2050年前长江流域地表水资源变化趋势

利用ECHAM5/MPI-OM气候模式预估2001-2050年长江流域不同排放情景（SRES-A2，A1B，B1）下径流深的变化，分析了长江流域地表水资源量的时空变化特征。结果表明：3种排放情景下长江流域多年平均地表水资源量相差不大，但不同排放情景下年际变化特征较为复杂，且变化趋势有所不同。其中，A2高排放情景下地表水资源量呈缓慢减小的趋势，A1B中等排放情景下变化趋势不明显，B1低排放情景下呈相对最为显著的增加趋势。地表水资源量年代际变化波动幅度也较大，2001-2030年3种情景下地表水资源量总体呈现下降特征，但从2030年起，则均表现出不同程度的增加，最高增幅达7.47%，其中尤以夏季和冬季增加显著。模式预估长江流域未来水资源量仍保持目前水平，水资源空间分布不均匀特征仍较为突出。

Projected Surface Water Resource of the Yangtze River Basin Before 2050

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.