基于GIS的大连冰雹分布与地形因子的相关分析

利用1971-2010年大连地区64个乡镇的冰雹观测资料和1:50 000数字高程模型，选择和设计对冰雹空间分布可能有影响的地形因子，如海拔高度、坡度、坡向、地形起伏度、地形切割深度等，采用数字地形分析、不规则窗口统计等方法研究冰雹分布与地形因子间的相关关系。结果表明：地形高程、西北偏西坡向和地形切割深度是影响大连地区冰雹分布的最主要地形因子。地形高程抬升下的强对流天气系统有利于降雹；西北偏西坡向有利于冰雹的形成；地形起伏显著的区域更有利于冰雹的形成和降落。建立了冰雹与地形因子间的回归方程，模拟了大连地区的冰雹空间分布，结果显示大连地区冰雹最严重区域位于瓦房店和普兰店北部地区，沿海及南部地区较少。

Distribution of hail and its correlation to topographical factors based on GIS in Dalian

Based on the observational hail data from 64 weather stations from 1971 to 2010 and 1：50 000 digital elevation model （DEM） in Dalian,the topographical factors such as elevation,slope,aspect,relief amplitude and terrain incision depth which can be extracted from digital elevation model were selected as potential affecting factors,and the relationships between topographical factors and hail were analyzed using methods of a digital terrain analysis and an irregular zonal statistics and so on.The results indicate that mean elevation,west-northwest aspect and terrain incision depth are the major factors affecting the distribution of hail.With the increase of elevation,the occurrence probability of hail increases.The west-northwest aspect and complex topography are favorable to the formarion of hail,especially for the latter.Finally,a regression equation is established to simulate the relationship between the hail and topographical factors,and the distribution map of hails is simulated.It shows that the serious hail disaster occurs in the northern Wafangdian and Pulandian,while it is seldom in the coastal and southern regions.