南水北调中线工程水源区水文循环过程对气候变化的响应

Simulated hydrologic responses to climate change of water source area in the Middle Route of South-to-North Water Transfer Project

以南水北调中线工程水源区为研究流域,基于数字高程模型、土地利用和土壤类型等资料,采用1980—1990年日资料进行模型参数率定和检验,研究了SWAT模型在该流域的适用性;根据联合国政府间气候变化专业委员会第四次评估报告中大气环流模型多模式输出结果,分析了特别排放情景下21世纪降水、气温、径流、蒸发的响应过程。结果表明:与基准期相比,南水北调中线工程水源区21世纪气温将持续增高,年降水量将增加,径流量较基准期将出现先减少后增大的趋势,21世纪40年代年径流量开始较基准期增加,预示着水源区的水资源在21世纪前期将出现减少,21世纪中后期将增加。未来气候变化对南水北调中线工程水源区径流变化影响不大,总体来看有利于南水北调中线工程的调水。

The change of surface water resources in the water source area of the Middle Route of South-to-North Water Diversion Project in the future will directly affect the reliability of the whole project. It is an important basis for trans-valley water resources deployment and management. Based on the digital elevation model, land used information and soil type data in the water source area of the Project, the applicability of the SWAT model in this basin is investigated by using the observation data obtained from 1980 to 1987 to calibrate the parameters of the model. According to the Fourth Assessment Report of multi-mode climate model results for the Intergovernmental Panel on Climate Change, the responsed precipitation, air temperature, runoff and evaporation under different Special Report on Emissions Scenarios in the 21st Century is analyzed. Compared with the baseline period, The analysis results show that the temperature and the annual precipitation will continue to increase, but the runoff in the catchment will be reduced at first and then increased, the runoff will begin to increase in the forties of the 21st Century. The result indicates that the water resources will reduce in the early 21st Century and will increase in the mid-late. The future climate change will have a little influence on the runoff of the water source area, and thus will generally be favorable to the South-to-North Water Transfer Project.