江西省南昌县血吸虫感染率时空格局演化研究

Evolution of spatial-temporal pattern of schistosome infection rates in Nanchang County,Jiangxi Province

目的探索江西省南昌县血吸虫感染率时空格局演化规律。方法基于2006-2009年南昌县以行政村为单位的血吸虫感染率数据,利用全局Moran s I、全局Getis OrdG、局域Getis OrdGi*指标和变异函数分析南昌县鄱阳湖沿岸104个行政村血吸虫感染率的空间格局演化。结果自2006年以来,血吸虫感染率全局Moran s I指数不断增大,Getis OrdGeneralG统计指标G(d)值均为0.02,Z(d)值检验均有统计学意义(P均<0.01);热点区域主要分布在东北部与东南部,冷点、次冷点区域主要分布在西南部;3年的最优空间变异拟合函数均为Gaussian模型,块金系数从0.026降到0.006;血吸虫感染率的空间自相关越来越强,变程缩小9.04%。结论南昌县血吸虫病疫情逐渐向沿湖地区集聚,结构性因子的影响逐步上升,但空间关联效应的作用范围逐渐减小。

Objective To explore the evolution of spatial-temporal pattern of schistosome infection rates in Nanchang Coun- ty, Jiangxi Province. Methods Based on the data of schistosome infection rates at unit of administrative villages during 2006 to 2009, the evolution of spatial-temporal pattern of schistosome infection rates was analyzed by means of global Moran＇s I, Getis- Ord General G, local Getis-Ord G＊ and variogram. Results Since 2006, the global Moran＇s I index increased, and all the Getis- Ord General G index G （d） values were 0.02, all the Z（d） values were of statistic significance （all P values were 〈0.01 ）. The hot- spots mainly distributed in the northeast and southeast of the county, while the cold spots and secondary cold spots mainly distrib- uted in the southwest. The optimal fitted variograms of the 3 years were all Gaussian model, the Nugget coefficient decreased from 0.026 to 0.006. The spatial autocorrelation of schistosome infection rates got stronger, the ranges shrank by 9.04%. Conclusion The schistosome infection rates in Nanchang County have a tendency of clustering towards the areas along the lake, and the impact of the structural factors is increasing, but the effect range of spatial correlation is decreasing.