遥感监测东北地区典型湖泊湿地变化的方法研究

Remote Sensing of Lake Wetlands Change in Northeast of China Using the Modified Detection Method

湖泊湿地生态脆弱,易受环境因子的影响。近十年来,东北地区湖泊湿地的时空格局发生了显著变化。如何简单、有效地提取湿地变化范围进而确定其变化类型是湿地变化检测中最需要解决的问题。基于2006~2016年30 m空间分辨率的Landsat-TM/OLI影像数据,水体、植被和土壤等生态因子的动态变化率被用于提取东北地区湖泊湿地变化范围;多维特征数据集的湿地分类方案确定湿地的变化类型。另外,湿地变化检测类型分为转出类型(湿地减少),转入类型(湿地增加)和湿地间转换类型(湿地相对稳定)。最终基于动态变化率计算方法,松嫩平原湿地、兴凯湖湿地和呼伦湖湖泊湿地变化结果的正检率均高于90%。同时,利用年内多时相数据和综合多维生态指数共同表征地表的状态变化,实验区的湖泊湿地分类结果的整体分类精度和Kappa系数分别达到84.31%和0.788。湖泊湿地变化检测方法具有很好的检测精度,可以代表研究区湖泊湿地类型的实际变化,是湿地资源调查与遥感监测技术研究的有益补充,为进一步深化与拓宽地表生态质量评价及其动态变化检测的方法研究提供理论基础。

Lake Wetlands have larger ecological function such as climate regulation and biodiversity,and eco⁃nomic effects-flood storage and shipping.In recent decades,the spatiotemporal variation ofLake Wetlands in Northeast China is different from the global change feature.Based on the landsat-5/8 image data with 30m spa⁃tial resolution from 2006 to 2016,thedetection method based on the Dynamic Ratio algorithm is used for extract⁃ing the change ecological information,and determining the change area of Lake Wetlands;the classification scheme based on the multidimensional-indexes is constructed to extract the change types of Lake Wetlands.In addition,the change types of Lake Wetlands are divided into the transfer-off(this is,the decrease of wet⁃lands),the transfer-in(the increase of wetlands),and the conversion of wetlands(the relatively unchanged wetlands).The finalresults showed that:from 2006 to 2016,based on the dynamic change results of the DRM method,the correct detection ratio of wetland change in Songnen Plain,Xingkai Lake and Hulun Lake are 90.48,90.2 and 93.81%,respectively.Meanwhile,the overall accuracy and Kappa coefficient of the land-cov⁃er classification results in the experimental area reached 84.31%and 0.788 respectively.The Lake Wetlands in Northeast China have the change trend characterized by the improvement feature,which can represent the actual fluctuation of wetland types in the study area.This method also has higher detection accuracy under complex surface types,which is a beneficial supplement to the resource’s investigation of Lake Wetlands and remote sensing monitoring on the wetland change.