基于SWAT模型的土地利用和土地覆被变化及气候变化对元江流域径流的影响  

Impacts of land use/land cover change and climate change on the runoff in Yuan River basin based on SWAT model

作　　者：程程 CHENG Cheng(Southwest Forestry University, 650224, Kunming, China)

机构地区：[1]西南林业大学,昆明650224

出　　处：《中国水土保持科学》2020年第5期52-59,共8页Science of Soil and Water Conservation

基　　金：中国气象局气候变化专项“气候变化背景下云南水资源承载力评估研究”(CCSF201736);云南省重点研发计划社会发展领域“气候变化下主要气象对高原特色农业的影响评估及监测预报技术研究”(2018BC007)。

摘　　要：为揭示土地利用和土地覆被变化(LUCC)与气候变化对元江流域径流的影响,在元江流域,采用SWAT模型,设置不同情景定量分析LUCC和气候变化二者对流域径流的影响,并结合RCP4.5和RCP8.5两种排放情景预估元江流域的径流变化。结果显示:SWAT模型适用于元江流域径流模拟,率定期的模型参数R2和纳什效率系数ENS分别为0.63和0.62,验证期的R2和ENS分别为0.62和0.60;土地利用情景模拟显示,各种土地利用类型对径流形成的贡献表现为农业用地最强、草地次之、林地最弱;2006—2015年间元江流域LUCC引起的径流量增加是由林地转化为草地所致,气候变化引起的径流量减少是由降水减少和温度增加共同所致,且气候变化引起的径流减小幅度大于LUCC引起的径流增加幅度,所以元江流域的径流变化是由气候变化主导的;在RCP4.5和RCP8.5两种排放情景下,2021—2050年间元江流域径流减少速率分别是1971—2015年间实测径流减少速率的1.82和2.36倍,且碳排放更高的RCP8.5情景的减少趋势明显高于RCP4.5情景,达到RCP4.5情景的1.3倍。[Background]Yuan River is one of the most important international rivers in Southwest China.Whether the ecological environment of the Yuan River basin is healthy or not has an essential impact on the social and economic development along the coast and the ecological security of other countries in the downstream of the river basin.Therefore,it is of considerable significance to clarify the specific impact of land use/land cover change(LUCC)and climate change on the status of water resources in Yuan River.However,there are few reports on this aspect at present.[Methods]The SWAT model was used to quantitatively analyze the effects of LUCC and climate change on basin runoff,and combined with RCP4.5 and RCP8.5 emission scenarios to predict the runoff change of Yuan River basin.[Results]1)SWAT model is suitable for runoff simulation of the Yuan River basin.The model parameter R2 and ENS(efficiency coefficient of Nash-Sutcliffe)of the calibration period are 0.63 and 0.62,respectively,and the R2 and ENS of the verification period are 0.62 and 0.60,respectively.2)Extreme land-use scenario simulation shows that the contribution of various land-use types to runoff formation is the strongest in agricultural land,the second in grassland,and the weakest in woodland.3)The increase of runoff caused by LUCC in Yuan River basin from 2006 to 2015 is due to the transformation of forest land into grassland.The decrease of flow caused by climate change results from both the reduction of precipitation and the increase of temperature,and the reduction of runoff caused by climate change is more significant than that caused by LUCC.[Conclusions]1)Climate change dominates runoff change in the Yuan River basin between 2006 and 2015.2)Under the two emission scenarios of RCP4.5 and RCP8.5,the runoff reduction rate in the Yuan River basin from 2021 to 2050 is 1.82 times and 2.36 times that of the measured runoff reduction rate from 1971 to 2015,respectively.And the decreasing trend of the RCP8.5 scenario with higher carbon emission is signific

关 键 词：SWAT模型 土地利用和土地覆被变化 气候变化 径流模拟 元江流域 

分 类 号：P933[天文地球—自然地理学]