In analysis of how the water quality changes with the change of water quantity

firstly we adopt correlation analysis to determine the relevance between water quality and water quantity

and then build the relational model of the initial water quality and the ultimately required amount of water

finally we test the model.In the process of engineering experiment

the highlight is that how munch water is required in Changshu water control to make the water under the Wangting interchange gates reach the standard.For the water quality under Wangting interchange gates is influenced by the water along the Wangyu River

we suppose that the initial water quality is measured by the initial water in all sites

and that when the water in each site along the Wangyu River reaches the standard

the total amount of water flow through the Wangting interchange gates is the required amount

so that we can guarantee the data used to modeling is reliable.In the process of modeling

considering the influence of seasonal changes and outliers

we respectively build different models based on correlation analysis

and then by comparison

we determine the final model

which has guaranteed the accuracy of our approach.