Total Water Quality Index using weighting factors and standardized into a parameter

The aim of this paper is to present a new approach to assessing water quality by using a new index: "Total Water Quality Index" ("TWQI"). TWQI Method has advantages over other methods in evaluating water quality and has been applied in Belgium, the United States of America ("WQI") and Canada ("CWQI"). In the TWQI Method, the weighting factors ("Wi") were calculated, taking into account the toxic levels of each parameter and the hierarchical tables of water quality depended on the sum of number of parameters surveyed (2≤n≤100) were all calculated by theoretical formulae, and not predefined as in other methods. The results of using TWQI in assessing coastal waters (13 parameters) are consistent with the actual data monitored.