| 刘志国,周云轩,沈芳.河口水体泥沙浓度的水面光谱统计模式分析[J].水利学报,2007,38(7):799-805 |
| 河口水体泥沙浓度的水面光谱统计模式分析 |
| Statistic analysis of suspended sediment concentration in offshore waters based on field measurement of reflectance hyper spectral |
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| DOI： |
| 中文关键词: 长江口 Ⅱ类水体 悬浮泥沙浓度 高光谱 遥感 反射率测量 |
| 英文关键词: remote sensing reflectance measurement hyper spectral suspended sediment concentration case Ⅱ waters Yangtze River estuary |
| 基金项目: |
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| 中文摘要: |
| 现场测量长江口Ⅱ类水体的反射高光谱，并同步获取水样、测量流速，在实验室中对所获水样的泥沙浓度进行测定。通过对试验数据的分析发现，水体反射光谱随泥沙浓度不同而发生变化，在黄绿光波段(560～720nm)和近红外波段(810nm)出现两个明显的反射峰。波长大于650nm光谱反射率和表层泥沙浓度的相关性较好，特别在690～900nm波段两者的相关系数大于075，对泥沙浓度变化较为敏感。基于最小二乘法，建立了单波段反射率与泥沙浓度关系以及波段反射率比值与泥沙浓度关系的回归方程。结果表明，670nm和715nm处单波段反射率的指数方程相关系数较高，而基于810/690波段反射率比值的二次多项式拟合方程对泥沙浓度的预测精度好于其它比值组合形式的模型。 |
| 英文摘要: |
| Remote sensing measurement with field spectrometer was carried to acquire the reflectance hyper spectral data of the case II waters in the Yangtze River estuary. At the meantime, the surface water samples at depth of 0.5m were bottled for suspended sediment concentration measurement and analyzed in laboratory. The current velocity was also measured synchronically with the spectral measurement.It was found that the reflectance amplitudes vary with the suspended sediment concentration. Two peaks exist in yellow green (560～720nm) band and near infrared band (810nm) respectively. At wave length above 650nm a strong correlation exists between spectral reflectance and suspended sediment concentration. In the
interval of wave length from 690nm to 900nm the reflectance is sensitive to variation of sediment concentration with correlation coefficient higher than 075. Based on the least square method, the exponential relationship between spectral reflectance and sediment concentration as well as the power function relationship between spectral reflectance ratio and sediment are established. It is found that the exponential relationship for wave length at 670nm and 715nm
has higher correlation coefficient. But the quadratic polynomial relationship for spectral reflectance ratio at wave length at 810nm and 690nm has better accuracy for estimation of sediment concentration. |
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