A Comparative Study of USA and Canadian Water Quality Index Models

摘要: The US-based water quality index models originated from the National Sanitation Foundation (NSF) in additive (AWQI) and multiplicative (MWQI) forms early 1970s. other model which has gained popularity recent years is Oregon Water Quality Index (OWQI) based on harmonic averaging concept. Canadian Council of Ministers Environment (CCME WQI) (also referred to as Index, CWQI text) was commissioned 2001 assess surface waters across Canada. United Nations Environmental Program (UNEP) endorsed CCME WQI (or CWQI) suitable for grading drinking world wide. scores all range 0 100, higher alluding better quality. categorized five grades [excellent, good, fair, marginal, poor], with differential system ranking while using score values. present study evaluated data 30 river sites province Ontario, Canada 5-year period 2002–04 through 2006–08 (3-year running averages) comparison aforementioned models. parameters currently used calculating Ontario are: ammonia, chloride, nitrate, phosphate, chromium, nickel, zinc (seven parameters). hardness, pH temperature are monitored but modifying parameters, i.e., they taken into consideration by guidelines or objective functions some former seven parameters. indicated that AWQI MWQI tended be much scores. As a result, turned out superior relation CWQI. In contrast, correspondence terms between OWQI closer better. Overall, formulation appeared most stringent, followed grade aquatic uses.