Construction And Evaluation Of Risk Index System Of Farmland Waterlogging In Luoshan Drainage Area Of Fourlake Watershed

Waterlogging is a natural disaster that has always plagued the development of human society,and the annual reduction of food,cotton and oil accounts for about 5% [1] of the total output.The mechanism based on waterlogging index,waterlogging risk level and waterlogging evaluation have always been one of the important topics of scholars,and have important theoretical and practical significance.Based on the previous research,analyzing the waterlogging formation mechanism,combining the waterlogging risk index,the index weight assignment method and the waterlogging risk evaluation model:(1)With Luoshan Drainage Area as the object,the influencing factors of waterlogging formation(disaster-causing factors,pregnancy disaster environment,disaster-bearing body and disaster prevention capacity)were introduced one by one.Then,the correlation between the disaster-causing factors(rainfall and temperature)and flood loss was analyzed,and found that the correlation between rainfall,temperature and crop production rate,while the correlation of rainfall in flood season is more significant.The characteristics of the disaster factors and the time change of the pregnancy environment were analyzed.(2)Based on the comprehensive study of the waterlogging characteristics of the region,11 waterlogging risk indicators were reasonably selected from the influence factors to build a waterlogging risk assessment index system.Select hierarchical analysis method(AHP),CRITIC method and AHP-CRITIC comprehensive method,analyzed the correlation coefficients of the weight under the three methods,and found that both two methods have significant correlation,indicating the results of the three methods,and the results of AHPCRITIC comprehensive method can be used as the basis for subsequent calculation.(3)Combined with the weight assignment results,the waterlogging risk evaluation model was constructed,using the 1980,1996 and 2015 as the typical annual verification adaptability of the waterlogging model,and the results showed good model adaptability.Using historical disaster data,the waterlogging risk in the study area was divided into three levels: high risk,low risk and risk-free.Combined with the risk level of waterlogging,the current situation of waterlogging in Lushan drainage area is comprehensively evaluated by using the model.(4)Based on the waterlogging level under the current conditions of the research area and the change conditions of the lower pad surface under human activity intervention,the waterlogging control plan was set up by changing the drainage indicators,waterlogging stagnation water surface and water and drought ratio.It is found that in many schemes,the scheme to improve the water and drought ratio is the best ability to reduce the flood risk.In short,based on the characteristics of the waterlogging area,the paper analyzed the time changes of waterlogging influence factors,disaster factors,pregnancy environment,CRITIC,AHP-CRITIC,and flood control measures suitable for the study area.The research results can provide scientific basis for real-time monitoring and early warning of waterlogging,take targeted disaster prevention measures,and carry out risk transfer of agricultural disaster insurance,so as to reduce disaster risk and ensure the sustainable and stable development of food security and agricultural production,which has high theoretical significance and practical value.