Optical Properties And Remote Sensing Inversion Of Suspended Particulate Matter In Surface Water During Flood Period In Poyang Lake

Suspended particulate matter is an important parameters in water quality assessment.As it varies greatly in temporal and spatial distribution,by means of ocean color remote sensing,suspended particulate matter would be effectively monitored and analysed to solve the problems of small-area observation and inconvenience in observation.In the text,MODIS remote sensing data is taken as data source,by monitoring the total suspended matter concentration and the change of water area in Poyang Lake area from 2002 to 2016.Then we can build up empirical model and semi-analytical model between suspended particulate matter concentration and AOPs,meanwhile to analyze spatio-temporal characteristics of suspended matter concentration.The main research results are as follows:Firstly,The remote sensing reflectance and suspended particulate matter was monitored and the optical characteristics of suspended sediment concentration in surface water from June 25,2017 to 29 during Poyang Lake flood period was analysed.Secondly,The empirical models of remote sensing reflectance and suspended particulate matter was built.With the measured 36 samples data measured in June 2017 in Poyang Lake as the experimental basis,the empirical model would be established between MODIS remote sensing reflectance and suspended particulate matter concentration.The model average absolute error is7.60mg/l,the avrelative error is 22.32%,the RMSE is 3.87mg/l.The model would be applied to MODIS images to retrieve the dynamic distribution map.Thirdly,The semi-analytical models between remote sensing reflectance and suspended particulate matter concentration was built.The model was based on the radiative transfer process of light in water and it take the inherent optical properties as mediator to build the relation between the inherent optical properties and suspended particulate matter concentration.The model average absolute error is 17.04mg/l,the avrelative error is 54.91%,the RMSE is 6.00mg/l.Compare with the empirical model and semi-analytical model,What would be concluded was that the difference in inversion precision between empirical model and semi-analytical model was small and the empirical model had a higher precision than the latter.While the IOPs was considered in the semi-analytical model,meanwhile the model had a better inversion precision and some kind of universality to some extent,it becomes a feasible method to be used in inversion.Finially,Temporal and spatial characteristic of suspended particulate matter of surface water during flood period in Poyang lake.In both the temporal and spatial dimensions,the suspended particulate matter concentration had apparent interannual and seasonal variation characteristic.In wet season in a year which rains a lot,the Suspended matter concentration was higher than normal and dry years with the wider distribution range and uniformity.Besides the fluctuation of suspended sediment concentration had a apparent increasing tendency in the main of Poyang lake.