基于WGA算子—熵权法的农业洪涝灾害风险评估——以潍坊市为例

RISK ASSESSMENT OF AGRICULTURAL FLOOD DISASTER BASED ON WGA OPERATOR-ENTROPY WEIGHT METHOD*

关键词:  农业洪涝灾害  熵权法  灵敏度分析  WGA算子  GIS

Key words:  agriculture flood disaster  entropy weight method  sensitivity analysis  WGA operator  GIS

摘要:

目的 为了提高农村地区洪涝灾害科学应对水平，减轻农业损失，构建了农业洪涝灾害风险评估模型，分析评估指标的灵敏度，制定科学有效的风险应对策略。方法 文章结合2018年山东潍坊市的气象、地理和社会经济资料，构建农业洪涝灾害风险评估指标体系，利用熵权法确定各指标的权重，通过WGA算子分析指标的灵敏度，并得到潍坊市风险评估值，借助GIS绘制潍坊市农业洪涝灾害风险等级图，以此为基础制定风险防范措施。结果 （1）地形高程差和河网密度的指标灵敏度最大，最大日降水量次之，暴雨频率、汛期降水量、地均农业GDP、卫生机构数量的指标灵敏程度低。（2）潍坊市致灾因子的危险性从西往东逐渐减弱；孕灾环境敏感度最强的是潍坊西部和南部的山区，地势起伏大、河流众多，极易造成洪涝灾害；潍坊市的承灾体易损性呈现出从西北到东南逐级递减的现象；防灾减灾能力较弱的地区位于潍坊市的中部。（3）潍坊市综合风险总体态势是从西南到东北逐级递减。（4）应对致灾危险，提高气象预警的及时性和准确性，适当调整农作物的播种时间；应对孕灾敏感，兴修水利工程，发展林业；应对承灾易损，注重抗涝作物的栽培，加强对农业的自救；增强防灾能力，推行相应的保险协议，科普相关的防灾减灾知识，从而减少洪涝灾害给农业带来的损失。结论 通过农业洪涝灾害风险评估模型，可掌握潍坊市各地区的风险等级，因地制宜地制定风险应对策略，为农业防灾减灾提供理论支持和政策建议。

Abstract:

In order to improve the level of scientific response to flood disasters in rural areas and reduce agricultural losses, a risk assessment model for agricultural flood disasters is developed to have a good command of the source of flood disaster risk in the selected area and the sensitivity analysis of each index is carried out to grasp the influence degree of the index on risk assessment, then the risk response strategy is effectively developed. In the context of the meteorological, geographical and social economic data of Weifang in 2018 years, the risk assessment index system of agricultural flood disaster was established, the entropy weight method was used to determine the weight of each index, and WGA operator was used to analyze the sensitivity of the index, and Weifang risk assessment value was obtained through this operator, then Weifang agricultural flood disaster risk grade map was drawn with GIS. On this basis, risk prevention measures were formulated. The results were obtained in this paper are as follows. (1) The sensitivity of indexes of the terrain elevation difference and river network density was the highest, followed by the maximum daily precipitation, and the sensitivity of indexes of rainstorm frequency, that of precipitation in flood season, average local agricultural GDP and health institutions was low. (2) In Weifang, the risk of disaster-causing factors decreased gradually from west to east. The most sensitive areas of disaster-prone environment were the mountainous areas in the west and south of Weifang, with large undulation of terrain and numerous rivers, which could easily cause flood disasters. The hazard degree of disaster bearing body in Weifang city was gradually decreasing from northwest to southeast. The area with weak disaster prevention and mitigation capacity was located in the middle of Weifang city. (3) The overall trend of comprehensive risk in Weifang gradually decreased from the southwest to northeast. (4) For the regions with high frequency and intensity of rainstorm, it was necessary to improve the timeliness and accuracy of meteorological early warning, and appropriately adjust the sowing time of crops, and for the disaster sensitive environment areas, to build water conservancy projects, forestry development. As for the vulnerable areas of agriculture, we should pay attention to the cultivation of water logging-resistant crops to strengthen the self-help of agriculture industry. And to enhance disaster prevention capacity, we should implement corresponding insurance agreements, popularize relevant disaster prevention and mitigation knowledge, so as to reduce the losses brought by floods to agriculture. Through the agricultural flood disaster risk assessment model, we can investigate the risk level of each area in Weifang city, formulate risk response strategies according to local conditions, and provide theoretical support and policy suggestions for agricultural disaster prevention and mitigation.