“双碳”和“高碳”情景下金沙江中上游流域未来径流模拟

Future runoff simulation in the middle and upper reaches of Jinsha River under“double carbon”and“high carbon”scenarios

受全球气候变化影响,金沙江中上游流域的水文情势发生了较大改变,模拟金沙江中上游流域未来径流,对区域水资源利用具有重要意义。根据中国的“碳达峰”和“碳中和”目标,基于CMIP6的5种全球气候模式(GCMs),耦合SWAT模型和CA-Markov模型,预估了未来“碳达峰”时期(2021—2040年)和“碳中和”时期(2041—2060年)的流域径流变化趋势,为水资源的管理与规划提供理论支撑。结果表明:2021—2060年间金沙江中上游流域呈现暖湿趋势,“高碳”情景下气温和降水量增幅更大。未来土地利用变化表现为除未利用地面积减少之外,其他类型土地面积均有增加。“双碳”情景下年径流量呈现增加趋势,“碳达峰”时期增长率为1.55×10^(8)~2.01×10^(8) m^(3)/a,“碳中和”时期增长率为2.07×10^(8)~4.02×10^(8) m^(3)/a;“高碳”情景下未来时期年径流量呈现减少趋势,“碳达峰”时期减少率为0.99×10^(8)~1.07×10^(8) m^(3)/a,“碳中和”时期减少率为0.85×10^(8)~1.06×10^(8) m^(3)/a;从月平均径流量来看,“双碳”情景下水资源更加丰富,年内分配更为均匀。

Under the influence of global climate change,the hydrological situation in the middle and upper reaches of the Jinsha River has changed greatly.It is of great significance to simulate the future runoff in these reaches for the better utilization of regional water resources.Based on the five global climate models(GCMs)of CMIP6,coupled with SWAT model and CA-Markov model,this study predicts the future runoff trends of the“carbon peak”period(2021-2040)and the“carbon neutrality”period(2041-2060),which can provide a theoretical support for the management and planning of water resources in the basin.The results show that the middle and upper reaches of the Jinsha River Basin present a warm and humid trend from 2021 to 2060,and the increase of temperature and rainfall is more significant under the“high carbon”pathway.In terms of land use change,except for the area of unused land which decreases in the future,the areas of other land use types all increase.Under the the scenario of“double carbon”,the annual runoff in the future shows an increasing trend,with the increasing rate of 155×10^(6)-201×10^(6) m^(3)/a for the“carbon peak”period,and 207×10^(6)-402×10^(6) m^(3)/a for the“carbon neutrality”period;whereas under the“high carbon”scenario,the annual runoff shows a decreasing trend,with the decreasing rate of 99×10^(6)-10^(7)×10^(6) m^(3)/a for the“carbon peak”period and 85×10^(6)-106×10^(6) m^(3)/a for the“carbon neutrality”period.From the perspective of monthly average runoff,water resources are more abundant and more evenly distributed within the year under the“double carbon”scenario.