Risk Assessment Of Ice Disaster In The Yellow River Based On Grey Information Decisionin

The gray evaluation model is an important part of the evaluation model.In this paper,several grey evaluation model has conducted,and then applying it to solve the problem of the Yellow River ice flood disaster risk assessment whose information with grey characteristics,The main results are as follows:First of all,for ice plugs frequently appearing in the ice-drift and early freeze periods we conduct a risk assessment of the vulnerability.Considering psychological behaviors of the decision makers and the grey characteristics of the hydrology information of the Yellow River a grey relational decision method based on regret theory was proposed and this method was applied to risk assessment of ice disaster in the Yellow River reach of Bayangole,Sanhuhekou,Toudaoguai.The surprise-regret value function was defined and the surprise-regret values of the three reaches are built.The optimization models based on the surprise-regret value maximum principle were built and the attribute weights were obtained.The three reaches were sequenced according to the surprise-regret value size.The result shows that the reach of Sanhuhekou easilier occurs ice jam than the reach of Bayangole and Toudaoguai.Secondly,for the flooding of Bayangaole Station of the Yellow River we conduct a risk analysis for a decade of flood risk.For the questions of Ling-flood in the Bayangaole Station of the Yellow River,Based on the formation mechanism of ice formation,the risk evaluation standard of the flood season is established by the composition of temperature,flow and water level.With gray clustering methods and analytical techniques,a Two-stage Clustering Evaluation Model of Gray Whitening Weight Function is established;The temperature,flow and water level data of the Bayan Gaole section of the Yellow River in 2006-2006 were selected for cluster analysis,and a reasonable risk assessment was made based on the clustering results.The results show that the annual risk level of the flood season which has a number of days around 2/3 per year is distributed at medium and higher level;Interms of the overall annual risk,there are three years of high risk in the last decade and a moderate risk for seven years;The distribution of annual risk time is trapezoidal.the risk of ice-drift period is low and the risk of early freeze periods is high.the risk of open period is lower.Finally,the dynamic risk assessment analysis of the open period of the ice dam are conducted.In this paper,the data of Shizuishan section,Bayan Golay section and Sanhuhekou section of 2004-2016 in the Yellow River are selected which divided into three stages and we construct a dynamic risk type gray target model.Firstly,Based on the method of combination of regret theory and mathematical expectation we build a collection of joy-regret value.We turn the risk assessment problem into a risk assessment problem and transform the dynamicassessment problem into a static assessment problem based on the higher data reference value.The elliptical gray target model is introduced to calculate the deviation of the target from each other and the rank of each section is sorted to determine the risk level.The results show that the risk of Bayan Golay section in the Yellow River is the highest in the opening-river period,Sanhuhekou section and Shizuishan section in the Yellow River followed by the Bayan Golay section in the Yellow River.This paper constructs a variety of gray evaluation models for making a multi-faceted studies on the ice disaster of Yellow River.The reasonable evaluation results confirm the scientificity and practicability of the model and provide reference for the prevention and control of the ice disaster of Yellow River.