气候变化对长江上游径流影响预估  

Climate change impacts on runoff in the upper Yangtze River basin

作　　者：秦鹏程[1] 刘敏[1] 杜良敏[1] 许红梅[2] 刘绿柳[2] 肖潺[2] QIN Peng-Cheng;LIU Min;DU Liang-Min;XU Hong-Mei;LIU Lyu-Liu;XIAO Chan(Wuhan Regional Climate Centre, Wuhan 430074, China;National Climate Centre, China Meteorological Administration, Beijing 100081, China)

机构地区：[1]武汉区域气候中心,武汉430074 [2]中国气象局国家气候中心,北京100081

出　　处：《气候变化研究进展》2019年第4期405-415,共11页Climate Change Research

基　　金：国家重点研发计划（SQ2018YFE010367,2016YFE0102400,2018YFC1508001）;湖北省气象局科技发展基金重点项目（2018Z06）;中国气象局气候变化专项（CCSF201911）

摘　　要：利用第五次国际耦合模式比较计划(CMIP5)中5 个气候模式在3 种典型浓度路径(RCPs)下的预估结果驱动SWAT 水文模型,预估了21 世纪气候变化对长江上游年径流量、季节分配以及极端径流的影响。结果表明:预估的长江上游平均气温呈显著上升趋势,21 世纪末较当前(1986-2005 年)升高1.5 ~ 5.5℃,降水总体呈增加趋势,在21世纪30 年代后高于当前气候平均值,21 世纪末相对于当前增加5%~ 15%。流域内气候变化存在明显空间差异,金沙江和岷沱江流域气温升高和降水增加幅度均大于流域平均值。预估的长江上游年径流量及各月平均径流均有增加趋势,在21 世纪30 年代后高于当前多年平均值,21 世纪中期增加4%~ 8%,21 世纪末增加10%~ 15%。预估的径流年内分布的均匀性有所增加,但年际变化明显增大,极端旱涝事件的频率和强度明显增加。预估的各子流域径流变化对气候变化的响应也存在差异,金沙江和岷沱江流域年径流量、年际变化和年内分布变化小,对气候变化的响应表现为低敏感;嘉陵江流域、乌江流域和长江上游干流径流增加幅度大,同时极端丰枯出现的频率和程度增加显著,是气候变化响应的敏感区域。To assess the impacts of climate change on river runoff in the upper Yangtze River basin, the climate change and its impacts on spatial-temporal trend of annual, seasonality and extremes of runoff were examined using Soil and Water Assessment Tool (SWAT) model, based on a subset of five global circulation models under three Representative Concentration Pathways (RCP2.6, RCP4.5, RCP8.5). The projected average annual temperature presents a significant upward trend, with an increase of 1.5-5.5℃ by the end of the 21st century relative to the reference period 1986-2005, and the overall precipitation is projected to increase after 2030s, with an increase of 5%-15% by the end of the 21st century. There is considerable spatial variation in the projected changes in annual temperature and precipitation across the upper Yangtze River basin, with the upper sub-basins (Jinsha River and Mintuo River) having a generally warmer and wetter conditions comparing with the whole study area. Changes of climate will result in an increase in the simulated mean annual runoff in the upper Yangtze River basin after 2030s, with an increase of 4%-8% in middle of the 21st century, and 10%.15% increase by the end of the 21st century. Additionally, the intra-annual distribution of monthly runoff is simulated generally more uniform. However, the inter-annual variation of runoff is simulated to increase, which indicates more frequent and severe extreme flood and drought events. With respect to spatial differences in simulated runoff, the sub-basins of Jinsha River and Mintuo River show a relative small change in the annual water availability as well as the inter-annual and intra-annual variability, whereas the sub-basins of Jialing, Wujiang, and mainstream of the upper Yangtze River show a larger increase in water availability and hydrological extremes.

关 键 词：气候变化 径流 长江上游 SWAT 模型 

分 类 号：P467[天文地球—大气科学及气象学] P333.1[天文地球—水文科学]