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

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