基于NPP-VIIRS数据的喜马拉雅山北坡典型湖泊湖冰提取分析

Extraction and analysis of lake ice in typical lakes on the northern slopes of the Himalayas based on NPP-VIIRS data

现阶段使用遥感数据监测湖冰物候特征已成为主要的技术手段。NPP-VIIRS是一个较新的卫星数据,它具有空间分辨率较高、波段数多、重访周期短等优点,使用该数据提取湖冰信息是对该领域的一个有益补充。基于NPP-VIIRS数据利用阈值法对拉昂错、玛旁雍错、佩枯错、普莫雍错等典型湖泊进行湖冰提取。获得四个湖泊逐日的冻结百分比,并分析了四个湖泊的冻融特征。结果表明:使用NPP-VIIRS能较好的提取湖冰信息;该地区湖泊冻融过程有风向蔓延和水流向加风向蔓延两种。气温(年负积温)是影响该地区湖冰面积最主要的因素,冻融过程主要受到风向、注入径流影响,地热资源也是影响因素之一。

Using remote sensing data to monitor the phenological characteristics of lake ice has become the main technical means.NPP-VIIRS is a relative new satellite data,which has the advantages of high spatial resolution,more band number and short revisit period.Using these data to extract lake ice information is a useful supplement to this field.Based on the NPP-VIIRS data,in this paper,the threshold method is used to extract lake ice information from typical lakes,such as La’ang Co,Mapamyum Co,Paiku Co,and Pumayum Co.The daily frozen percentages on the four lakes has been obtained,and the frozen and melted characteristics of the four lakes were analyzed.The results show that use of NPP-VIIRS can better extract the information of lake ice;the freezing and melting process of lake ice in this area has affected by wind direction and water flow.Temperature(annual negative accumulated temperature)is the main factor affecting the lake ice area in the region.The freezing and thawing process is mainly affected by wind direction and injection runoff,and geothermal resources are also one of the influence factors.