Fractional Order Grey Seasonal Model And Its Application In Water Quality Prediction

The rapid development of economy has brought about a series of secondary environmental problems,among which the expansion of water pollution has attracted extensive attention from the public and the government.The main causes of water pollution are the uncoordinated development between economic construction and environmental protection and the over-concentration of production scale and population which exceeds the carrying capacity of local water resources.After the first stage of comprehensive water pollution control,the prevention and control of water pollution at the present stage should focus on prevention and treatment.This paper aims to provide data support for water environment monitoring and early warning in the second stage of water pollution treatment,thus consolidating the achievements of water pollution treatment at the present stage and alleviating the contradiction between economic development and water resources protection.Considering that the change of water pollution has seasonal characteristics and the change is too fast to be applied to big data modeling,a fractional-order discrete gray seasonal model is proposed in this paper.The grey prediction model has the advantage of a small number of data.After changing the parameter training rules of the grey prediction model,the cross-cycle training of the grey action in the model is carried out to generate the seasonal parameters.The fractional order discrete grey model with the addition of seasonal parameters makes up the seasonal defect of the traditional grey model.The introduction of seasonal parameters makes the new model output seasonal fluctuations.Secondly,the introduction of fractional order accumulation operator reduces the disturbance boundary of the model solution,prevents the model from unstable changes when processing seasonal fluctuation data,and effectively improves the model's ability to capture the seasonal characteristics of the original data.Finally,six main pollution indexes of surface water quality and four main pollution indexes of ground water quality in Hengshui urban area are predicted and analyzed respectively by using fractional order discrete grey prediction model.The results show that the fractional order discrete grey prediction model has a good performance in water quality prediction.It is suggested that the Hengshui municipal government should treat the water quality according to the water environmental standards.In the surface water environment,attention should be paid to the eutrophication of water body and the treatment of single water quality index.In the groundwater environment,the healthy use of drinking water should be taken into account,the emergency plan should be established to deal with sudden water pollution,and the comprehensive guarantee and emergency system of Hengshui water environment should be established and improved.