Application of GIS to optimum distribution of Longan planting in Guangxi Zhuang Autonomous Region

There are favorable climatic conditions for Logan planting in Guangxi Zhuang Autonornous Region, but it does not acquire the ideal economic benefit because of irrational variety structure and regional distribution. The intention of this paper is to study how to optimize the regional distribution and variety structure of Longan planting in Guangxi Region. Based on the biological characteristics of Longan and the corelation analysis between Longan yield and climatic factors, it was selected that the limiting climatic factors of longan growth and the key climatic factors that affect its yield, then the climatic zoning indices of Longan growth were ascertained. Using the climatic data of the 89 weather stations in Guangxi and the data of landform on the scale of 1∶250000, the spatial analytical model of zoning indices was built. The zoning indices include the following geographic parameters: longitude, latitude, elevation, slope, etc. On the GIS platform, the zoning indices were calculated according to the grids of 1 km×1 km, and the differences were reckoned by the spatial interpolation method with anti-distance weight. Thereafter, the results of calculation and differences were added, it realized the revision of zoning indices to the data of small grid and made the result more accurate. Supported by the GIS technique, the zoning for Longan planting region was done. Guangxi was divided into the optimum, fit, sub-fit and unfit climatic regions according to climatic adaptability of Longan, and small grid zoning map for special topics was drawn. On the basis of above, the optimum variety distribution of Longan planting in Guangxi was studied, and the rational planting regions for the varieties of early, middle and late mature Longan were divided, and the analysis, evaluation and related planting suggestions for every region were made. The results of this study provide the scientific basis for optimizing the distribution of Longan planting in Guangxi Region.