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 region: Ba River Basin, Viet Nam. Study focus: The 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 region: Climatic 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).

Keywords

• Land use plan
• Climate stress-test
• MIKE HYDRO Basin
• Ba River Basin