遥感影像中分区分类法及在新疆北部植被分类中的应用

对遥感影像提出了一种分区分类的思想，根据影像所包含的局部特征将整体影像化为几个局部的影像，然后根据局部影像的特点对图像进行分类,使得每一区域的种类数目相对于整体减少，种类的特点得以突出，分类更具有针对性,再加以高程、坡度等地貌信息，提高分类精度。该分类法在新疆北部的植被分类中得到了应用，从NOAA影像中提出的NDVI为数据源，根据该植被区域特点，将研究区的植被区域划分为四个区，即：新疆阿勒泰草原区、昭苏区、西准噶尔区和东天山区。利用GIS软件将整个研究区的NDVI指数图像化分为四块子图，根据各个区域植被的特点，采用不同的分类标准,对四块子图分类。在此之后，再利用GIS软件将所有分类子图合并为整个区域的分类图。结果表明，该类方法可以大大提高NDVI指数的植被分类精度。

Vegetation Classification Method of Divided Area and DEM at North Xinjiang

In this article, a way of dividing whole remote sensing image into subimage has leen developed to classify the type of vegetation.There are different types of vegetation in different geographic unit, so according to geographical region feature in a remote sensing image, the whole image is divided to severl subimages, the types of vegetation in a subimage is less than in a whole image. Types of vegetation in a region graphic is easy to be showed and the threshold of classifying has a wide scape. With the assistance of Digital Elevation model(DEM) and slope maps, classification accurateness was improved. This way was applied in north Xinjiang, the paper hold NDVI(Normalized Difference Vegetation Index) image as data resource, divided whole research area into four regions: Altai grassland region,West Jungger region, Zhaosu region and East Tianshan region. Different classifying standard was used in different region, and then using GIS software together four regions into a whole classified image. Because this method was grounded on knowledge, the classification result of vegetation in Xinjiang north was improved to 89.33%.