反照率对冬克玛底冰川径流及物质平衡模拟影响研究  

The impacts of albedo on Dongkemadi Glacier runoff and mass balance simulation

作　　者：冯紫荆 何天豪 汪少勇 何晓波 高红凯 FENG Zijing;HE Tianhao;WANG Shaoyong;HE Xiaobo;GAO Hongkai(School of Geography Science,East China Normal University,Shanghai 200241,China;State Key Laboratory of Cryospheric Science,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]华东师范大学地理科学学院,上海200241 [2]中国科学院西北生态环境资源研究院冰冻圈科学国家重点实验室,甘肃兰州730000

出　　处：《冰川冻土》2022年第3期1053-1062,共10页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(42071081,41801036);西藏自治区科技计划项目(XZ202101ZD0009G);三江源国家公园联合研究专项(LHZX-2020-11,LHZX-2020-10);冰冻圈科学国家重点实验室自主课题(SKLCS-ZZ-2021)资助。

摘　　要：反照率是影响冰川融水径流和冰川物质平衡的重要因素,但仍缺乏考虑反照率对冰川径流及物质平衡模拟效果影响的定量研究。本研究基于自主研发的冰川流域水文模型(FLEXG),在模型中加入反照率和入射短波辐射,以改进模型。利用2005-2014年长江源区冬克玛底冰川流域实测水文气象数据,以及2010-2014年小冬克玛底冰川各高程带物质平衡数据,开展了冰川流域径流和冰川物质平衡的模拟研究。研究发现:考虑反照率和入射短波辐射后,FLEXG模型对日尺度径流的模拟有一定改善,验证期KGE从0.49提高到0.51;冰川物质平衡的模拟也有明显提高,R2从0.67提高到0.83。同时,6-9月冰川径流的贡献从63%提高到66%,与利用同位素信息分割径流的结果更为接近,模拟真实性得到明显提高。Albedo has been considered an important factor affecting the process of glacier runoff and mass balance,but still lack of quantitative studies. In this study,albedo and incoming shortwave radiation are taken into account in the glacier hydrological model FLEXG,and tested in the Dongkemadi River Basin,in the source region of the Yangtze River. To account for spatial heterogeneity,the basin was classified into19 elevation bands at50 m intervals,and was divided into3 different aspects(north facing,south facing and west/east facing)for both glacier and non-glacier regions. Observed hydrology and meteorology data from2005 to2009,MODIS(MOD10 A1)daily albedo product and daily incoming shortwave radiation product during ablation seasons(May-September)were used to force the models,and calibrate the parameters. The hydro-meteorological data and glacier mass balance data from2010 to2014 were used to validate model performance. Monte Carlo sampling was used to generate2×104 sets of parameters within the prior range. Kling-Gupta efficiency(KGE)was used as an objective function to evaluate model performance in calibration. Then the best one percent of parameter sets was regarded as behavioral ones for further analysis and generate uncertainty ranges of the simulated runoff. The results showed that consideration of the albedo and incoming shortwave radiation could increase the model realism,including daily runoff,glacier mass balance,and the glacial runoff proportion. More specifically,the runoff simulation was improved from KGE=0.49 to KGE=0.51,the glacier mass balance simulation was improved from R2=0.67 to R2=0.83;and the glacier runoff proportion was increased from63% to66%,which is closer to the previous result obtained by isotopic hydrograph separation. This study illustrates that considering the albedo and incoming shortwave radiation can improve the performance and model realism of the degree-day factor model.

关 键 词：反照率 入射短波辐射 冰川径流模拟 冰川物质平衡模拟 冬克玛底冰川 

分 类 号：P343.6[天文地球—水文科学]