Assessment impacts of climate change on annual flow in river basin in the future case study: Nakdong river basin in Korea

Abstract

     Climate change has not only significantly influenced to hydrology process during the last decades but will continue to influence in the future. Its impacts effected significantly on the water resource supply and management in regions in general and especially in small basin. In this study, the main objective is to investigate how the streamflow on river basin will be effected by climate change in annual streamflow, and particularly in terms of the climate change of seasons on different periods in the future in the Nakdong basin, which were based on using hydrological model as the Soil and Water Assessment Tools (SWAT) model. After model was calibrated and validated with observation using monthly streamflow, the future of climate data as three benchmark periods simulated were 2010-2039, 2040-2069 and 2070-2099 were then used as input to the SWAT model to simulate the corresponding future streamflow, then these results are compared with baseline period (1980-2009). Results showed that annual mean streamflow increased for all periods; the significant change is revealed in period of 2040-2069 by comparing with baseline period (1980-2009). However, the streamflow on seasons were determined differences that the streamflow was mainly increased in summer (Jun-Aug) while decreased in autumn (Sep-Nov), which can be cause of more extreme events by flooding in summer and drought in autumn. The results also showed more vulnerable and challenge water resources supply and management in the future in region. In addition, the study can also provide useful support for the sustainable water resources management strategies and policy in river basins.