CG-LTDR卫星气候数据集及其在中亚地区的应用

CG-LTDR Satellite-based Climate Dataset and Its Application in the Central Asia

全球及中国区域长时间序列卫星数据集(CG-LTDR)包括地表反照率、叶面积指数、土地覆盖分类、植被指数和积雪覆盖产品。为了应用CG-LTDR和其他卫星气候数据,基于WEBGIS技术建立了CG-LTDR系统,实现对卫星气候数据集的在线管理和显示分析功能。本文介绍了CG-LTDR卫星气候数据集及显示分析系统,并利用NDVI数据对中亚及周边核心区的植被状况和长期变化进行分析。结果表明:哈萨克斯坦、吉尔吉斯斯坦和塔吉克斯坦地区及新疆西部和北部植被平均状况较好。中亚地区的植被在20世纪90年代和2000年代整体状况较好,20世纪80年代相对较差,2010年后空间变化不均。特别是从21世纪开始我国西部沙漠化程度加重,一些地区地表植被严重破坏,生态环境变化不容乐观。由于中亚地区常规观测少,利用CG-LTDR卫星气候数据集对中亚地区进行应用具有很好的意义,CG-LTDR可以为农牧资源和生态环境提供有效信息。

CG-LTDR(China and Global long-term data records)are satellite climate datasets of land surface products which include surface albedo,Leaf area index(LAI),land cover classification,Normal difference vegetation index(NDVI)and snow cover product.In addition,the CG-LTDR system is an online platform based on WEBGIS technology,which is built for applications of CGLTDR and other satellite-based climate datasets.And,this system can fulfill multi-function purpose of management,visualization and analysis for satellite data records.In this paper,CG-LTDR and system are introduced to users for application,and the example of how the system is used to analyze vegetation variations in the central Asia and surrounding area based on NDVI is described.The results show that vegetation climatological conditions in the Kazakhstan,Kyrgyzstan,Tajikistan and the North and West of Xinjiang province are better than the other places of the Central Asia.As for the vegetation changes,the condition in the Central Asia has below climatological average in1980s,while it was above climatological average in1990s and2000s,and after2010year,vegetation changes became very nonuniform in space.It is not neglected that the change in ecological environmental was not optimistic,in particular,desertification has been aggravating and vegetation in some regions has been severely destroyed in Western China from the beginning of21st century.Therefore,due to lack of the conventional observations,application of CG-LTDR satellite data can play important role in the Central Asia.It is proved that CG-LTDR can provide useful information of agriculture and animal husbandry and resources,as well as ecological environment.