Abstract: Based on projected runoff depth of ECHAM5/MPI-OM climate model for the Yangtze River basin under different GHG emission scenarios (SRES-A2, A1B, B1) in 2001-2050, the temporal and spatial patterns of future surface water resource in the Yangtze River basin were analyzed. The results show that the long-term average annual surface water resources of the Yangtze River under three scenarios are similar, while interannual fluctuations are complicated with different trends. The surface water resource declines gradually in fluctuation under the A2 scenario, shows no obvious trend under the A1B scenario, and displays a relatively significant increasing trend under the B1 scenario. Decadal variations of the surface water resource are notable, showing an overall decline trend under all the three scenarios in 2001-2030, while an increase trend to varying extent after the 2030s, especially in summer and winter. The projected future water resource in the Yangtze River remains the current level, showing an evident spatially uneven feature.

Key words: projection, climate change, surface water resource, GHG emission scenario, the Yangtze River basin