基于长江上游流域82个气象站点的实测数据和国际耦合模式比较计划第5阶段(Coupled Model Intercomparison Project phase 5,CMIP5)的2种排放情景下的8个气候模式1961～2099年的降水、气温数据,通过等距离累积分布函数法(Equidistance Cu...基于长江上游流域82个气象站点的实测数据和国际耦合模式比较计划第5阶段(Coupled Model Intercomparison Project phase 5,CMIP5)的2种排放情景下的8个气候模式1961～2099年的降水、气温数据,通过等距离累积分布函数法(Equidistance Cumulative Distribution Function Method,EDCDFm)进行气候模式的统计降尺度。在此基础上,构建0.5°×0.5°网格空间分辨率的可变下渗容量水文模型(Variable Infiltration Capacity,VIC),对历史流量进行模拟,并进一步模拟分析长江上游流域2006～2099年径流量、蒸散发的时空演变趋势。结果表明:VIC水文模型能够较好地模拟研究区的水文过程,从长江上游流域未来时期(2006～2099)主要水文过程变化趋势的预测来看,径流量变化趋势不明显、蒸散发呈增加趋势。此研究对于合理规划配置长江流域水资源及为气候影响评价和决策系统提供科技支撑具有重要意义。展开更多
基于长江流域宜昌站以上集水区的气象站实测数据,采用等距离累积分布函数法(Equidistance Cumulative Distribution Function Method,EDCDFm),对国际耦合模式比较计划第5阶段(Phase Five of the Coupled Model Intercomparison Project ...基于长江流域宜昌站以上集水区的气象站实测数据,采用等距离累积分布函数法(Equidistance Cumulative Distribution Function Method,EDCDFm),对国际耦合模式比较计划第5阶段(Phase Five of the Coupled Model Intercomparison Project 5,CMIP5)的2种排放情景下(RCP4.5,RCP8.5)8个气候模式模拟的降水和气温进行统计降尺度。在此基础上,采用平均绝对误差、相对偏差和相关系数评估EDCDFm模拟结果与历史阶段(1961-2005年)实测站点数据的模拟精度,并对长江上游流域降水和气温的变化进行趋势分析。结果表明EDCDFm降尺度的模拟结果与实测值的拟合程度高,月降水相关系数达到0.89以上,月平均气温的相关系数在0.98以上;2种排放情景下,长江上游未来时期(2010-2099年)的降水、气温均呈增加趋势,且气温显著性增加。展开更多
Based on LMDZ4 daily temperature dataset,equidistant cumulative distribution function matching method(EDCDFm)and cumulative distribution function-transform method(CDF-t)are used to evaluate the ability of models in si...Based on LMDZ4 daily temperature dataset,equidistant cumulative distribution function matching method(EDCDFm)and cumulative distribution function-transform method(CDF-t)are used to evaluate the ability of models in simulating extreme temperature over central and eastern China.The future temperature change is then projected.The results show that the EDCDFm and CDF-t methods function effectively correct the spatial distribution of daily mean temperature and extreme temperature,significantly reduce the biases of the model simulation and effectively improve the capacity of models for spatial pattern of extreme temperature.However,the cold bias of the CDF-t method in winter is obviously higher than that of the EDCDFm method,and the temperature change curve of the EDCDFm method is closer to the observation than that of the CDF-t method.The projection based on the EDCDFm method shows that under the RCP4.5 emission scenario,the temperature in the study area shows a warming trend.Relative to 1986e2005,the mean temperature is projected to increase by 0.76,1.84,and 2.10℃during 2017e2036,2046e2065,and 2080e2099,respectively.The spatial change for the mean,maximum,and minimum temperature in the three future periods have good consistency;warming in northern China is higher than that in the south.Uncertainties in temperature projection are large in the Tibetan Plateau and Sichuan Basin.Frost days decrease significantly,especially in the Tibetan Plateau,and the frost days in the three periods decrease by more than 15,30,and 40 d,respectively.The variation of heat wave indice is the smallest;the increase of heat wave is mainly in eastern China,and the increase in South China is more than 2 d.Besides,under the global warming of 1.5℃and 2℃,the response characteristics of extreme temperature over central and eastern China are also analyzed.The results show that the mean temperature,maximum temperature and minimum temperature in the study area increase by more than 0.75℃under 1.5℃target and over 1.25℃under 2℃target,especially in the northwestern China and the Tibetan Plateau,relative to 1986e2005.Additionally,comparing two warming targets,the difference of three temperature indices in parts of northeastern China is over 1.5℃,while more than 3 d for heat wave.展开更多
The latest Coupled Model Intercomparison Project Phase 6(CMIP6)proposes new shared pathways(SSPs)that incorporate socioeconomic development with more comprehensive and scientific experimental designs;however,few studi...The latest Coupled Model Intercomparison Project Phase 6(CMIP6)proposes new shared pathways(SSPs)that incorporate socioeconomic development with more comprehensive and scientific experimental designs;however,few studies have been performed on the projection of future multibasin hydrological changes in China based on CMIP6 models.In this paper,we use the Equidistant Cumulative Distribution Function method(EDCDFm)to perform downscaling and bias correction in daily precipitation,daily maximum temperature,and daily minimum temperature for six CMIP6 models based on the historical gridded data from the high-resolution China Meteorological Forcing Dataset(CMFD).We use the bias-corrected precipitation,temperature,and daily mean wind speed to drive the variable infiltration capacity(VIC)hydrological model,and study the changes in multiyear average annual precipitation,annual evapotranspiration and total annual runoff depth relative to the historical baseline period(1985–2014)for the Chinese mainland,basins and grid scales in the 21st century future under the SSP2-4.5 and SSP5-8.5 scenarios.The study shows that the VIC model accurately simulates runoff in major Chinese basins;the model data accuracy improves substantially after downscaling bias correction;and the future multimodel-mean multiyear average annual precipitation,annual evapotranspiration,and total annual runoff depth for the Chinese mainland and each basin increase relative to the historical period in near future(2020–2049)and far future(2070–2099)under the SSP2-4.5 and SSP5-8.5scenarios.The new CMIP6-based results of this paper can provide a strong reference for extreme event prevention,water resource utilization and management in China in the 21st century.展开更多
文摘基于长江上游流域82个气象站点的实测数据和国际耦合模式比较计划第5阶段(Coupled Model Intercomparison Project phase 5,CMIP5)的2种排放情景下的8个气候模式1961～2099年的降水、气温数据,通过等距离累积分布函数法(Equidistance Cumulative Distribution Function Method,EDCDFm)进行气候模式的统计降尺度。在此基础上,构建0.5°×0.5°网格空间分辨率的可变下渗容量水文模型(Variable Infiltration Capacity,VIC),对历史流量进行模拟,并进一步模拟分析长江上游流域2006～2099年径流量、蒸散发的时空演变趋势。结果表明:VIC水文模型能够较好地模拟研究区的水文过程,从长江上游流域未来时期(2006～2099)主要水文过程变化趋势的预测来看,径流量变化趋势不明显、蒸散发呈增加趋势。此研究对于合理规划配置长江流域水资源及为气候影响评价和决策系统提供科技支撑具有重要意义。
文摘基于长江流域宜昌站以上集水区的气象站实测数据,采用等距离累积分布函数法(Equidistance Cumulative Distribution Function Method,EDCDFm),对国际耦合模式比较计划第5阶段(Phase Five of the Coupled Model Intercomparison Project 5,CMIP5)的2种排放情景下(RCP4.5,RCP8.5)8个气候模式模拟的降水和气温进行统计降尺度。在此基础上,采用平均绝对误差、相对偏差和相关系数评估EDCDFm模拟结果与历史阶段(1961-2005年)实测站点数据的模拟精度,并对长江上游流域降水和气温的变化进行趋势分析。结果表明EDCDFm降尺度的模拟结果与实测值的拟合程度高,月降水相关系数达到0.89以上,月平均气温的相关系数在0.98以上;2种排放情景下,长江上游未来时期(2010-2099年)的降水、气温均呈增加趋势,且气温显著性增加。
基金Funding for this study was provided by the National Key R&D Program of China(2017YFA0603804)and the National Natural Science Foundation of China(41230528).
文摘Based on LMDZ4 daily temperature dataset,equidistant cumulative distribution function matching method(EDCDFm)and cumulative distribution function-transform method(CDF-t)are used to evaluate the ability of models in simulating extreme temperature over central and eastern China.The future temperature change is then projected.The results show that the EDCDFm and CDF-t methods function effectively correct the spatial distribution of daily mean temperature and extreme temperature,significantly reduce the biases of the model simulation and effectively improve the capacity of models for spatial pattern of extreme temperature.However,the cold bias of the CDF-t method in winter is obviously higher than that of the EDCDFm method,and the temperature change curve of the EDCDFm method is closer to the observation than that of the CDF-t method.The projection based on the EDCDFm method shows that under the RCP4.5 emission scenario,the temperature in the study area shows a warming trend.Relative to 1986e2005,the mean temperature is projected to increase by 0.76,1.84,and 2.10℃during 2017e2036,2046e2065,and 2080e2099,respectively.The spatial change for the mean,maximum,and minimum temperature in the three future periods have good consistency;warming in northern China is higher than that in the south.Uncertainties in temperature projection are large in the Tibetan Plateau and Sichuan Basin.Frost days decrease significantly,especially in the Tibetan Plateau,and the frost days in the three periods decrease by more than 15,30,and 40 d,respectively.The variation of heat wave indice is the smallest;the increase of heat wave is mainly in eastern China,and the increase in South China is more than 2 d.Besides,under the global warming of 1.5℃and 2℃,the response characteristics of extreme temperature over central and eastern China are also analyzed.The results show that the mean temperature,maximum temperature and minimum temperature in the study area increase by more than 0.75℃under 1.5℃target and over 1.25℃under 2℃target,especially in the northwestern China and the Tibetan Plateau,relative to 1986e2005.Additionally,comparing two warming targets,the difference of three temperature indices in parts of northeastern China is over 1.5℃,while more than 3 d for heat wave.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0206)the National Key Research and Development Program of China(Grant No.2017YFA0603703)+1 种基金the National Natural Science Foundation of China(Grant No.4200011953)the fundamental scientific research fund of China Institute of Water Resources and Hydropower Research(Grant No.JZ110145B0052021)。
文摘The latest Coupled Model Intercomparison Project Phase 6(CMIP6)proposes new shared pathways(SSPs)that incorporate socioeconomic development with more comprehensive and scientific experimental designs;however,few studies have been performed on the projection of future multibasin hydrological changes in China based on CMIP6 models.In this paper,we use the Equidistant Cumulative Distribution Function method(EDCDFm)to perform downscaling and bias correction in daily precipitation,daily maximum temperature,and daily minimum temperature for six CMIP6 models based on the historical gridded data from the high-resolution China Meteorological Forcing Dataset(CMFD).We use the bias-corrected precipitation,temperature,and daily mean wind speed to drive the variable infiltration capacity(VIC)hydrological model,and study the changes in multiyear average annual precipitation,annual evapotranspiration and total annual runoff depth relative to the historical baseline period(1985–2014)for the Chinese mainland,basins and grid scales in the 21st century future under the SSP2-4.5 and SSP5-8.5 scenarios.The study shows that the VIC model accurately simulates runoff in major Chinese basins;the model data accuracy improves substantially after downscaling bias correction;and the future multimodel-mean multiyear average annual precipitation,annual evapotranspiration,and total annual runoff depth for the Chinese mainland and each basin increase relative to the historical period in near future(2020–2049)and far future(2070–2099)under the SSP2-4.5 and SSP5-8.5scenarios.The new CMIP6-based results of this paper can provide a strong reference for extreme event prevention,water resource utilization and management in China in the 21st century.
