Publications

Gong Zhao-Ning; Lin Chuan; Zhao Wen-Ji; Cui Tian-Xiang (2014). Canopy water content estimation for typical emerged plant community using WorldView-2 imagery : A case study in Wild Duck Lake wetland, Beijing. JOURNAL OF INFRARED AND MILLIMETER WAVES, 33(5), 533-545.

Abstract
Quantitative estimation of emerged plant water content with multi-spectral remote sensing technique is of great significance for emerged plant physiological status and growth trend monitoring. The hyperspectral reflectance of canopy of wetland typical emerged plant(reed and cattail) was measured by Field-Spec 3 wild high-spectrum radiometer. The leaf water content and leaf area index(LAI) of corresponding samples were also measured. First of all, the ground spectral data(reed and cattail) were resampled to simulate the spectral of WorldView-2 imagery, then the simple ratio vegetation index(SR) and normalized difference vegetation index(NDVI) were constructed with arbitrary two band combination from the simulated WorldView-2 spectra, respectively. The correlation between canopy water content(CWC) and vegetation index were analyzed. The estimation models were obtained by using regression and correlation analysis for different emerged plant community. In addition, the research result of ground data was applied to WorldView-2 high resolution multispectral imagery covering the study area, and the CWC of emerged plant community was estimation in spatial scale. The results show that the SR and NDVI constructed by the simulated WorldView-2 spectra had a good overall correlation with CWC. The SR (8, 3) (reed) was selected as the optimal vegetation index to estimate the CWCreed the best models are evaluated and validated as y = 0. 005x +0. 003. The NDVI(8, 3) (cattail) was selected as the optimal vegetation index to estimate the CWCcattail, the best models were evaluated and validated as y = 2. 461x(2) -0.313x +0. 032. According to two K-fold cross validation examination, these estimation models have the satisfactory prediction accuracy. The prediction accuracy of CWCreed was 87. 42% and the prediction accuracy of CWCcattail was 82. 12%. Furthermore, based on the research result of ground data, we made use of WorldView-2 high resolution multispectral imagery to map the CWC of different emerged plant community. According to the examination of measured data, the estimation RMSE of CWCreed and CWCcattail from imagery were 0.0048 and 0. 0052, respectively. The estimation accuracy were 83. 56% and 80. 31%, respectively. It was demonstrated that using WorldView-2 high resolution multispectral imagery to estimate the CWC of wetland emerged plant community has a high feasibility.

DOI:
10.3724/SP.J.1010.2014.00533

ISSN:
1001-9014