Studying the impacts of deep uncertainties on water resources system in Ba River Basin through the combined use of a climate stress-test and land use change

Abstract

Study regionBa River Basin, Viet Nam. Study focusThe impacts of deep uncertainties on the water resources system in the Ba River Basin are explored through the combined use of a climate stress-test and land use change. The performance of the water resources system is assessed using water supply reliability under various climate conditions and land use. A MIKE HYDRO Basin model is developed with 7 irrigation regions, 45 irrigation users, 8 regular users, 48 reservoirs, and 10 hydropower plants. 40 different combinations of climate conditions and land use change were simulated. New hydrological insights for the regionClimatic and land use change is expected to reduce water supply reliability in the river basin by between 2.1% and 5.2%. The most significant reliability decrease is in Nam Bac An Khe (−29.4%), while the most increase is in Upper Ayun (+10.9%). The spatial variation of climatic change impact is high and is reflected in the reliability range. The reliability range of Upper Ayun and Ayun Pa is narrow (1.2% in Upper Ayun and 0.7% in Ayun Pa). In contrast, the reliability range of Nam Bac An Khe, Krong Pa, Krong Hnang, and Upper Dong Cam is wide (14.3% in Nam Bac An Khe, 12.7% in Krong Pa, 12.4% in Krong Hnang, 11.7% in Upper Dong Cam, and 3.4% in Lower Dong Cam).