基于二次散射的水污染遥感模型及其在珠江口水域的应用

Model for water pollution remote sensing based on double scattering and its application on the Zhujiang River Estuary

根据水中悬浮物、污染物和水分子等的散射和吸收物理机制建模是实现水污染定量遥感的有效途径.基于一次散射的水污染遥感模型简单易行,但在浑浊度较大时其精度不高.在基于一次散射模型的基础上分析了多次散射的能量组成特点,提出再考虑二次散射可使模型的精度显著提高且不至于使模型过于复杂;导出了二次散射的补偿因子,同时给出了考虑二次散射因子的简单计算方法.将该模型应用于珠江口水域的水污染遥感的结果表明,较之基于一次散射的模型,考虑二次散射的水污染遥感模型在精度上有明显改进.遥感提取结果显示,珠江口水域重污染区主要分布在伶仃洋东北部,香港维多利亚港和深圳湾.

It is a valid route for quantitatively remote sensing on water pollution to build model according to the physical mechanisms of scattering and absorption of suspended substance,pollutant and molecules of water. Remote sensing model for water pollution based on single scattering is simple and easy to be used,but the precision is affected by the turbidity of water. The characteristics of the energy composition of multiple scattering are analyzed, and it is proposed that, based on the model of single scattering, if the flux of the second scattering is considered additionally, the precision of the model will be remarkably raised, and the calculation is still very simple. The factor of the second scattering is deduced to build a double scattering model,and the practical arithmetic for the calculation of the model is put forward. The result of applying this model on the water area around the Zhujiang River Estuary shows that the precison of the model basing on double scattering is obviously improved. The result also shows that the seriously polluted water area was distributed on the north of Lingding Sea, the Victoria Bay of Hong Kong and the Shenzhen Bay.