Regional Drought Vulnerability Assessment Based On Adjoint Function Of Connection Number

Drought vulnerability research is an important way to recognize the drought risk system,and has become an important topic in the field of disaster prevention,mitigation and sustainable development.Drought is an important factor affecting the economic value of regional agriculture.Further emphasis on the role of agricultural drought risk management and vulnerability assessment in disaster management is an important step for human beings to understand the natural process and live in harmony with nature.In the study of vulnerability in drought disaster system,we usually use mathematical statistics theory,connection number and its adjoint function theory and set pair analysis theory to explore the problem from qualitative analysis to quantitative analysis,and transform the abstract description of vulnerability definition into more specific digital expression and image expression,so that we can have a deeper image Understanding and analyzing drought vulnerability system.In view of this,this paper takes the regional agricultural drought vulnerability assessment as the research object,in order to analyze,reveal and measure the uncertainty relationship between the drought vulnerability assessment index value and the assessment level,in order to quantitatively assess the regional agricultural drought vulnerability,diagnose and identify the main factors affecting the vulnerability,this paper comprehensively considers the dynamic change of the difference coefficient I in the connection number formula On this basis,the physical meaning of the adjoint function of connection number is further explored,and the agricultural drought vulnerability evaluation method based on the coupling of triangular fuzzy number and connection number,and the agricultural drought vulnerability diagnosis and evaluation method based on dynamic difference coefficient I are proposed(1)In order to mine the information that the difference coefficient of connection coefficient changes with the sample value of regional agricultural drought vulnerability evaluation index in set pair analysis,a regional agricultural drought vulnerability evaluation model based on the coupling of triangular fuzzy number and connection number was established.Using triangular fuzzy number to determine the dynamic value of difference coefficient,combined with the calculation formula of quaternion connection number,the vulnerability of agricultural drought in Bengbu City from 2001 to 2010 was evaluated and analyzed.The results showed that the comprehensive evaluation method based on triangular fuzzy number and connection number coupling,the comprehensive evaluation method based on grey correlation degree and connection number coupling,cloud similarity evaluation method and fuzzy comprehensive evaluation method were the same The results are consistent.The vulnerability of Bengbu City is strong from 2001 to 2003,close to 3.5 level.The vulnerability of Bengbu City is moderate from 2004 to 2010,and fluctuates slightly around 3 level.On the whole,the vulnerability of Bengbu City is weakening.(2)In order to excavate the information that the difference coefficient of five element connection number changes with the sample value of regional agricultural drought vulnerability evaluation index,a regional agricultural drought vulnerability evaluation model based on dynamic difference coefficient was established.Based on the original data and the evaluation standard grade threshold,the piecewise functions of partial similarity difference coefficient,basic difference coefficient and partial contrast difference coefficient are constructed respectively,and the dynamic variation difference coefficient is obtained.Combined with the calculation formula of five element connection number,the agricultural drought vulnerability of Bengbu City from 2001 to 2010 is evaluated and analyzed.The results show that the comprehensive evaluation method based on dynamic difference coefficient is the same as the comprehensive evaluation method The results of the comprehensive evaluation method based on the coupling of grey correlation degree and connection number and cloud similarity evaluation method are consistent.The vulnerability is strong from 2001 to 2003,close to 3.4 level,and moderate from 2004 to 2010.On the whole,its disaster resistance ability is gradually enhanced.(3)Combined with the five-element subtraction set pair potential function method,a regional agricultural drought vulnerability diagnosis model based on dynamic difference coefficient was established.Based on the comprehensive evaluation of regional agricultural drought vulnerability,the single index connection value is used to dynamically identify the agricultural drought vulnerability index of Bengbu City from 2001 to 2010.The results show that the diagnosis method based on dynamic difference coefficient is basically consistent with the five-element subtraction set pair potential diagnosis results,and the main impact index of agricultural drought vulnerability in Bengbu City is agriculture per unit area Among them,agricultural GDP per unit area and agricultural machinery power per unit cultivated area have strong correlation with agricultural drought vulnerability in Bengbu City.To sum up,the adjoint function of connection number is of great significance for the in-depth study of agricultural drought vulnerability assessment and diagnosis.At the same time,the method has good applicability,which can provide new ideas for dealing with complex drought uncertainty problems,provide scientific basis for supporting the government's scientific prevention and control of drought risk,and provide important guarantee for the realization of regional drought mitigation strategy.