In this paper,we have discussed deeply the research on WebGIS application in the field of water quality assessment management.

Based on representative samples,a comparative study was carried out for seven typical comprehensive water quality assessment methods including single factor assessment method,pollution index method,fuzzy method,grey system method,analytic hierarchy process method,artificial neural network method,water quality identification index method.

Projection pursuit model for comprehensive evaluation of water quality;

In the comprehensive evaluation of water quality, the results obtained by using those traditional methods for determining the weighting factors are normally quite subjective.

Considering that comprehensive evaluation of water quality involves many indexes,many classifications and interval values,variable fuzzy sets theory is applied.

A model based on genetic neural network was set up for comprehensive assessment of water quality.

Based on data of the water quality from Xincheng bridge in Lanzhou reaches of Yellow river,the authors setup a models of artificial neural networks BP networks presented for comprehensive assessment of water quality and the BP network model in which the multi unit of output employed by other researchers is substituted by single unit output .