University of Twente Student Theses


Hydrological responses to land cover changes in Gilgel Abbay Catchment, Ethiopia

Worku Kebede, Emiru (2009) Hydrological responses to land cover changes in Gilgel Abbay Catchment, Ethiopia.

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Abstract:For the past 30 years an increase in population pressure caused a consistent change in the land cover of the Upper Gilgel Abbay catchment. This was mainly by deforestation as is the case in many other areas of Ethiopia as well The effects of land cover changes have impacted the water balance of the catchment by changing magnitude and pattern of runoff, peak flow and ground water levels. This study is mainly focusing on the assessment of the hydrological response due to the land cover change through satellite remote sensing and Geographic information system (GIS) integrated with the hydrologic modelling. The result of remote sensing assessment on the land cover of the catchment indicated that the forest cover decreased by 1.38 % between the years 1973-1986, while it was 0.92 % between the years 1986-2001. This was mainly due to mainly the expansion of agriculture by 1.53 % and 1.07 % corresponding to the same period. Based on this result, the stream flow records were analysed statistically to evaluate if changes in the land cover affected the hydrological response of the catchment. The result of the analysis indicated that the peak flow increased by 0.901 m3/s and the base flow in the dry season also decreased by 0.053 m3/s during the first period. For the record period the peak flow increased by 0.762 m3/s while base flow decreased by 0.069 m3/s. Generally, the analysis indicated that flow during the wet season has increased, while the flow during the dry season decreased. The HBV model was applied to evaluate the model response to the land cover changes, and the results show that the changes in stream flow characteristics could be relayed to the change of the land cover during the studied period. Key words: Upper Gilgel Abbay, Land cover change, Remote sensing, GIS, Stream flow change; HBV
Item Type:Essay (Master)
Faculty:ITC: Faculty of Geo-information Science and Earth Observation
Programme:Geoinformation Science and Earth Observation MSc (75014)
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