Risk Evaluation And Regionalization Of Heat Injury For Single Rice In Middle And Lower Yangtze River

Rice has been very important in agricultural production, and rice has been very sensitive to high injury, in addition, the situation of heat injury will became more serious with the global warming. So the risk evaluation of heat injury for Single Rice will have important realistic meanings, and provide scientific evidence for rice cultivation management and damage prevention and mitigation in future agricultural production.Meteorological data, crop data for single rice, soil physical data from Harmonized World Soil Database (HWSD) in the middle and lower Yangtze River were considered in this study. Based on the level index of heat injury for single rice during flowering period, the frequency of the damage with different intensities of each station and each year was counted up, the horizontal distribution of heat injury was analyzed by ArcGIS, and the periodic trend was analyzed by wavelet method. The two weather-programs were setted, which were with and without heat injury during flowering period, and the damage rate of heat injury was extracted by ORYZA2000 model, the risk degree was calculated by the model of damage risk evaluation, and then the risk regionalization of heat injury were achieved by ArcGIS. The main results show as ofllowing:(1)The spatial-temporal feature of heat injury frequency for single rice. The heat injury frequency in inland area was higher than that in coastal area, the heat injury prone areas:the midwest and and eastern of Hubei, the midwest and north-central of Hunan and the midwest of Anhui. The distribution area of heat injury frequency were:slight>moderate>severe.The ages of total, slight, moderate, severe heat injury with high frequencies were 60s,00s,60s and 60s respectively, the ages of with largest increases were 90s、90s、00s and 60s respectively.28a was the first major period, heat injury frequency had an altering process from much to little to much with the period, and will decrease after 2013.(2)The statistics of heat injury for rice during different development stages or length of time, had impacts on the research results of its occurrence rule.The flowering stage of single rice between 1961-2013 with each station was defined by this article, the regions where heat injury has happened most frequently were the northwest, southwest, midwest and eastern of Hubei respectively.(3)The areas of high heat injury damage rate for single rice:The south of Suqian, the south of Huaian in Jiangsu province, the junction of Shaoxing, Jinhua and Taizhou in Zhejiang province, the southwest of Hangzhou, the northwest of Quzhou, Huangshan in Anhui province, the south of Huaihua in Hunan province. The trend of high damage rate region along with five decades:the central of Jiangsu�'the north-central of Hunan�'the north-central and southwest of Hunan�'the central of Zhejiang,the north-central of Hubei�'the central of Zhejiang�'the southeast of Anhui. The fluctuation of damage rate had been weakened since the nineties,and the value had a slight decline.(4)The areas of high risk of heat injury for single rice were the northwest of Lu’an, the junction of Lu’an and Anqing in Anhui province, the west of Xiaogan, Xiantao, the east and south-central of Jingmen, the northwest of Xianning in Hubei province, the junction of Changde, Yiyang and Yueyang in Hunan province.