Impact of Land Use/Land Cover Change on Watershed Hydrology: A Case Study of Upper Awash Basin, Ethiopia

Abstract

Land use/land cover (LULC) change is one of the important factors which have direct impacts on watershed hydrology. The impact of LULC change on streamflow of Upper Awash watershed was carried out using Soil and Water Assessment Tool (SWAT). The LULC change analysis was performed by using unsupervised classification method using Earth Resources Data Analysis System (ERDAS) imagine 8.5 software. The study results showed that the watershed experienced significant LULC change during 1986 to 2009. SWAT model was calibrated for periods 1986 to 1999 and validated for the periods 2000 to 2009. SWAT model was calibrated and validated for the sensitivity of streamflow parameters. Consequently, ten parameters were identified to be sensitive. Further, this model was utilized to assess the impact of LULC change on streamflow for period 1986 to 2009. The result showed that there was a reasonable agreement between observed and simulated streamflow with coefficient of determination (R2) and Nash-Sutcliffe efficiency values 0.86 and 0.77 for calibration, and 0.84 and 0.76 for validation, respectively. The evaluation of SWAT hydrologic response unit (HRU) due to LULC change showed that monthly streamflow was increased by 16.13 % in wet months and decreased by 20.8 % in dry months between the years 1986 and 2000. While between the year 2000 and 2009, it was increased by 0.92 % and 5.82 % for wet and dry months, respectively. Similarly, surface runoff was found increased and groundwater decreased during the study period. Further, the calibrated model can be utilized to understand risk and reliability of different structures and analysis of climate change, water quality, and sediment yield. Hence, this type of study can be useful for sustainable development in the Upper Awash basin as well as in other regions of Ethiopia.

The Role of Environmental, Land Use, and Spatial Factors in Macroinvertebrate Community Composition in Three River Basins in Ethiopia: A Variation Partitioning Analysis

“…This might be linked to variations in population growth in the catchments that could increase the need for crop cultivation, livestock grazing, and urban development, as also reported by several earlier studies (Beyene et al, 2018;Bussi et al, 2021;Getachew et al, 2020). As an example, a former study identi ed that agricultural land area increased by 39.55% at the expense of other land cover classes while forest area decreased by 42.76% in the Awash River basin from 1986 to 2000 (Beyene et al, 2018). According to (Gaston, 2005), the strain on tropical forests caused by the growing human population is one of the primary causes of biodiversity change and loss.…”

“…For example, agriculture, urbanisation, deforestation, and livestock grazing were found to be severe in the Omo-Gibe and Awash watersheds, contrary to the Abay (Blue Nile), where the forest cover is relatively good (27.86%), all of which resulted in a change in the quality of water and macroinvertebrate composition of streams. This might be linked to variations in population growth in the catchments that could increase the need for crop cultivation, livestock grazing, and urban development, as also reported by several earlier studies (Beyene et al, 2018;Bussi et al, 2021;Getachew et al, 2020). As an example, a former study identi ed that agricultural land area increased by 39.55% at the expense of other land cover classes while forest area decreased by 42.76% in the Awash River basin from 1986 to 2000 (Beyene et al, 2018).…”

Land cover changes in the Upper Great Ruaha (Tanzania) and the Upper Awash (Ethiopia) river basins and their potential implications for groundwater resources

“…It would be worth exploring the impact of this increase in vegetation cover on dry season flow and restoration of Usangu wetland. Similarly, in UARB, Beyene et al (2018) found that streamflow had increased during the wet season and reduced during the dry season, and surface runoff had increased, due to the conversion of natural vegetation to agriculture.…”

Analisis Hubungan Tutupan Lahan Dan Indikator Kesehatan Hidrologi Das Rejoso, Jawa Timur

“…Untuk memperbaiki hidrologi kesehatan DAS, peningkatan tutupan kanopi pohon hingga >55% di dataran tinggi dan >80% di bagian tengah DAS memenuhi syarat sebagai penggunaan lahan yang 'ramah infiltrasi' di wilayah DAS Rejoso (Suprayogo et al, 2020). Hubungan antara perubahan penggunaan lahan dan hidrologi DAS merupakan interaksi yang kompleks dan dinamis yang secara signifikan mempengaruhi kuantitas, kualitas, dan waktu aliran air dalam suatu DAS (Öztürk et al, 2013;Beyene et al, 2018;). Perubahan-perubahan ini dapat memberikan dampak yang besar terhadap karakteristik hidrologi suatu DAS, sehingga berdampak terhadap aliran air sungai melalui lanskap tersebut (Adhami et al, 2019).…”

“…Perubahan-perubahan ini dapat memberikan dampak yang besar terhadap karakteristik hidrologi suatu DAS, sehingga berdampak terhadap aliran air sungai melalui lanskap tersebut (Adhami et al, 2019). Perubahan penggunaan lahan dapat mengubah karakteristik permukaan suatu wilayah sehingga mempengaruhi keseimbangan antara limpasan dan infiltrasi (Beyene et al, 2018). Analisis hubungan antara perubahan penggunaan lahan dan kesehatan hidrologi DAS membantu dalam perencanaan penggunaan lahan, dimana informasi ini memberi dasar pertimbangan alokasi kawasan untuk pembangunan, konservasi, dan pertanian berdasarkan karakteristik hidrologisnya (Dibaba et al, 2020).…”