河流悬沙浓度的地面遥感预测方法初步研究——以金沙江下游支流为例

Preliminary Study on Estimation of Suspended Sediment Concentration in Rivers with in-Situ Remote Sensing Technique——an Example from the Lower Jinsha Tributary

以金沙江中下游一级支流龙川江为例,通过探讨河流地面反射光谱与河流悬沙浓度的关系,初步开发了河流悬沙浓度的地面遥感预测技术.研究发现,基于R800/R550的经验模型,仅能够预测浓度范围在400 g/m3以下的悬沙浓度值,对于较低悬沙浓度的河流或其他水域有较大运用价值.光学拟合技术能够预测龙川江在其整个变化范围的河流悬沙浓度,最高预测浓度可以达到13 000 g/m3.通过直接运用两种方法,或者进一步将它们提升成为卫星遥感运用技术后,对于中国西南众多的江河湖库有着重要的理论和现实意义.

Taking one of the lower Jinsha tributaries Longchuan River for example, the relation between reflectance spectra and suspended sediment concentration of river water is discussed in this paper. Ground remote sensing techniques for estimating suspended sediment concentration is preliminarily developed. It is shown that the experience model, based on the ratio of reflectance at 800 nm and 500 nm wavelength bands, can only forecast the water with the suspended sediment concentration below 400 g/m^3. It can be used in the rivers with lower sediment concentration. The spectral optical model can forecast suspended sediment concentration of Longchuan River in its whole range, and the highest forecast concentration can reach 1300 g/m^3. Througn the two methods, or improing them to be satellite remote sensing technique, the important theory and practical significance are given for the rivers and lakes in the southwest of China.