LAND USE POLICY FOR SUSTAINABLE WATER RESOURCES MANAGEMENT: A CASE STUDY IN THE DHIDHESSA RIVER BASIN, ETHIOPIA

Context and background Africa is the second largest continent, which is endowed with enormous renewable and non-renewable natural resources that includes arable land, water, oil, minerals, forest and wildlife. As such, the continent is home for 30% mineral reserves, 8% natural Gas, 12% oil reserves, and 40% gold deposit of the world, and with the greatest workforce globally. Moreover, the climate condition of most parts of the African continent is suitable for agricultural production and habitability. Despite all these potentials, the continent has been severely affected by poverty, and is challenging to eradicate poverty from Africa in 2030, the Sustainable Development Goal number 2. These are mainly because of the unsustainable utilization of natural resources and lack of proper natural resource management policies. Study showed that the continent lost about 195 billion UDS annually of its natural capital due to illicit financial flows, illegal mining, illegal logging, illegal wildlife trade, unregulated fishing and environmental degradation. Moreover, climate change and increasing population exacerbate natural resources degradation. On the other hand, the livelihood of more than 70% of the African, mainly sub-Sharan Africa, directly depends on natural resources without proper land use policy and management systems. Particularly, unsustainable land resource utilization and management, and climate change greatly affects water resources availability in the continent where the effect is high for the least developed counties. This case study aimed at assessing the combined and separate impacts of human-induced land use/land cover and climate changes on water resources availability at River basin scale level. The combined effects of climate and land cover changes influence hydrologic responses of a basin in an offsetting or synergistic manner depending on the nature and severity of the changes. As such, estimating the impacts of these environmental changes on hydrologic responses is crucial for planning sustainable water resources management system. However, such comprehensive study is missing in most basins of Ethiopia particularly in the Dhidhessa River basin (DRB). Goal and Objectives: The aim of this case study is, therefore, to quantify the combined and separate impacts of land cover and climate changes on multiple hydrologic variables for the DRB. Calibrated Soil and Water Analysis Tool (SWAT) model and statistical techniques were integrated for this study. In addition, I am tried to link land use/land cover change, climate change and livelihood in the context of African continent. Methodology: Substantial literature review on land policy in Ethiopia was done, and the status and condition of land and land use policy of the country was assessed. Moreover, relationship between land use change, climate change and livelihood were assessed. In addition, the impacts of human-induced land use and climate change on hydrologic regime were quantified using SWAT model. ABSTRACT Context and background Africa is the second largest continent, which is endowed with enormous renewable and non-renewable natural resources that includes arable land, water, oil, minerals, forest and wildlife. As such, the continent is home for 30% mineral reserves, 8% natural Gas, 12% oil reserves, and 40% gold deposit of the world, and with the greatest workforce globally. Moreover, the climate condition of most parts of the African continent is suitable for agricultural production and habitability. Despite all these potentials, the continent has been severely affected by poverty, and is challenging to eradicate poverty from Africa in 2030, the Sustainable Development Goal number 2. These are mainly because of the unsustainable utilization of natural resources and lack of proper natural resource management policies. Study showed that the continent lost about 195 billion UDS annually of its natural capital due to illicit financial flows, illegal mining, illegal logging, illegal wildlife trade, unregulated fishing and environmental degradation. Moreover, climate change and increasing population exacerbate natural resources degradation. On the other hand, the livelihood of more than 70% of the African, mainly sub-Sharan Africa, directly depends on natural resources without proper land use policy and management systems. Particularly, unsustainable land resource utilization and management, and climate change greatly affects water resources availability in the continent where the effect is high for the least developed counties. This case study aimed at assessing the combined and separate impacts of human-induced land use/land cover and climate changes on water resources availability at River basin scale level. The combined effects of climate and land cover changes influence hydrologic responses of a basin in an offsetting or synergistic manner depending on the nature and severity of the changes. As such, estimating the impacts of these environmental changes on hydrologic responses is crucial for planning sustainable water resources management system. However, such comprehensive study is missing in most basins of Ethiopia particularly in the Dhidhessa River basin (DRB). Goal and Objectives: The aim of this case study is, therefore, to quantify the combined and separate impacts of land cover and climate changes on multiple hydrologic variables for the DRB. Calibrated Soil and Water Analysis Tool (SWAT) model and statistical techniques were integrated for this study. In addition, I am tried to link land use/land cover change, climate change and livelihood in the context of African continent. Methodology: Substantial literature review on land policy in Ethiopia was done, and the status and condition of land and land use policy of the country was assessed. Moreover, relationship between land use change, climate change and livelihood were assessed. In addition, the impacts of human-induced land use and climate change on hydrologic regime were quantified using SWAT model. Results: The study result indicated better performance of SWAT model in simulating water balance components for the DRB. Quantifying the separate and combined effects of land cover and climate changes on multiple hydrologic responses at a local scale, and determining the relative contribution of the changes are the strength of this study. The result further showed substantial land use/land cover changes and climate variability in the DRB during the last three decades. The environmental changes observed in the basin mainly caused by poor land resources management and weak land use policy. Significant changes in hydrologic responses were observed in response to the land cover changes, and the increasing trends of temperature and rainfall observed during the last 30 years in DRB. The result showed increasing actual evapotranspiration (AET), streamflow and surface runoff while decreasing groundwater recharge. Surface runoff was more affected by land cover change than by climate change whereas streamflow and AET were more affected by climate change than land cover change during the last 30 years in the basin. The combined effects of land cover and climate changes played offsetting effect on groundwater recharge and AET. Overall, the simulated hydrologic responses will have negative effects on water resources availability and agricultural production in the basin and the surroundings. Therefore, implementing integrated watershed management strategies like soil and water conservation and afforestation could minimize the negative impact. In addition, proper land use planning, awareness creation, providing alternative livelihood, setting strong land use policy, designing sustainable land resources management and implementing climate change adaptation strategies is highly required for Africa in order to feed its population and bring economic and social growth.