Impact of Land Use/Land Cover Change on Hydrology of the Catchment: The Case of Upper Ribb Catchment, Lake Tana Sub Basin, Ethiopia

Asimamaw Nigusie Asitatikie

doi:10.7176/jees/9-6-02

Abstract

Land use/land cover dynamics has been recognized as one of the factors responsible for altering the hydrologic response of watersheds. Various extent of water resources projects planning and implementation will require knowledge of these changes on catchment hydrology. This study assesses the impact of land use and land cover change effects on stream flow using SWAT model in Upper Ribb Catchment. The analysis of stream flow was done for three different years of 1973, 1995 and 2016 using SWAT model. During the study period of over 43 years (1973 – 2016) stream flow was increased to 6.143m 3 /s due to an increase of cultivated land by 29.947%. Model calibration and validation for stream flow were done at Upper Ribb gauging station. The performance of the model was also checked at this station. Both the monthly calibration and validation results showed good match between measured and simulated stream flow data with the coefficient of determination (R 2 ) of 0.85, Nash-Sutcliffe efficiency (NSE) of 0.824 for the calibration, and R 2 of 0.829 and NSE of 0.814 of the validation period. Keywords : Upper Ribb, Catchment, SWAT, stream flow. DOI : 10.7176/JEES/9-6-02 Publication date :June 30 th 2019

Highlights

The relationship between land use/cover change and watershed hydrology is very complicated, with linkages existing at a wide variety of spatial and temporal scales; but, land use change has a strong influence on global water yield
This study has focused the impact of land use and land cover changes on the hydrology of the Upper Ribb Catchment using soil and water assessment tool (SWAT) model
The result shows that Upper Ribb Catchment has experienced a significant response in stream flow due to land use and land cover over the past 43 years

Summary

Introduction

The relationship between land use/cover change and watershed hydrology is very complicated, with linkages existing at a wide variety of spatial and temporal scales; but, land use change has a strong influence on global water yield. Land cover and use directly impact the amount of evaporation, groundwater infiltration and overland runoff that occurs during and after precipitation events. These factors control the water yields of surface streams and groundwater aquifers and the amount of water available for both ecosystem function and human use (Mustard et al, 2004). Land use/cover changes are highly pronounced in the developing countries that are characterized by agriculture based economies and rapidly increasing human populations. It is caused by a number of natural and human driving forces (Meyer and BL Turner, 1994). Population growth has significant effect on land degradation, poverty and food insecurity in the northern Ethiopian highlands (Pender et al, 2001)

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