Impact of land use and land cover dynamics on ecologically-relevant flows and blue-green water resources

Abstract

Understanding how changes in land use and land cover classes influence the portioning of rainfall into blue and green water resources as well as land use dynamics on ecologically pertinent flows are vital for sustainable water resource management and ecology. Guder catchment, one of the tributaries of the Upper Blue Nile Basin in Ethiopia, was considered for the conduction of ecohydrological modeling using land use land cover maps and the Soil and Water Assessment Tool (SWAT). Cultivation land is expanded while forest and plantation are declined, consequently blue water component increased while the green water component declined in the study catchment. Besides, the decline in low flow specially during months of dry period and increase in high flow during rainy season could have negative consequences for ecology. Therefore, sustainable land and water management at catchment level is essential to protect an ecosystem and for sustainable water resources management. The vital resilience capacity of the ecosystem to accommodate alteration without loss of consistency should be maintained. Change in green water due to land use land cover affects biological functions in terrestrial ecosystem as green water is closely linked with biological functions and rainfed agriculture. The approach applied in the present study to investigate the land use and land cover change impact on blue and green water flows as well as on ecological pertinent streamflows can be simply implemented in other river basin systems.