Study on the Development of Water Quality Assessment

Throughout the development process of the water quality evaluation method, the paper outlines several water quality evaluation methods, summarizes them and points out the advantages and disadvantages.Finally the paper points out that water quality evaluation method will be further improved with the wide application of computer technology combined with various subjects of mutual cross-penetration.Water quality assessment evaluates qualitatively or quantitatively the water quality elements on some water environment monitoring data and in accordance with the evaluation criteria and evaluation methods.The water quality assessment is the basis for the calculation of the capacity of the water environment and water resources planning and management.It is also a prerequisite for the water control planning.Water quality assessment results can determine the water quality model and provide parameters and information for model identification and parameter identification [1].It can accurately reflect the water quality situation, understand and master the water pollution impact and development trends and provide a scientific basis for the protection of the water environment and water resources planning and management.Water quality assessment is not only the water quality of the scientific description of reality, but also points out the objectives and direction for water pollution control programs.We can build the appropriate water quality model for water pollution control programs by the information provided by the water quality assessment.In the 1960s, Jacobs proposed the water quality index of concepts and formulas of the water quality evaluation.Because it is simple and easy to operate, until today people still use it in the domestic water quality evaluation practice.Later, water quality experts at home and abroad also raised various comprehensive water quality index methods.Which the Nemerow mode, mean square error mode[2] and vector mode[3] are more typical.Since the 1980s, Some uncertainty, the emergence of the nonlinear theory method and the promotion and application of computer technology provides a theoretical basis and technical support for the new model of water quality assessment [4].Some of the commonly used methods can be summarized into the following categories throughout the development process of the water quality evaluation method.