青藏高原IMS冰雪产品精度分析

Accuracy analysisof IMS iceand snowproducts over the Qinghai-Xizang Plateau

为了评估美国交互式多传感器冰雪制图系统(interactive multisensor snow and ice mapping system,IMS)最新发布的1km分辨率冰雪产品的精度,利用中国气象局国家气象信息中心提供的2015—2016年地面雪深观测资料对其进行验证,并分析了其与雪深、海拔的关系,结果表明:1)IMS 1km冰雪产品的总体判识准确率和无雪判识准确率全年均在80%以上,误判率在全年大部分时间都低于10%,积雪判识准确率在冬季约为60%;2)IMS 1km冰雪产品的总体判识准确率和无雪判识准确率在青藏高原大部分地区均高于85%,积雪判识准确率在青海省约50%,在西藏自治区只有约20%,误判率在青藏高原大部分地区都基本都低于10%;3)当积雪深度在1~13cm时,IMS 1km冰雪产品的积雪判识准确率随雪深的增加而增加,且相关系数达到0.91;4)随着海拔的升高积雪判识准确率总体呈下降趋势,积雪误判率呈上升趋势。总体而言,该产品在青藏高原精度一般,用于青藏高原积雪监测时仍需谨慎。

To estimate the accuracy of 1 km resolution of ice and snow products obtained from the interactive multisensor snow and ice mapping system(IMS),the ground observations of snow-depth in 2015-2016,provided by National Meteorological Information Center(NMIC),Chinese Meteorological Administration(CMA),were utilized to estimate its accuracy,as well as its connection with snow depth and altitude.Theresults showthat:1)The annually overall identification accuracy and identification accuracy of no snow of IMS products was over 80%,the annually inaccuracy is less than 10%,the identification accuracy of snow maintains60%in winter.2)The overall identification accuracy and identification accuracy of no snow of IMS products isover 85%in most parts of the Qinghai-Xizang Plateau.The identification accuracy of snow isabout 50%in Qinghai province,while 20%in the Tibet Autonomous Region.The inaccuracy of IMS products isless than 10%in most parts of the Qinghai-Xizang Plateau.3)The identification accuracy of snow of IMS products increaseswith the snow-depth when snow-depth isbelow 13cm,and the correlation coefficient is 0.91.4)The identification accuracy of snow of IMS products decreaseswith the increase of altitude,while the identification inaccuracy of snow isopposite.Generally,this product is of general precision on the Qinghai Tibet Plateau,and it is still necessary to be cautious when it is used to monitor the snow in the Qinghai Tibet Plateau.