扎龙湿地克钦湖富营养化状态的高光谱遥感评价

通过分析扎龙湿地克钦湖水体高光谱反射率与水质参数的相关关系,采用单波段、波段比值等算法分别选取特征波长建立水质参数的高光谱定量模型,并且结合修正营养状态指数(TSIM)和综合营养状态指数法,对水体的富营养化程度进行了监测和评价。结果表明,单波段归一化反射率对叶绿素a估测模型效果较为理想;利用高光谱一阶微分反射率,诊断各水质参数的敏感波段,建立线性模型,确定了TN、TP、SD、CODMn的敏感波段分别为733 nm、765 nm、782 nm、680 nm。单因素水质参数评价水体富营养化水平具有一定的局限性。综合考虑多个水质指标,对水质的富营养化程度进行了评价,结果显示,克钦湖水体呈现出中营养化状态,需要采取一定的措施,防范于未然。

Hyperspectral Data Applied in Monitoring and Evaluating the Water Trophic State of Keqin Lake,Zhalong Wetland

The approach of field reflectance spectra was used to monitor and evaluate the trophic state in Keqin Lake,Zhalong wetland,China,based on 30 in situ water sampling data,together with the analysis of algorithms of chlorophyll-a,SD,TP and CODMn.The field reflectance hyperspectral was measured with ASD Fieldspec spectrometer.Furthermore,with the TSIM trophic state index model,the trophic state of Keqin Lake was monitored and evaluated.The results showed thatThe single band is significantly correlated with the concentration of chlorophyll-a,it is higher than that gained with other models.On the basis of analyzing the water reflectance spectral characteristics,the sensitive wave band of water quality parameters is diagnosed with the methods of differential spectroscopy and statistical analysis,the sensitive wave bands of TN,TP,SD and CODMn are 733 nm,765 nm,782 nm,and 680 nm,respectively.To compared with multi parameter TSIM,single parameter TSIM is limited.So the assessment of trophic state was performed by multi-parameter TSIM.Keqin Lake is in mesotrophic state,and needs to be prevented from further worsen.