An approach to a coastal water quality index for Taiwan

The Marine Water Quality Standard issued by Taiwan EPA has disadvantages of rough classification, indistinct boundary value and numerous parameters. A Coastal Water Quality Index (CWQI) is established in this study to solve the above mentioned disadvantages and to understand coastal water quality better for the general public. Six coastal water quality experts in Taiwan were surveyed by using Delphi method to select several parameters from Marine Water Quality Standard. The fourth order polynomial regression was performed to process the surveyed data for each parameter as the scoring function. The minimum scoring method gives more diverse result for different water quality monitored sites than that of geometric weighted method. Therefore, the minimum scoring method is favored in order to distinguish the degree of the pollution. The result shows that pH, DO, BOD, cyanide, coliform, Cu, Zn, Pb, Cd, Cr are the suggested pollution parameters for CWQI.