单 位：
兰州大学草地农业科技学院草地农业生态系统国家重点实验室
关键词：
MOD09GA;CIVCO模型;地形校正;积雪制图
摘 要：
积雪是地表覆盖的重要组成部分和最活跃的自然要素之一,也是影响气候变化的重要因子。青藏高原作为我国稳定的季节性积雪分布区之一,准确估计其积雪覆盖面积具有重要的水文、气候和经济意义。本研究以青藏高原为研究区,针对MODIS(Moderate Resolution Imaging Spectyroradiometer)积雪产品中因受山体阴影处遮蔽而存在低估积雪覆盖面积的现象,以Landsat5-TM数据作为"真值"参考影像,利用MODIS标准积雪产品MOD10A1和地表反射率产品MOD09GA,结合CIVCO地形校正模型,通过改进MODIS积雪产品的积雪提取算法,获取具有较高积雪识别率的山区积雪图像。结果表明,CIVCO模型校正后提取的积雪图,总体分类精度为86.46%,积雪分类精度为73.66%,Kappa系数为0.61,优于MODIS标准积雪产品MOD10A1,可见,通过CIVCO地形校正模型的算法改进不仅有效地提高了山体阴影处的积雪识别精度,同时降低了由于漏测所引起的误差。因此,改进后的山区积雪图像提取算法更适合我国青藏高原地区的积雪识别,对青藏高原的积雪监测研究具有重要的应用价值。
译 名：
Validation test of the CIVCO topographic correction model on snow mapping algorithm in Tibetan Plateau
作 者：
CHEN Meng-die;HUANG Xiao-dong;WANG Wei;LIANG Tian-gang;State Key Laboratory of Grassland Agro-ecology System,College of Pastoral Agriculture Science and Technology,Lanzhou University;
关键词：
MOD09GA;;CIVCO model;;topographic correction;;snow mapping
摘 要：
Snow cover is an important part and one of the most active natural elements of the earth surface as well as an important factor affecting climate.As one of seasonal snow area in China,estimating the snow cover of the Tibet Plateau accurately has a great significance on hydrology,climate and economic. The MODIS/Terra daily snow product(MOD10A1)would underestimate snow cover area because of shade during mapping snow cover in mountainous regions over the Tibetan Plateau.To achieve snow cover image in mountainous regions with higher algorithm,the present study used Landsat 30 m observations as "ground truth"and MODIS data(MOD10A1and MOD09GA)as data sources to improve the method of snow mapping by topographic correcting based on CIVCO.The results showed that,the overall accuracy, snow classification accuracy,Kappa coefficient of the improved method were 86.46%,73.66%and 0.61, while MOD10A1were 85.69%、65.35%and 0.57,respectively.Therefore,the algorithm of the improved method were higher than the method of MOD10A1,meanwhile,the missed error of the improved method were much lower than MOD10A1,which indicated the improved method based on CIVCO topographic correction model were more capable of the alpine snow cover mapping and dynamic monitoring in Tibetan Plateau.
