摘要
积雪是冰冻圈重要的组成部分,积雪面积在地表的积累和消融影响着水资源的平衡以及生态环境的变化,进而影响社会经济的发展。目前由日本宇航局发布的JASMES系列产品包含一套北半球自1978年以来长时间序列的AVHRR逐日积雪范围产品,可以作为气候和水文模型的重要输入,然而该产品在中国地区的精度尚未被评估。以高分辨率Landsat-5TM数据和气象台站雪深观测数据两种手段通过构建误差矩阵和一致性检验方法来评价JASMES积雪范围产品在我国三大积雪区(北疆,东北和青藏高原)的总体精度。研究结果表明:使用Landsat-5TM积雪面积二值图进行验证时,东北、北疆和青藏高原地区的总体精度分别为66.3%、69.3%和49.5%,积雪识别的漏分误差均较为严重,混合像元以及积雪消融时间过短严重地降低了青藏高原地区的总体评估精度;在积雪季逐月分析中,JASMES积雪产品由于地形的影响,青藏高原地区总体评估精度低于北疆和东北地区,消融过快的特性进一步降低了评估的总体精度。结合气象站点数据验证时,当雪深阈值为9cm时,青藏高原、北疆和东北地区总体精度分别为94.2%、67.8%和77.8%,青藏高原地区对非雪像元的识别精度达到98.9%;随着站点积雪覆盖日数的增加,其总体精度均呈下降的趋势,漏分积雪情况较为严重,存在多分陆地,少分积雪的现象。综上所述,JASMES积雪产品在青藏高原、北疆和东北地区均存在漏分积雪比较严重的现象,青藏高原地区积雪漏分现象最为突出。
Snow cover is an important part of the cryosphere.The accumulation and melting of snow cover on the surface of the earth affects the balance of water resources and the change of ecological environment,which further affects the development of social economy.Remote sensing is the most effective method to monitor the snow cover area.Currently,JASMES series released by the Japan Aerospace Exploration Agency contains a set of AVHRR daily snow cover products of the northern hemisphere for a long time since 1978,which can be used as an important input to climate and hydrological models.However,the accuracy of this product in China has not been evaluated.In this study,high resolution landsat|5 TM data and snow depth observation data of meteorological stations were used to evaluate the overall accuracy of JASMES snow cover products in three snow cover areas (North Xinjiang,Northeast China and Qinghai|Tibet plateau) in China by constructing error matrix and consistency test method.The results show that using Landsat 5 TM snow area of binary chart for validation,the overall accuracy of the Northeast China,North Xinjiang and the Qinghai|Tibet plateau region are 66.33%,69.27% and 66.33% respectively,the omission errors of snow are high.The mixed image elements and the short time of snow cover ablation seriously reduce the overall accuracy in Qinghai|Tibet plateau.In the analysis of snow cover season by month,the overall accuracy of JASMES snow cover products in Qinghai|Tibet plateau is lower than that of Northern Xinjiang and Northeast China due to the influence of topography,and the characteristics of rapid melting further reduce the overall accuracy of the assessment.Combined with meteorological station data validation,the overall accuracy of the Qinghai|Tibet plateau,Northern Xinjiang and Northeast China was 91.2%,59.0% and 72.5%,respectively.As the number of stations’ snow cover days increases,its overall accuracy tends to decline,and the Kappa coefficient is at a low value.The leakage error of snow cover identification is serious,and there is a phenomenon of more land and less snow cover.To sum up,JASMES snow products have serious snow leakage in the Qinghai-Tibet plateau,Northern Xinjiang and Northeast China,and the snow leakage in the Qinghai-Tibet plateau is the most prominent.
作者
王轩
郝晓华
王建
车涛
李弘毅
邵东航
Wang Xuan;Hao Xiaohua;Wang Jian;Che Tao;Li Hongyi;Shao Donghang(Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences, Lanzhou 730000,China;University of Chinese Academy of Sciences ,Beijing 100049,China;Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application,Nanjing 210023 ,China;University of Electronic Science and Technology of China,Chengdu 611731,China)
出处
《遥感技术与应用》
CSCD
北大核心
2018年第6期994-1003,共10页
Remote Sensing Technology and Application
基金
国家自然科学基金项目(41471291
91547210)
科技基础资源调查专项(2017FY100502)资助
