A Refined Spatial Division of Freezing Injury to Litchi Base on Digital Elevation Model:A Case from Zhangzhou
The spatial models about winter extreme low temperature and 4 levels'(-2 Td≤0℃,-3 Td≤-2℃,-4 Td≤-3℃,Td -4℃) cold damage model were built,by using stepwise regression analysis and GIS technology,then the planting areas of Litchi in Zhangzhou were divided according to the grading index.The result showed that:1) the planting areas of Litchi in Zhangzhou were divided into slight freezing injury areas,mild freezing injury areas,moderate freezing injury areas,and severe freezing injury areas.Slight and mild freezing injury areas are consistent to real planting areas of Litchi;2) slight and mild freezing injury areas are located in the southeast and northwest of Zhangzhou with low mountain and hills,moderate and severe freezing injury areas are located in the west parts with higher mountains.