摘要
利用野外光谱仪获取矿区农田重金属污染水稻的冠层反射光谱,通过曲线模拟和统计分析提取了与水稻冠层叶片重金属含量变化极显著相关的光谱敏感波段(Pb,460 nm;Zn,560 nm;Cu,660 nm;As,1 100 nm)、归一化植被指数(Pb,NDVI(510,810);Zn,NDVI(510,870);Cu,NDVI(660,870);As,NDVI(510,810))和"红边"位置等水稻冠层反射光谱特征。表明水稻重金属污染可以被地面遥感传感器快速检测,其浓度变化与所提取的光谱特征之间存在极显著相关,归一化植被指数与"红边"位置对光谱信息的表达要优于敏感波段。归一化植被指数以及"红边"位置可以作为水稻重金属污染遥感监测模型的光谱特征参数选择参考。同时,文章提出了利用遥感技术监测水稻重金属污染的"光谱临界值"概念,并计算出研究中各重金属对应的"光谱临界值"。
Because of frequent mining, heavy metals are brought into environment like soils, water and atmosphere, resulting heavy metal contamination in the agricultural region beside mines. Heavy metals contamination causes vegetation stress like de- struction of chloroplast structure, chlorophyll content decrease, blunt photosynthesis, etc. Spectral responses to changes in chlorophyll content and photosynthesis make it possible that remote sensing is applied in monitoring heavy metals stress on paddy plants. Field spectroradiometer was used to acquire canopy reflectance spectra of paddy plants contaminated by heavy metals re- leased from local mining. The present study was conducted to （1） investigate discrimination of canopy reflectance spectra of heavy metal polluted and normal paddy plants; （2） extract spectral characteristics of contaminated paddy plants and compare them. By means of correlation analysis, sensitive bands （SB） were firstly picked out from canopy spectra. Secondly, on the basis of these sensitive bands, normalized difference vegetation indices （NDVI） were established, and then red edge position （REP） was extracted from canopy spectra via curve fitting of inverted Gaussian model. As a result of correlation analysis, 460, 560, 660 and 1 100 nm were considered respectively as sensitive band for Pb, Zn, Cu and As concentration in paddy leaves. Further- more, heavy metal concentrations （Pb, Zn, Cu and As） were significantly correlated with NDVIs （Pb, NDVI（510, 810）;Zn, NDVI（510, 870）;Cu, NDVI（660, 870）;As, NDVI（510, 810））. Heavy metals were also significantly correlated with REP, however, the in- flexion termed as spectral critical value （SCV） between low and high heavy metals concentrations should be considered during ap- plying REP in remote sensing monitoring. Moreover, NDVI and REP are much better than SB in terms of capability of express- ing spectral information. Therefore, heavy metals contamination in paddy plants can be remotely monitored via ground s
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2010年第2期430-434,共5页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(40571130)
博士后基金项目(20080441080)资助
关键词
重金属
水稻
冠层反射
光谱特征
光谱临界值
Heavy metal
Paddy
Canopy reflectance
Spectral characteristics
Spectral critical value
