气候变化对疏勒河中游水循环及生态环境的影响分析

Impact of climate change on water resources and hydrologic cycle in middle Shule river basin

采用气候变化A1B,A2和B1三种情景数据,预测河西走廊疏勒河干流2011-2050年出山口径流量,加载到疏勒河中游地表地下水耦合模型,分析人类活动及气候变化对疏勒河中游水循环及生态环境影响趋势。结果表明:未来各排放情景气温均明显升高;降水先减少再增加,但增加趋势不明显;径流量较2000-2010年先减少再增加,其中A1B情景增加量最大,B1增加量最小。总供水量和供水结构与2010年现状相同;由于人类活动影响,渠系入渗、田间回归和地下水开采等变化不大,河流入渗、潜水蒸发、泉沟排泄等均衡项与径流量变化趋势一致。与2010年现状相比,地下水储量先减少后增加,至2050年A1B和A2情景地下水储量增加,而B1情景地下水储量减少。适宜天然植被生长的总面积将减少,植被退化区域主要集中在平原区的东南部。

An empirical model was used to predict the runoff of Shule river from 201 lto 2050 based on climate model products with three emissions scenarios （A1B, A2 and B1）. The coupled surface water and groundwater model were used to simulate and analyze the impacts of climate change and human activities on water resources allocation, groundwater system and ecological environments based on the predicted runoff. The following conclusions were drawn. For the three emissions scenarios in the future, temperature will dramatically increase, precipitation will decrease firstly and then increase, and runoff will decrease firstly and then increase compared with the value in 2000s decade, among which, A1B shows the biggest increase and B 1 shows the smallest increase. Water supply quantity and structure in the future will be almost the same with those of 2010. Under control of human activities, canal infiltration, field return flow, and groundwater pumping show little differences among the three scenarios. Variation of river infiltration, groundwater evaporation, spring outflow will be consistent with that of runoff. Groundwater storage will decrease first then increase compared with 2010 level. By 2050, groundwater storage will increase for A1B and A2, but will decrease for B 1. The area suited for natural plant growth will decrease for all the three scenarios. Vegetation degradation will be mainly concentrated in the southeast part of the plain.