Research Of Climatic Production Potential Of Cotton In China Based On The AEZ Model

This paper is based on the weather site by the National 614 1974-2003 30-year meteorological data base, the Chinese DEM data, using Excel, Access database software and ArcGIS 9.3 software calculation, order of meteorological data. It obtains the data by calculating the meteorological stations in solar radiation, in photosynthetic active radiation, sunshine hours, sunshine percentage, average temperature, accumulated temperature and other climatic factors; using the moving average method used on the 5th (one of the methods commonly used in China)it calculates the temperature stability of the temperature through a boundary all day long , combines with the completion of different growth stages of cotton accumulated temperature, and with the design process using Visual Basic 6.0 calculates the growth stage of cotton each day corresponding to the beginning, by the day and all day from the beginning of agro-ecological regions calculated model(ie AEZ : Agro-ecological Zone model) one of the important parameters-growth period, and then chooses the other model parameters of cotton based on relevant information and documentation, using the international AEZ model widely used in all meteorological stations in the various it estimates cotton growth stage photosynthetic production potential, then by using the temperature and effective coefficient of water it revises and gets the sequential light moderate rain production potential.The calculated production potential of climate factors and climate data is expressed with the ArcGIS 9.3 analysis and visualization software . First, it applies the spatial statistics, spatial autocorrelation and semi-variogram and other methods to climate factors (including the three climatic factor conditions suited to China cotton growth) data for spatial autocorrelation analysis, the data distribution characteristics and trend surface, in which if it is necessary to change variable quantity, it can eliminate trend surface. For the conditions of the interpolation of data it tries to use a variety of spatial interpolation methods (such as inverse distance weighted interpolation, polynomial interpolation, spline interpolation, kriging interpolation ,etc.) to select the interpolation parameters of spatial interpolation, error analysis and interpolation accuracy of this model, the appropriate interpolation methods and parameters of interpolation generates grid maps. Through calculator and grid computing, editing, processing it generates surface boundary layer of cotton planting; it exports the vector layers from the data of interpolation results at all levels, and does overlay analysis to take the intersection with the income limits of surface layers of cotton cultivation .Lastly ,it gets planting area of cotton production potential at all levels of weather maps.The results show that the agro-ecological zones of China cotton production potential at all levels, there are significant differences in photosynthetic potential of the national average lint 62289.01 kg/hm2, high values found in Shandong, Yunnan and Xinjiang, the low area located in Jilin, Hunan and Guizhou, the country the potential of light and temperature average lint 4207.541 kg/hm2, high values found in Sichuan, Henan and Xinjiang, the low area located in Jilin, Liaoning and Tianjin, the national cotton production potential of precipitation an average of 3232.795 kg/hm2, high values found in Guizhou, Zhejiang and Fujian, and other low areas located in Xinjiang, the Xinjiang and Guizhou.The reason leading to disparity of precipitation and the production potential of light and temperature ,on one hand,is mainly due to rainfall caused by regional differences, on the other hand because of irrigation making up for the lack of precipitation, the actual lint Xinjiang, but a higher yield; at different growth stages of cotton flowering and boll production potential of the light and temperature accountes for the largest share of production potential in the same period of photosynthetic, up to about 7.35%, the smallest proportion of seedlings. In addition, the potential photosynthetic production is during the cotton flowering and boll formation period and mainly in the boll opening stage, which accountes for 31.49% and 28.52%; the production potential of light and temperature are mainly in the flowering and boll formation period and boll opening period, accounting for 34.84% and 27.62%; seen from the districts of the actual average yield to lint, high values is found in Inner Mongolia, Gansu ,Jilin , Liaoning and Xinjiang, the most up to about 83.35% of the production potential of light and temperature, the low area is located in Sichuan, Yunnan and Guizhou , the list to about 83.35% of it. On this basis, combined with the actual calculation of cotton potential of China's cotton yield, In the rain clouds and more difficult to achieve the potential of regional output, while little precipitation, but can yield potential of irrigated areas easier to achieve, from a national perspective, the average yield great opposite potential(69.44%). It provides for Chinese agricultural production and the development of strategic of cotton with basic information.