基于Sentinel-2数据的南矶湿地面向对象决策树分类  

Object-Oriented Decision Tree Classification of the Nanji Wetland Based on Sentinel-2 Data

作　　者：庄小燕 况润元[1,2] ZHUANG Xiaoyan;KUANG Runyuan(Jiangxi Province Key Laboratory of Water Ecological Conservation in Headwater Regions,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,P.R.China;School of Civil and Surveying&Mapping Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,P.R.China)

机构地区：[1]江西理工大学河流源头水生态保护江西省重点实验室,江西赣州341000 [2]江西理工大学土木与测绘工程学院,江西赣州341000

出　　处：《湿地科学》2024年第5期630-640,共11页Wetland Science

基　　金：国家自然科学基金项目(42361055)资助。

摘　　要：鄱阳湖南矶湿地环境复杂、湿地类型多样,实现对该区湿地信息的动态监测和自动提取对于湿地生态系统的保护与管理具有重要意义。以Sentinel-2影像为数据源,辅助DEM数据和Google Earth高清影像,选取影像纯净像元作为训练样本和验证样本,根据样本的光谱特征和空间特征,构建面向对象CART(Classification And Regression Tree)决策树模型,实现南矶湿地类型分类,并研究2018—2021年南矶湿地类型的转移特征。结果表明,结合面向对象CART决策树分类方法可以得到精度较高的分类结果,总体精度可达86.36%,Kappa系数为0.83,与传统的监督分类方法相比,总体精度提高了6.29%;南矶湿地具有明显的季节性特征,春、冬季草洲分布较为广泛,夏、秋季大部分泥滩、草洲被淹没;受水位和地形影响,南矶湿地类型转移变化主要体现在水域、泥滩、草洲之间的相互转化,耕地、林地以及建筑用地分布较为稳定。与传统的监督分类方法相比,面向对象CART决策树分类结果较好,可快速、高效地实现湿地信息提取。The environment of the Nanji Wetland in the Poyang Lake is complex and the wetland types are diverse.It is of great significance to realize the dynamic monitoring and automatic extraction of wetland information for the protection of wetland ecosystem.In this study,we used the Sentinel-2 image as the data source,the DEM data and the Google Earth high-definition image as the auxiliary data,and selected the image pure pixels as the training samples and the verification samples.According to the spectral and spatial characteristics of samples,the classification and regression tree(CART)model was constructed to realize the classification of the Nanji Wetland,and to study the types transfer changes of the Nanji Wetland from 2018 to 2021.The results showed that the combination of object-oriented CART decision tree classification method could get the classification results with high accuracy.Its overall classification accuracy could reach 86.36%,with a Kappa coefficient of 0.83,while the overall accuracy of the traditional supervised classification method was only 80.07%,the Kappa coefficient was 0.76,which was an improvement of the overall accuracy of 6.29%.The wetland types in the Nanji Wetland had obvious seasonal characteristics,with the area of grassland widely distributed in spring and winter,and most of the mudflat and grassland being flooded in summer and fall.The wetland types in the Nanji Wetland were shifted and changed mainly due to the influence of the water level and the topography factors,which mainly reflect the mutual transformation between the water area,mudflat and grassland.By the influence of water level and topographic factors,the wetland types in the Nanji Wetland had been shifted mainly in the mutual transformation among water,mudflat and grassland,and the distribution of cultivated land,forest land and building land were relatively stable.Compared with the traditional classification method,the object-oriented CART decision tree classification results were better,and the wetland information extract

关 键 词：湿地信息提取 湿地分类 面向对象 CART决策树 南矶湿地 鄱阳湖 

分 类 号：X87[环境科学与工程—环境工程]