基于被动微波遥感的青藏高原雪深反演及其结果评价  

The Retrieval of Snow Depth in Qinghai-Xizang (Tibet) Plateau from Passive Microwave Remote Sensing Data and Its Results Assessment

作　　者：柏延臣[1] 冯学智[2] 李新[3] 陈贤章[3] 

机构地区：[1]中国科学院地理科学与资源研究所,北京100101 [2]南京大学城市与资源学系,南京210093 [3]中国科学院寒区旱区环境与工程研究所,兰州730000

出　　处：《遥感学报》2001年第3期161-165,共5页NATIONAL REMOTE SENSING BULLETIN

基　　金：国家自然科学基金!项目"青藏高原积雪和冻土的微波遥感监测研究"(499710 60 );"我国积雪遥感综合定量分析系统研究!(494710 5 8)资助

摘　　要：采用修正的张氏雪深反演算法 ,用SSM/I 37GHz和 19GHz水平极化亮温值计算了青藏高原及其毗邻地区的积雪深度 ,对其精度进行了评价 ,并对误差来源进行了分析。结果显示 ,此算法能够较好地反映研究区的雪深分布 ,但局部地区误差较大 ,总体上雪深被高估。其误差主要来源于冻土 ,深霜层 ,植被以及雪层中液态水含量 ,雪粒的形状和粒径的变化带来的影响。SSM/I数据较低的分辨率和研究区复杂的地形使反演的雪深与观测的雪深缺少可比性 。Snow cover extension and snow depth information may be useful indicators of regional and global climate change and of basin_scale water storage in mountainous areas as well as snow disaster monitoring, forecasting and the loss assessment in pastoral areas. Thus, it is important to ensure that they are accurate and as free as possible of any known biases.\;Though it is practical to get snow extension from the visible and infrared remotely sensed data such as NOAA_AVHRR, TM and the like, it is nearly impossible to get snow depth information from such data set. Passive microwave remotely sensed data such as SMMR and SSM/I make it possible to derive snow depth in a large_scale area. Some algorithms have been developed to retrieve the snow depth from SMMR and SSM/I data, but those algorithms didn't perform well in many studies.\;In this paper, using a revised Chang's algorithm and SSM/I 37GHz and 19GHz horizontally polarized brightness temperature, we retrieved the snow depth distribution in Qinghai_Xizang (Tibet) plateau, assessed the results' accuracy, and analyzed their error sources. It showed that the revised Chang's algorithm described the general trend of snow depth of this area, in spite of overestimation in whole and large errors in local areas. The errors are mainly from the effects of the existence of frozen ground, depth_hoar, vegetation cover and the lacking of considering the effects of the liquid water content of snow and the changing of shape and grain size of snow. The coarse spatial resolution of SSM/I remotely sensed data makes the retrieved snow depth hard to compare with the ones from ground observation, thus, makes it difficult to \{evaluate\} the accuracy. Some suggestions for further investigation were put forward at last.

关 键 词：积雪深度 被动微波遥感 SSM/I数据 评价 青藏高原 高温数据 

分 类 号：P426.635[天文地球—大气科学及气象学] TP721.1[自动化与计算机技术—检测技术与自动化装置]