Abstract:

Based on five global climate model data recommended by The Inter-Sectoral Impact Model Inter-comparison Project (ISI-MIP) and Soil and Water Integrated Model (SWIM), the changes of river discharge under global warming of 1.5℃ and 2.0℃ in main stream of upper reaches of the Huaihe River were analyzed. The research results show as follows: the interannual variation of the runoff in the upper reaches of the Huaihe River decreased first and then increased under global warming of 1.5℃ and 2.0℃. The annual runoff at the global warming of 1.5℃ will increase by 9.5% relative to the reference period (1986-2005), while the increase under global warming of 2.0℃ is even more pronounced, reaching 17%. Secondly runoff in four seasons has an increase compared to the reference period under global warming of 1.5℃ and 2.0℃, and the spring runoff rises the most, reaching 24.4%, and the summer, autumn, and winter gains are 7.1%, 16.1%, and 13.5%, respectively. Under global warming of 2.0℃, the rate of increase of runoff in mainstream of the upper reaches of the Huaihe River in the four seasons is larger than under the global warming of 1.5℃. Finally, the maximum daily runoff of different global climate models differs greatly from each other while the average difference is small. Under global warming of 1.5℃ and 2.0℃, the number of days with daily flow exceeding the design flow of the Wangjiaba sluice, increases compared with the reference period, especially under global warming of 2.0℃, which is 22 times more than the reference period and 5.8 times more than under global warming of 1.5℃.

Key words: Global warming of 1.5℃, Global warming of 2.0℃, Global climate model, SWIM hydrological model, Upstream of Huaihe River, Stream flow