密云水库近30a入库水资源量日益减少,严重影响城市供水和可持续发展,其中气候变化对水资源的影响成为最受关注的问题之一。以海河流域密云水库的水资源供应为例,研究了气候变化对入库水资源的影响。结果表明:除SRESA2情景下在2025年入库流量减少外,其他情景均表现为人库流量增加。对入库流量增加的情景,采用“零调整方案”,即不采取调整措施是可以的,但由于未来北京水资源压力较大,有必要采取一些综合对策。通过多目标条件分析,为解决北京的饮用水供应问题,建议采用开源(跨河流调水)、节流(水田改旱地)及污水治理三管齐下的方案。
A screening framework for assessing impacts of climate change on water resource of Miyun reservoir is briefly introduced. It is a systematic step-by-step scheme for assessing the impact of climate change and its adaptation responses. The assessment shows that water inflow to Miyun reservoir has been decreasing in recent years due to rainfall change and human activities. Climate change is projected to increase the reservoir's inflow in the long term (2050), but the inflow may continue to decline in the medium term (2025) under the SRES A2 scenario, necessitating adaptation measures to assure water supply to Beijing. Suggested comprehensive measures for adaptation management include: 1) converting paddy fields in the upper reaches to rain-fed farming land, with compensation paid to farmers; 2) constructing a water diversion channel of 160 km from the Luanhe River to the Chaohe River, which feeds Miyun reservoir; 3) constructing sewage treatment plants to increase effluent re-use.