王爱芳 王妮

摘要 以三江源地区地形地貌特征、草场分布较为典型的班玛县为例，以HJ环境星多光谱影像为主要数据，基于支持向量机SVM超平面理论，结合灰度共生矩阵寻找最适宜的分类核函数，选取了三江源地区草地信息提取的最适宜SVM分类模型，并与传统的监督分类方法最大似然法和SVM分类方法进行比较，进行三江源草地分类方法的优化。结果表明，与传统监督分类方法相比，除Sigmoid核函数外，其余结合方法的分类精度均有所提高，其中结合纹理和高斯核函数的SVM分类模型有着较理想的识别效果，精度达到91%，Kappa系数为0.856 0，能为三江源地区草地可持续利用以及生态系统恢复提供基础数据。

关键词 三江源；草地信息提取；遥感；支持向量机；灰度纹理

中图分类号 S127 文献标识码 A 文章编号 0517-6611（2017）13-0210-04

Information Extraction of Sanjiang Source Grassland Based on Gray Level Texture and Support Vector Machine Classification

WANG Ai-fang1，WANG Ni1，2*

（1.School of Geographic Information and Tourism，Chuzhou University，Chuzhou，Anhui 239000；2.Anhui Center for Collaborative Innovation in Geographical Information Integration and Application， Chuzhou， Anhui 239000）

Abstract Taking Banma County with typical landform characteristics and distribution of grassland in Sanjiang Source as an example，HJ environmental satellite multispectral images were used as main data. Based on the SVM super plane theory， combined with gray level co-occurrence matrix，the most suitable classification kernel function was discussed. The optimum SVM classification model of grassland information extraction in the source region of Sanjiang was selected and compared with the traditional supervised classification methods（maximum likelihood method and SVM classification method）. The classification method of grassland in Sanjiang source was optimized. The results showed that the classification accuracy of other methods was improved compared with the traditional supervised classification method， in addition to Sigmoid kernel function. SVM classification model combined with texture and Gauss kernel function had ideal recognition effects， the accuracy was 91%， Kappa coefficient was 0.856 0. The research results can provide basic data for the sustainable utilization of grassland and the restoration of ecosystem in the source region of Sanjiang.

Key words Sanjiang Source；Extraction of grassland information；Remote sensing；Support vector machine；Gray level texture

三江源位于青海省南部，是长江、黄河、澜沧江的发源地，生态区位显著。由于独特的地理位置和气候条件，这里的生态异常敏感和脆弱，受到世界各界的关注。尤其是近十年草原生态的破坏，致使草地生产力明显下降，生态功能弱化，严重制约了当地居民的经济发展。草原生态系统是三江源地区的主体生态系统类型，草地畜牧业是三江源地区的主导产业。因此，研究三江源地区草地的现状和动态对于不断更新三江源地区草地的基本科学数据和地区草地可持续利用以及生态系统的恢复具有重要作用。

目前，现代空间信息技术特别是遥感和地理信息系统技术的发展为土地利用空间结构研究提供了新的技术手段和方法。……