic models incorporated with GIS can be used to project future land uses/cover to provide an increased clarity, probability or likelihood of potential consequences on ecosystem services such as biodiversity, water quality and climate. This paper critically examines land use/cover, effects of impacts of land use/cover and the use of hydrologic models to assess the impact of land us/cover on runoff and sediment yield. Hence it calls for their use by watershed managers and decision maker as management tool especially in developing countries.
Key words: Land use, land cover, runoff, sediment yield, hydrologic models.