松树萎蔫病发生中心化趋势和扩散模式研究

The Central Tendency of Pine Wilt Disease and Its Range Dispersion Mode

基于GIS挖掘松树萎蔫病发病林型几何质心,利用空间计量统计的方法探求松树萎蔫病扩散的模式。结果显示:滁州地区松树萎蔫病的发生呈现随机分布的态势,空间均值模型和加权标准化距模型的计算发现松树萎蔫病发生的空间特征向量-空间均值点位与首次江苏省松树萎蔫病发病区域的江浦区有较近的空间距离关联,空间均值出现在全椒县东北方位、滁州县东南方位和江苏南京市江浦区西侧方位的区域,加权的标准化距(STD)为58.133km,理论上推断以该均值点为中心,发散范围可以达到周边以58.133km为半径的区域。根据加权标准化离均差椭球参数(SDE)模型拟合得出松树萎蔫病发病点理论扩散趋向为西北-东南方向与正北左倾为62.373的角度,理论扩散的范围为长轴46.75km、短轴20.34km的椭形区域。

Employing GIS technique to mine centroid of forestry stands, associated with spatial statistic to analysis the point range pattern of Pine Wilt Disease （PWD）. Through the visualization of the mapped centroid PWD occurrence distribution, showed that PWD status in Chuzhou and Maanshan region loomed to be a sporadic random range. Further insights were derived that weighted spatial mean of the centroid point of PWD were detected locating in the country closely neighboring to the Jiangfu county, where national first case of PWD were diagnosed and confirmed. Weighted Standard Distance （STD） were derived to be 58. 133 km, which indicted that PWD could be theoretically dispersed within a radius of 58. 133 km. The parameters of the weighted standard deviational ellipses （SDE） were derived that the angle of the deviation along the north were calculated to be 62. 3730, revealing that the direction of northwest-southeast could be the PWD main dispersion tendency. The deviation along minor axis and major axis were calculated correspondingly to be 46. 75 km and 20. 34 km, showing that ellipses region characterized above parameters could be ranged by PWD potential dispersion.