Land use/Land cover Changes and Associated Impacts on Water Yield Availability and Variation, Mereb-Gash River Basin in Horn of Africa
- 1State Key Laboratory of Resources and Environment Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A, Datun Road, Chaoyang District, Beijing 100101, China
- 2University of Chinese Academy of Sciences, No. 19A, Yuquan Road, Beijing 100049, China
- 3Hamelamalo Agricultural College, Eritrea National Commission for Higher Education, Keren 397, Eritrea
- 4Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China
- 5Earth Change Observation Laboratory, Department of Geosciences and Geography, University of Helsinki, Finland; petri.pellikka@helsinki.fi (P.P.)
- 6State Key Laboratory for Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China (P.P.)
Climate variability, drought, and deforestation are increasing in the Horn of Africa (HOA). Evaluating land use/land cover (LULC) changes and their impacts on water availability and variation are vital actions for regional land-use planning and water resources management. LULC changes during 2000-2015 were estimated using high resolution Landsat images and Google Earth Engine cloud platform, and land-use dynamics index (K). The impact of LULC change on water yield was evaluated using the InVEST model. The results at regional scale show that there were rapid decreases in the area of forests and barren lands (-K) while there was a drastic increase in built-up area (+K values). The transition was found to decrease from forested land to low biomass with highest and lowest values of 51.13% and 16.7%, respectively. There were similar LULC changes in the Mereb-Gash river basin. The total annual water yield increased for all the catchments during 2000-2015, and reached the peak in 2010. The highest annual water yield decreased in the forested lands from 43.18 million m3 in 2000 to 4.1 million m3 in 2015. There was a strong positive correlation between areal changes (%) and the annual water yield variations (%) in all the LULC types except for the water body, and the correlation was significantly positive for the forested areas (p<0.01). The study demonstrates that the decrease in forested areas and expansion in the built-up areas had large impact on water yield. The impacts may further increase pressure on the ecosystem services, exacerbate water scarcity, and food insecurity unless basic measures are planned and implemented.
Key words: LULC; climate variability; InVEST; annual water yield; K-index
How to cite: Measho, S., Chen, B., Pellikka, P., Guo, L., and Zhang, H.: Land use/Land cover Changes and Associated Impacts on Water Yield Availability and Variation, Mereb-Gash River Basin in Horn of Africa , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1479, https://doi.org/10.5194/egusphere-egu2020-1479, 2020.
