Risk Assessment Of Rice Chilling Injury In Heilongjiang Province

Heilongjiang Province is an important rice production region and commodity rice production base,its bumper or poor harvest in rice will have an immediate impact in food security and social stabilization in our country.The geographic latitude of Heilongjiang Province is high,which easily leads to chilling injury of crop.Under the influence of global warming in recent years,thermal resource in Heilongjiang Province is greater,but fluctuation and instability of annual temperature is continuously increasing as well,chilling injury is still the major disaster which impacts local rice production.In this paper we study on rice in Heilongjiang Province.The day by day meteorological data,rice growth data,planting area and production data of 56 sites in Heilongjiang Province from 1980 to 2011 are employed as the basic data.We analyze rice damages and chilling climate in Heilongjiang Province by using IDW Interpolation of Geostatistical Wizard method in ArcGIS,linear moving average method,probability statistics,etc.And based on the theory of natural disaster risk analysis,we evaluate the rice chilling injury in Heilongjiang Province by setting up the risk assessment model including four factors,the hazard,vulnerability,exposure,and emergency response and recovery of hazard-affected body and also do spatial analysis and mapping by leveraging ArcGIS(10.2)software platform.The main conclusions of this article are as followed:(1)The analysis of rice damage risk in Heilongjiang Province indicates that slight crop fa ilure has the maximum probability of the occurrence among different degrees of reduction yea rs.The probability of the occurrence of crop failure in the corresponding degree decreases wit h increasing yield reduction rate.The probability of slight crop failure in the central and south of Heilongjiang Province is greater than north area,while the probability of severe crop failur e is less than north area.The distribution of average yield reduction rate in Heilongjiang Provi nce is in an irregular shape of latitudinal zonation,average yield reduction rate increases from south to north,the high value of this rate concentrates nearby Heihe City in northwest.The di stribution of variable coefficient of yield reduction rate in Heilongjiang Province is significant different from the average yield reduction rate.The difference between average yield reducti on rate and the variable coefficient indicates that the higher latitude region of Heilongjiang Pr ovince are generally to be stable with high yield reduction rate,while in south of Heilongjiang Province,the average yield reduction risk in calendar years is low,however,the fluctuation o f inter-annual production is great,grain production is not stable.(2)It analyzes the spatial distribution of the reason why chilling injury of rice in Heilongj iang Province divides into delayed-type and sterile-type chilling injury.General delayed-type chilling injury mainly distributes in north and southeast of Heilongjiang Province and severe delayed-type chilling injury mainly distributes in northwest of Heilongjiang Province;Sterile-type chilling injury has little impact in booting stage and mainly occurs at heading to followin g stage.(3)To obtain integrated risk index of chilling injury in Heilongjiang Province by examining the reasonability of the four indexes in modelling risk assessment.The result indicates that:risk of chilling injury is between 0.14 and 0.68,and increases from south to north.Dividing Heilongjiang Province into four chilling injury risk areas,5 regions are with low value of risk,such as Mudanjiang city,Shuangcheng city,Suihua city,Wuchang city and Zhaodong city.19 regions are with medium-low value of risk,which are located in the central,southeast and southwest of Heilongjiang Province.26 regions are with medium-high value of risk,which are distributed contiguously in north of Heilongjiang Province.And 6 regions are with high value of risk,such as Beian city,Fuyuan city,Hegang city,Heihe city,Gannan county and Qitaihe city.