Study Of Nutrient Concentration Retrievals In Qinhuangdao Coastal Area Based On MODIS Images

Nutrient is one of the important chemical characterizations of seawater quality indicators. The nutrient monitoring has a great significance to the protecting of marine environment. China`s comprehensive national power and people`s living standard have improved greatly along with several decades of economic development. But the environmental problems that cannot be ignored have hindered economic development and affected people`s daily lives. As results of industrial waste water in coastal areas and coastal sewage runoff carries a lot of pollutants into the sea, the phenomenon of the water quality deterioration and the ecological disasters appear frequently in offshore area. The traditional method of seawater quality monitoring faces challenges. It costs a lot of manpower and material resources and financial resources to do the traditional fixed sampling monitoring, and the scale, scope and frequency of it are very limited. The characteristic of remote sensing large which has area synchronized observation and strong timeliness, makes up for the deficiency of the conventional monitoring method. The use of remote sensing monitoring and timely grasp the changing water quality is the basis of objective evaluation of water quality and scientific management.In this paper, Qinhuangdao coastal area is chosen as the study area. Measured nutrient data, spectral data of six voyages in Jul, Aug 2014 and the same period data of MODIS L1 B images are selected as the study data. Single band or band combinations with higher correlation coefficient are picked out as the characteristic factors through the Pearson correlation analysis. Linear regression analysis method is adopted to establish the characteristic factor and the nutrient concentration retrieval model based on MODIS images. And the best remote sensing inversion model of each nutrient is determined through the study of the accuracy of the established model comparison and analysis. The inversion results of the nutrient concentration in Qinhuangdao coastal waters are calculated by using MODIS images with the retrieval model. The inversion results can reflect the real distribution of the nutrient concentration in the area, achieve the goal of monitoring nutrient distribution of Qinhuangdao coastal water by using MODIS images and reduce the monitoring cost. Monitoring by using it can provide the reference to evaluate the water quality in this area. At the same time, it provides reference to subsequent studies.