基于多端元解混模型的博斯腾湖区域植被和水域时空变化特征及趋势分析

Spatiotemporal variation characteristics and trend analysis of vegetation and water area in the Bosten Lake based on multiple endmember spectral mixture analysis model

湿地高精度动态变化遥感监测,对于湿地保护和恢复具有重要的实践意义。以新疆博斯腾湖湿地为研究对象,运用多端元混合像元分解(Multiple endmember spectral mixture analysis,MES⁃MA)模型提取Landsat影像中植被、水体和裸地面积,通过无人机影像验证精度后,结合趋势分析法探明2000—2022年博斯腾湖湿地时空变化特征及趋势。结果表明:(1)通过无人机影像重采样精度验证的MESMA分类结果中植被像元拟合优度(R2)为0.75,水体像元R2为0.84,表明分类结果符合实际地物情况。(2)2000—2022年博斯腾湖湿地植被面积共增加536.65 km^(2),增加了183.14%;水域面积则减少595.76 km^(2),减少了37.07%;裸地面积共增加99.12 km^(2),增加了25.42%。(3)博斯腾湖湿地植被面积呈增加趋势的区域占总面积的30.6%,位于大湖区西北部和小湖区北部;反之水域面积呈减少趋势的区域占总面积的34.6%,位于大湖北岸、东岸及小湖湿地。准确掌握博斯腾湖湿地时空变化情况及其趋势,可对干旱区内陆湿地监测与保护提供参考依据。

High-precision remote sensing monitoring of dynamic changes in wetlands is of great practical significance for wetland conservation and restoration.Taking the wetland of Bosten Lake in Xinjiang as the research object,we use the multiple endmember spectral mixture analysis(MESMA)method to extract the vegetation,water body,and bare land area from Landsat images,verify the accuracy by UAV images,and then combine with the trend analysis method to explore the spatial and temporal change characteristics and trends of Bosten Lake wetland from 2000 to 2022.The results show that:(1)The MESMA classification results verified by the resampling accuracy of UAV images showed that the goodness of fit(R2)of vegetation image element is 0.75 and the R2 of water body image element R2 is 0.84,indicating that the classification results were consistent with the actual feature conditions.(2)From 2000 to 2022,the vegetation area of Bosten Lake increased by 536.65 km^(2),an increase of 183.14%;the water area decreased by 595.76 km^(2),a decrease of 37.07%;the bare land area increased by 99.12 km^(2),an increase of 25.42%.(3)The area of vegetation in the wetlands of Bosten Lake with an increasing trend accounts for 30.6%of the total area,which is located in the northwestern part of the Great Lake and the northern part of the Small Lake;on the contrary,the area of water with a decreasing trend accounts for 34.6%of the total area,which is located in the northern and eastern shores of the Great Lake and the wetlands of the Small Lake.To accurately grasp the spatial and temporal changes of Bosten Lake wetlands and their trends,it provides a reference basis for monitoring and protecting inland wetlands in the arid zone.