Reserach On Water Quality Dynamic Evaluation And Environment Capcity Method Of Offshore Area

There are many resources in offshore area,but poor water quality has been to disturb economic development.This paper research offshore area environment by focus in water quality evaluation and Water environmental capacity,major results as follows:(1) Membership degree can reflect the water quality level fuzzy in fuzzy set theory, but the traditional of variable fuzzy sets using subjective method to determine index weight, in this paper combined with ahp and entropy weight method to determine the weighting, To avoid the subjectivity in weight.(2)Now water environment capacity calculation needs a lot of parameters, so that we have to do a lot of experiments, This is difficult for some areas, this paper carried to the GIS interpolation function interpolation on the water quality and water depth, then calculation the water environmental capacity by choose control standards.(3) The evaluation results shows that the research offshore area water quality was good in the mass,which was between the one kind of water and the third.From point of time,we found11year is bad to09years; From point of space,we found seaside water quality is bad to high sea,and the major pollutants is Inorganic nitrogen, dissolved oxygen. chemical oxygen demand, the most unfavorable time is May2011.(4) The water environmental capacity calculation results evaluation results shows that the chemical oxygen demand (cod) of water environmental capacity is930t,2341t,2508t in three method; Inorganic nitrogen in the water environment capacity of-1470-t,305t,4191in three method, the Soluble phosphate in the water environmental capacity of3.3t, and t,30.41, in three method.Water quality assessment and water environmental capacity of natural waters involving multiple aspects, such as hydrology, water quality, humanities, economic, is a complicated system engineering, on the index mechanism of internal relations, selection of non-uniform coefficient, diffusion convection coupling of model still exist some problems to be further perfected.