Water quality assessment indexes are classified into the optimal minimum indexes and maximum optimal indexes for comprehensive assessments of water quality and the set pair analysis (SPA) theory is used in water quality comprehensive assessments for constructing the six-element connection number between the evaluation samples and the evaluation indexes.Because the coefficient of difference degree (CDD) of variation is difficult to calculate in conventional models,quintile interpolation algorithm(QIA) is proposed to calculate the CDD,and the calculation models with corresponding difference degree of variation coefficients are proposed;then the algorithm for calculating the SPA connection number is given.Finally,a universal comprehensive water quality assessment model based on SPA is proposed.The new model is a generic scheme that can be used to assess the quality of water on the earth surface or underground.The experiment shows that the result calculated by the model is reasonable.
Assessment of water quality Set pair analysis Coefficient of difference degrees Connection number Universal model
Zhongrong Zhang Haowen Yan Guanglu Hu Xinghong Shi Baisen Wang Wei Li
School of Mathematics&Physics Lanzhou Jiaotong University Lanzhou 730070, China;School of Mathematic Faculty of Geomatics Lanzhou Jiaotong University Lanzhou 730070, China;Faculty of Geomatics Lanzhou School of Mathematics&Physics Lanzhou Jiaotong University Lanzhou 730070, China;School of Mathematic School of Environmental and Municipal Engieering Lanzhou Jiaotong University Lanzhou 730070, China Department of Water Resources Planning Water Conservancy Bureau of Gansu Lanzhou 730070, China