伊犁绢蒿光谱反射率及反演精度对覆盖度变化的响应  

Response of spectral reflectance and quantitative characteristics inversion accuracy to the change in coverage of Seriphidium transiliense

作　　者：李嘉欣 王惠宁 刘文昊 靳瑰丽[1] 宫珂 韩万强 岳永寰 吴雪儿 马建 LI Jiaxin;WANG Huining;LIU Wenhao;JIN Guili;GONG Ke;HAN Wanqiang;YUE Yonghuan;WU Xueer;MA Jian(College of Grassland Science,Xinjiang Agricultural University/Xinjiang Key Laboratory of Grassland Resources and Ecology,Urumqi 830052,Xinjiang,China)

机构地区：[1]新疆农业大学草业学院/新疆草地资源与生态重点实验室,新疆乌鲁木齐830052

出　　处：《草业科学》2023年第11期2775-2786,共12页Pratacultural Science

基　　金：国家自然科学基金项目(31960360)。

摘　　要：为探究覆盖度变化对植物光谱反射率的影响,实现覆盖度和生物量的高精度反演,以伊犁绢蒿(Seriphidium transiliense)为对象,通过室内控制试验获取不同覆盖度下植物光谱反射率,采用最大归一法、一阶微分和二阶微分变换分析其反射率变化,利用归一化植被指数(NDVI)、比值植被指数(RVI)、增强型植被指数(EVI)和土壤调节型植被指数(SAVI)共4种植被指数对覆盖度与生物量进行反演,探讨反演精度对覆盖度变化的响应。结果表明:伊犁绢蒿植物种群的冠层光谱反射率在可见光波段随覆盖度增加逐渐减小,在近红外波段逐渐增加,在680 nm处形成植物特有的红边效应,最大归一化和微分变换突出了植物的光谱特征;光谱反射率差值在可见光波段随覆盖度增加基本稳定;利用植被指数逐级反演覆盖度与生物量时,精度随覆盖度增加整体呈上升趋势;利用土地利用/覆盖变化(LUCC)分覆盖度反演时,提高了覆盖度大于20%的伊犁绢蒿种群的数量特征反演精度,且最佳指数为SAVI。The aim of this study was to explore the influence of the change in coverage on plant spectral reflectance and achieve high-precision inversion of coverage and biomass,taking Seriphidium transiliense as the object.We obtained the spectral reflectance of plants under different coverages through indoor controlled experiments;processed the data using maximum normalization;used first-order differential and second-order differential processing to analyze the changes in reflectivity;and the normalized difference vegetation index(NDVI),ration vegetation index(RVI),enhanced vegetation index(EVI),and soil-adjusted vegetation index(SAVI)were used to invert the coverage and biomass data.The response of inversion accuracy to coverage variation is discussed.The results showed that the spectral reflectance of the canopy of S.transiliense gradually decreased with the increase in coverage in the visible band and gradually increased in the near-infrared band.A characteristic plant red edge effect was formed at 680 nm,and the maximum normalization and differential transformation highlighted the spectral characteristics of the plants.The spectral reflectance difference was basically stable with an increase in coverage in the visible band.When the vegetation index was used to invert coverage and biomass step by step,the accuracy increased with increased coverage.When the land use and land coverage changed the coverage inversion,the inversion accuracy of the quantitative characteristics of the S.transiliense population with a coverage greater than 20% was improved,and the best vegetation index was SAVI.

关 键 词：伊犁绢蒿 高光谱 反射率 覆盖度 生物量 植被指数 反演 

分 类 号：S812[农业科学—草业科学]