Impacts of land use/cover change on water resources are the result of complex interactions between diverse sitespecific factors and offsite conditions; standardized types of responses will rarely be adequate. The knowledge of how land use/cover change influence watershed hydrology will enable local governments and policy makers to formulate and implement effective and appropriate response strategies to minimize the undesirable effects of future land use/cover change or modifications. In this research SWAT model was used for analyzing the land use and land cover change of the watershed and its impact on reservoir sedimentation. The main objective of the research was to model the hydrological processes that will predict the impact of land use/cover changes on soil erosion and sedimentation in the Omo-gibe basin. In this paper the influence of land use changes on catchment's sediment yield is observed. The delineated watershed was divided into 62 sub basins and 372 HRUs by the model. Model calibration and validation was done at Abelti station. In addition to this the model efficiency was checked at this station. Based on this values for coefficient of determination (r²), Nash-Sutcliffe model efficiency (NSE) and percentage of bias (PBIAS) were found to be in the acceptable range for 1990 and 2010 land use land cover maps in both calibration and validation period. To analyze the impact of land use change on sediment yield different comparison criteria were applied. The first was selecting sub basins having higher sediment yield and found around the main course of the river. The second was selecting and analyzing sub basins having lower sediment yield and the third criterion was based on availability of varied land use classes specially sub basins covered by forest land. While analyzing the impact of land use/cover in all criteria using 1990 and 2010 land use/cover map, it shows an increase in sediment yield. SWAT estimated the sediment yield from the watershed to the reservoir for both 1990 and 2010 land use/cover maps. Therefore 1.1 M tons annual sediment load was entered to the reservoir during 1990 and 1.3 M tons annual sediment load was entered to the reservoir during 2010 land use/cover data. This shows that there is 16.57% increment of sediment yield in 2010 as compared to 1990 land use/cover data.

Recently water is becoming a vital natural resource that can be used for many things in human life i.e. hydropower generation, sanitation, drinking, irrigation, and transportation. But surface water is not enough to satisfy all demands of humans. So besides surface water, groundwater resource is by far huge in amount and not much exploited yet. Now a day exploitation of groundwater through hydrogeological surveying, identification, and delineation of better groundwater potential areas is implemented in many places of the world to satisfy the need for water. This research was done on the place where it is called the Wolaita zone located in the southern region of Ethiopia. The main objective of this research was to delineate and map the groundwater potential areas in terms of relative groundwater availability. Groundwater potential zone mapping was done using GIS and remote sensing integrated with the analytical hierarchical process to meet the objective. Seven thematic map layers (land use/cover, soil, slope, drainage density, lineament density, rainfall, and geology) were used as an input to the weighted overlay of layers for delineation of groundwater potential zones. As a result, the study area was classified into “poor”, “good” and “very good” groundwater potential zones. Accordingly, “poor” and “good” groundwater potential areas were occupying almost the same percentage from the total area which is 44.19% (198,0445ha) and 44.51% (199,460ha) respectively. But “very good” groundwater potential zones are covering 11.30% (50,652.2ha) of the study area. In this regard better groundwater potential areas were identified in the east and northern east direction of the study area. Wolaita zone was also clustered in 12 woredas and one town. From all twelve woredas, a High percentage of “very good” groundwater potential is found in Boloso sore, Duguna Fango, Boloso bombe and Damot sore woredas and relatively “poor” groundwater potential is situated in Kindo Koyisha, Kindo Didaye, Ofa, Humbo, and Sodo zuriya woredas and the remaining part of Wolaita zone is dominantly covered by “good” groundwater potential in Wolaita zone. Furtherly each woredas were also classified as “poor”, “good” and “very good” groundwater potential zones with their percentage of area coverage. Therefore the identified groundwater potential areas can be used for digging of wells and bore holes, conducting further research, a benchmark for water resource management practice, or as an input for policymakers to make research-based decisions.