Temporal And Spatial Distribution Of Cold Damage And Freezing Injure In The Context Of Climate Change In Guangxi

Cold and freezing injury is one of the main meteorological disasters in Guangxi. In order to provide scientific advice for wintertime agricultural production and establish suitable disaster prevention and reduction policies and measures in Guangxi, in this paper, we analyzed spatio-temporal variability of winter temperature and precipitation in Guangxi by using winter mean daily temperature、daily minimum temperature and daily precipitation of88meteorological stations in Guangxi from December,1961to February,2010. Based on the study of predecessors, select13new disaster-inducing factors of cold damage and freezing injure. According to the analytic method to the principal component, build the wintertime integrative chilling damage index of Guangxi and the comprehensive index of January freezing injury in some stations of Guangxi. Calculate the cold damage integrated index HI and freezing injury integrated index DI, according to the value of HI and DI, divide the cold and freezing injury into different levels, analysis them inter-annual variations and spatial distribution of the first and second eigenvector of them combining with GIS and some interpolation methods. The main results are as follows:1、The result showed that the trends of winter mean temperature and the average temperature of January and February and the annual minimum temperature are increasing in the recent50years, In spatial distribution, the high tendencies mainly distribute in the northeast and northwest and southeast of Guangxi.2、Winter precipitation, January precipitation, February precipitation change are increasing. Winter precipitation days with above5mm decline.Winter precipitation and the winter rainfall days does not change the number of synchronization, but in the period of large fluctuation of temperature, precipitation is corresponding. Regional precipitation in the northeast trends to the most obviously and in west areas trends to increase higher and in the southeast the trend is weaker.3、Selected13new disaster-inducing factors of cold damage and freezing injure. The result showed that cold damage and freezing injure happen every year in Guangxi, just on different range. The spatial distribution of harmful accumulated chilling descend from north to south, alpine region more than river valley, and plains with the same latitude.4、Build the wintertime integrative chilling damage index of Guangxi(HI), the trend of HI declines, the values of spatial-coefficients of the first feature vector field of HI are positive, in the spatial distribution perform consistently, values in the northeast are high, in which chilling damage is serious,; spatial-coefficients of the second feature vector field present the east-west distribution pattern, the values in the east areas most are negative and in the western basically are positive, where chilling damage maybe become more serious in the future, so we should enhance protection consciousness.5、Build the comprehensive index of January freezing injury in some stations of Guangxi(DI), inter-annual variability tendency of DI is decreasing, the values of spatial-coefficients of the first feature vector field of DI are positive. The first feature vector field changes the same trend and the largest vecor-valued concentrate in the northeast where freezing injure is the most serious; The spatial distribution of the second feature vector field is that positive and negative values distinguish piece of concentration, the values in the northeast are positive and largest, so in the future freezing injure in this area will become more serious.