Risk Characteristics Of Regional Agricultural Waterlogging Disaster And Its Control Countermeasures

Jiansanjiang branch of Heilongjiang Beidahuang agricultural reclamation Group is located in the hinterland of Sanjiang Plain.The region is rich in water and soil resources,suitable for agricultural production,and is an indispen sable food production and Food Reserve in China.However,under the influence of the high-intensity development of agriculture,soil erosion is increasing,the yield of grain crops is unstable,the ecological environment is seriously damaged,and the risk of agricultural waterlogging disaster is increasing.In view of the above problems of agricultural waterlogging disaster in Jiansanjiang branch,this study takes 15 farms under the jurisdiction of Jiansanjiang branch as an example,establishes the evaluation index system of regional agricultural waterlogging disaster by reasonably constructing the evaluation index optimization model,calculates the risk index of agricultural waterlogging disaster by using three evaluation models,and selects the optimal model for evaluating agricultural waterlogging disaster,The evaluation of regional agricultural waterlogging disaster was completed,and the temporal and spatial evolution pattern of agricultural waterlogging disaster risk was analyzed.Identify the key driv ing factors of regional agricultural waterlogging disaster risk,and analyze the driving mechanism of regional agricultural waterlogging disaster risk.Taking the risk of agricultural waterlogging disaster as one of the constraints of planting structure,t he optimization model of regional agricultural planting structure under the risk constraint of agricultural waterlogging disaster was constructed.The frontier exploration was carried out in Jiansanjiang branch to reduce the loss of waterlogging and waterl ogging,To provide research reference and technical support for regional sustainable development.The results are as follows:(1)This paper analyzes the connotation of agricultural waterlogging disaster risk,and selects four systems including natural environment,human society,economic development and waterlogging prevention technology.Using cluster analysis and information content to optimize the screening index model,14 indexes were screened out,and the regional agricultural waterlogging disaster risk evaluation index system was constructed.The established index system can make 33% of the evaluation indexes reflect 93.6% of the evaluation indexes,and can reasonably reflect the original information of the indexes.Referring to the previou s research results,this paper compares and analyzes the differences in the establishment of index system,the selection of index and the number of index layers,and draws the conclusion that the index system constructed in this paper is more reasonable.(2)According to the established agricultural waterlogging disaster risk index evaluation system,taking the agricultural waterlogging disaster risk system of 15 farms under the jurisdiction of Heilongjiang Jiansanjiang branch in 2015 as an example,set pai r analysis model,set pair analysis based on genetic algorithm(GA-SPA)and genetic algorithm(GA-SPA)were adopted Set pair analysis(SSO-SPA)based on social spider optimization algorithm is used to analyze the risk of agricultural waterlogging disaster.By using the sum of serial numbers theory and Spearman correlation coefficient method,the three evaluation methods are sorted and the coefficients are calculated,so as to determine the stability of the model.Based on the theory of differentiation,the reliability of the risk grades of agricultural waterlogging disaster of the three evaluation methods was analyzed.Arc GIS software is used to draw the optimal model,that is,the spatial distribution map of agricultural waterlogging disaster risk of Jiansanjiang branch in 2015 under the SSO-SPA model.The results show that the probability of waterlogging disaster risk of each farm is low,and has a certain spatial distribution law.The six farms of grade I are mainly distributed in the northeast of the bran ch,and the distribution is relatively scattered.The 9 farms of grade II are mainly distributed in the middle of the branch.The overall risk level of waterlogging disaster is high in the middle and low around.In the evaluation results of SSO-SPA model,SPA model and GA-SPA model,the order of stability from high to low is: SSO-SPA model > GA-SPA model > SPA model;The discrimination of SPA model is greater than that of SSO-SPA model,but by comparing the standardized scores,we can see that SPA model has shortcomings,and the order of reliability from high to low is: SSO-SPA model > GA-SPA model > SPA model.It shows that SSO-SPA model has some advantages in the stability and reliability of regional agricultural waterlogging disaster risk assessme nt,and it is an effective method to identify the risk characteristics of agricultural waterlogging disaster.(3)Based on the regional agricultural waterlogging disaster risk optimal model SSO-SPA model,the connection degree of 15 farms under the jurisdi ction of Jiansanjiang branch in different years was calculated,and the agricultural waterlogging disaster risk level of each farm was determined according to the connection degree.Using Arc GIS software to draw the spatial distribution of agricultural waterlogging disaster risk level of each farm in different years,the risk level of agricultural waterlogging disaster in Jiansanjiang branch was analyzed.(4)Principal component analysis was used to rank the importance of the evaluation indexes of agricultural waterlogging disaster risk affecting Jiansanjiang branch.Among the key driving factors,the decisive driving factors are runoff depth,per capita green area,water surface rate,sowing area ratio,per capita GDP,gross agricultural output value per un it area,and unilateral output value of agricultural water supply.The reference driving factors are the ratio of waterlogged area to waterlogged area and per capita cultivated land area.(5)A multi-objective particle swarm optimization algorithm is propo sed to optimize the agricultural planting structure of Jiansanjiang branch.The planting area of rice,corn and soybean in each farm is taken as the decision variable,and the economic benefit,social benefit,ecological benefit and water production benefi t are taken as the objective function Crop irrigation water quantity and agricultural waterlogging disaster risk are the constraints.Through the optimization of MOPSO model,compared with 2018,the economic,social,ecological and water production benefit s of rice,corn and soybean planting areas in 2020,2025 and 2030 are significantly improved.In addition,compared with the planting structure without adding the risk of agricultural waterlogging disaster as the constraint,the agricultural planting structure is significantly limited by the risk coefficient of agricultural waterlogging disaster,and the development of agricultural production of Jiansanjiang branch should be properly considered.