Variation in annual runoff of the Jinghe River as influenced by climate change

Abstract:

Variation in annual runoff of the Jinghe River as influenced by climate change

Jian-xia Chang , Yimin Wang

Institute of Water Resources and Hydroelectric Power, Xi’an University of Technology, Xi’an Shaanxi, China

The characteristics of hydro-climatic changes in the Jinghe River Basin were analysed based on data collected at hydro-meteorological stations for the period 1960–2010. The analytical results revealed an increasing trend of the air temperature in the last several decades, but decreasing trends for streamflow and precipitation. This paper demonstrates the application of TOPMODEL, a rainfall-runoff model to simulate runoff of the Jinghe River Basin. Global climate model participating in Phase 5 of the Coupled Model Inter-comparison Project (CMIP5) has been used to project climate change of the Jinghe River Basin, by the year 2050. The projected temperature and precipitation were integrated into TOPMODEL to simulate runoff under future climate conditions. The projections show that the Jinghe River Basin tends to become warmer. Annual average maximum and minimum temperature would rise by 4.2℃ and 3.8 ℃ under RCP8.5 in the 2040s. Annual precipitation would also increase by 32 mm-68 mm under both scenarios, notably by 68 mm in 2030s under RCP8.5. The change in spring precipitation is most significant with an increase by 8%-29%. Annual average runoff is likely to increase about by -3%, -1% and 1% in the 2020s, 2030s and the 2040s under RCP 8.5 and by 2%, -8% and 15% under RCP 4.5 relative to the baseline (1990-2010).