The Spatial And Temporal Distribution Of Rice Heat Injury In Hubei Province

The spatial and temporal distribution of rice heat injury of present and future in Hubei province were studied by analyzing the climatic data of 70 weather stations in recent 34 years. Heat injury is one of the main weather disasters for rice crop in Hubei Province, a main rice planted area in Central China. A mathematical model is used to simulate time series of the probability of occurrence of rice heat injury for every day in rice plant season. Based on the model, the spatial and temporal distribution characteristics were expressed and Hubei was divided into six regions with different risk level for heat injury. And some suggestions were proposed for preventing or decreasing damage of the disaster. For evaluating the evolution of the risk for rice heat injury in the global warming future, 1℃ of temperature rising was assumed and the mathematical model was also used to described the possible change of occurrence probability for the hot weather damage. The main results could be summarized as follows.1. The agrometeorological quantitative threshold was proposed as maximum temperature higher than 35℃ in 3 days or longer. Based on the threshold, the probability of the daily durative high-temperature events from May to September was analyzed. To simulate the daily durative high-temperature events, the simulation model was used with three parameters d out by the least squares and non-line programming. By fitting test, it proved that the model was fit to most of weather station very well.2. The maximum probability and its occurrence date counted by the simulation model showed that the date with the maximum probability occurred during the last ten days in July in most of weather stations in Hubei. Moreover, the maximum probability was very different in different areas. It was higher in southeast and northwest (Badong, Xingshan and Zigui) than others in Hubei. The lowest value of the maximum probability appeared in Laifeng and Jianshi of southwest in Hubei.3. According to the probability of the durative high-temperature events, four different heat-injury grades were proposed. Although different areas had different duration and occurrence date, the spatial and temporal distribution follows a regularity approximately: the maximum probability of the durative high-temperature events appeared very earlier in southeast and northwest of Hubei , last longer and terminated later. On the contrary, it appeared later, last shorter and terminated earlier in southwest and Jianghan Plain.4. In order to evaluate the risk level of heat-injury for different regions, duration of...