基于GCM模型的塔里木河流域未来径流变化研究

Study on future runoff changes in Tarim River basin based on GCM model

为研究塔里木河流域未来降水、气温变化以及径流的响应,本文提出了GCM下RCP2.6、RCP4.5、RCP8.5三种情景与分布式水文模型SWAT相对接的研究方案。采用气候模式输出的降水、气温等资料作为SWAT模型输入数据,分析了未来2020—2050年流域降水、气温与径流变化规律。结果表明:在RCP2.6情景下,各子流域降水大多表现为增加趋势,在RCP4.5情景下降水表现出减少趋势,在RCP8.5情景下降水趋势性不明显;在不同RCP情景下,各子流域温度均呈现明显上升趋势,且升温情况随着RCP情景对应辐射强迫的增加而增加;2020—2050年,阿克苏河与和田河年径流增加明显,且增加量从RCP2.6情景到RCP8.5情景逐渐增大,叶尔羌河年径流存在一定增加,但幅度并不显著;开都河年径流变化不大;塔里木河上游三源流径流在未来均呈现明显丰水状态;开都河径流呈现丰枯交替现象。研究结果可为流域水资源规划和管理提供重要参考。

In order to study the future precipitation,temperature changes and runoff responses in the Tarim River basin,three scenarios of RCP2.6,RCP4.5 and RCP8.5 under GCM are proposed to connect with the distributed hydrological model SWAT.Based on the data of precipitation and temperature from climate model as input data of SWAT model,the variation law of precipitation,temperature and runoff in the basin from 2020 to 2050 is analyzed.The results show that under the RCP2.6 scenario,the precipitation in each sub-asin mostly shows an increasing trend,while under the RCP4.5 scenario,the falling water shows a decreasing trend,while under the RCP8.5 scenario,the falling water trend is not obvious.Under different RCP scenarios,the temperature of each sub-basin shows a significant upward trend,and the temperature rise increases with the increase of radiation forcing corresponding to RCP scenarios.From 2020 to 2050,the annual runoff of Aksu River and Hotan River increased obviously,and the increase gradually increased from RCP2.6 scenario to RCP8.5 scenario.The annual runoff of Yarkant River increased to some extent,but the range was not significant,and the annual runoff of Kaidu River did not change much.In the future,the runoff from the upper reaches of the Tarim River will be obviously abundant,and the runoff from the Kaidu River will be alternately abundant and dry.The research results can provide important reference for watershed water resources planning and management.