Study On Risk Assessment And Zoning Of High Temperature Hazard For Late Rice In Zhejiang Province Based On IDM And FIS

In the context of global climate change,high temperature events occur frequently,and agricultural is one of the industries most sensitive to climate change.In recent years,many scholars around the world have taken the impact of climate change on society as the main research content,trying to find the key elements to solve these problems.China is both a big rice producer and a rice consumer.Therefore,studying the impact of climate change on rice in China is getting more and more attention from scholars.Many scholars have studied the relationship between rice and high temperature in Zhejiang Province,but these studies have focused on the correlation between rice yield and high temperature lasting days,and the research results of rice high temperature risk assessment and zoning are relatively rare.It is of great theoretical and practical significance to study the distribution and zoning of high temperature risk for rice in Zhejiang Province.It can not only provide a scientific basis for the government and farmers to make rice production planning decisions,but also has a certain guiding role in the prevention and control of high temperature heat damage in rice.The main work of this paper is as follows:(1)Determining the hazard factor and constructing the vulnerability curve.Based on the 1994-2016 daily meteorological data of Zhejiang Province and the yield data of late rice in different regions,the paper uses Matlab software to call the regress function to determine the meteorological factors and hazard factor affecting the yield of late rice in Zhejiang Province,and the functional relationship between the intensity of the hazard factor and the loss of late rice is constructed,that is,the vulnerability curve.(2)The information diffusion model and spatial interpolation model were used to evaluate the risk of high temperature hazard loss in late rice in Zhejiang Province.On the basis of determining the hazard factor,the annual disaster intensity index values of 19 meteorological stations in Zhejiang Province from 1994 to 2016 were calculated,and the information diffusion model was used to obtain the hazard intensity index values with different return periods.And based on this,the distribution of the hazard intensity index is obtained by using two interpolation models,Anusplin and Cokriging.According to the hazard risk assessment model,the results of high temperature risk assessment of late rice in Zhejiang Province were obtained.(3)High temperature risk zoning of late rice is conducted based on fuzzy inference system model.Based on the selection of high temperature risk zoning evaluation indicators for late rice in Zhejiang Province,the fuzzy inference system model is used to obtain the comprehensive value of high temperature hazard risk level of various administrative units in Zhejiang Province.On this basis,the risk zoning of high temperature hazard in late rice is carried out.The conclusions of the paper are as follows:(1)Among the many factors affecting the yield of late rice in Zhejiang Province,the daily maximum temperature value and days above 35°C are the main meteorological factors for the decrease of late rice yield in Zhejiang Province.With the increase of the level of recurrence,the intensity of the hazard increases.At the same return period,the high value centers of the hazard intensity index are located in Lishui and Yunhe,and there is a tendency that spread from the areas to the surrounding areas.On the whole,the value of the disaster intensity in the central part of Zhejiang Province is generally higher than that of its surrounding areas.(2)Under the same recurrence of hazard intensity,the risk of high temperature hazard loss in late rice in Zhejiang Province is diminished by the spread of Lishui and Yunhe as high values centres.Under the different return periods,the risk distribution trend of high temperature hazard loss of the late rice in study area is about the same,with Yunhe and Lishui as the centers of high risk areas,showing a trend of weakening to the surrounding areas.The difference is that as the recurrence level increases,the risk of late rice loss increases gradually.Under the disaster intensity of once in 100 years,the risk of late rice loss in the whole study area is higher,but the southeast coastal areas and parts of Zhoushan still have low risk of loss.(3)Through the fuzzy inference system to calculate the comprehensive risk level,it can be seen that the value of high temperature hazard risk rating in Zhejiang is between 0.172 and 0.793,the risk level of Zhoushan City is the smallest,and the value of risk of Longyou County is the largest.The lower risk areas are mainly located in Taizhou City,Jiaxing City and Wenzhou City.The intensity and frequency of high temperature in these regions are lower,so the comprehensive risk level is lower.The high risk areas are mainly located in the central cities of Zhejiang Province.Because the intensity and frequency of high temperature in these cities are higher,and the planting area of late rice is more,and the corresponding loss of yield of late rice caused by high temperature will also increase.At the same time,the economic level of these areas is lower than that of Hangzhou and coastal areas such as Ningbo City.Therefore,the ability to resist hazard in these areas is weaker than the areas with better economic development,so the risk zoning level is higher.In summary,the evaluation indicators should be selected from multiple angles,multiple directions,and multiple levels,so as to conduct risk zoning comprehensively and objectively.