摘要
盐渍土表层盐分累积与土壤含水量有着直接的关系。为了建立干旱区盐渍土含水量高光谱遥感监测模型,本文以艾比湖流域不同含水量的盐渍土为研究对象,采用光谱反射率变换和多元统计分析(MSAM)方法,对土壤含水量的光谱特征进行分析和建模。结果表明:随着土壤含水量的增加,土壤反射率呈下降趋势;在一定范围内,波长越长,土壤光谱反射率与含水量的相关性越高,其中1 937 nm处的土壤光谱反射率与含水量具有最高的相关性(r=-0.636)。对土壤光谱反射率进行8种光谱反射率变换后,在此基础上利用多元统计方法分析盐渍土的不同含水量与光谱之间的相关性,筛选敏感波段,建立关系模型。得出对数一阶微分(Logarithm First Order Differential)在波长2 024和2 357 nm建立的模型以及均方根一阶微分(Root Mean Square First Order Differential)在波长1 972和2 357 nm建立的模型最优,相关系数r分别为0.894和0.865。基于上述模型作者构建了一种耦合模型,其相关性r=0.926比对数一阶微分模型提高了0.032,比均方根一阶模型提高了0.061;因此,所构建的盐渍土含水量估算模型是可行的,可以为遥感反演提供理论参考,对高光谱遥感反演具有一定意义。
[Background] With the development of spatial information science,the hyperspectral remote sensing becomes more and more important in nowadays. Studying on spectral characteristic of soil water content is an important work,for it is the base of monitoring remote sensing. This study aims to investigate the spectral characteristic of soil water content and the relationship between the hyperspectral data and the soil water content,to explore a rapid and accurate method for estimating soil water contents,and to establish the hyperspectral remote sensing monitoring model for saline soil water in the arid area of the Ebinur Lake Watershed. [Methods] This study took saline soil with different water contents in Ebinur Lake Watershed as the research object, used the spectral reflectance transformation and multivariate statistical analysis methods（ MSAM） to analyze the spectral characteristic of soil water content,and built models. [Results]The result showed that with the increase of soil water content,thereflectance of soil declined. In a certain range,the longer the wavelength,the higher the correlation between the soil spectral reflectance and soil water content; the soil spectral reflectance at the wavelength of 1 937 nm（ r =- 0. 636） had the highest correlation with water content. After 8 transformation of soil spectral reflectance,the correlation of logarithmic first order differential sensitive band of 2 357 nm was the best（ r =- 0. 808 6）. Subsequently,MSAM were applied to analyze the correlation between spectrum and salinized soil with different water contents,then the spectral sensitive band of the soil was screened,and the correlation model was established. The result indicated that the model set up by Logarithm First Order Differential at the wavelength of 2 024 nm and 2 357 nm and the Root Mean Square First Order Differential at the wavelength of 1 972 nm and 2 357 nm was the best,the correlation coefficient r was 0. 894 and 0. 865 respectively. Based on the above established models,the authors constructed a new model,and the correlation r of which was 0. 926,increased 0. 032 against the Logarithm First Order Differential model,and increased 0. 061 compared to the Root Mean Square First Order Differential model. [Conclusions] Therefore,the estimation model of soil water content is feasible. In addition,this study provides a new model for the indoor hyperspectral estimation of soil water content in Ebinur Lake Watershed,and it also provides a theoretical and technical reference for the hyperspectral quantitative estimation of soil water content,which has certain guiding significance for hyperspectral remote sensing.
作者
张海威
张飞
李哲
井云清
ZHANG Haiwei ZHANG Fei LI Zhe JING Yunqing(College of Resources ＆ Environmental Science, Xinjiang University, 830046, Urumqi,China Key Laboratory of Oasis Ecology, 830046, Urumqi,China General Institutes of Higher Learning Key Laboratory of Smart City and Environmental Modeling, Xinjiang University, 830046,Urumqi, China)
出处
《中国水土保持科学》
CSCD
北大核心
2017年第1期8-14,共7页
Science of Soil and Water Conservation
基金
国家自然科学基金"新疆联合基金本地优秀青年人才培养专项"(U1503302)
关键词
光谱特征
含水量
模型
艾比湖流域
spectrum characteristic
water content
modeling
Ebinur Lake Watershed
