ANALYSIS OF ONCOMELANIA HUPENSIS′S DISTRIBUTION CHARACTERISTICS IN JIANGHAN PLAIN BASED ON GIS SPATIAL AUTOCORRELATION

Schistosomiasis,aparasitic disease in tropical and subtropical areas,has serious threats to human health.Hubei Province is a serious infected area.A large number of schistosomiasis patients distribute in Jianghan plain in this province.According to annual schistosomiasis statistics,the number of schistosomiasis patients in Jianghan plain made up approximately 90 percent of the population of schistosomiasis patients in Hubei Province.So,the difficulty of controlling Oncomelania hupensis in Jianghan plain is both general and representative in our country.In recent years,the achievements of schistosomiasis control work are remarkable in Hubei Province,but outbreaks still occur.Some efforts have to be made to achieve the goal of interrupting schistosomiasis transmission.Oncomelania hupensis serves as the only intermediate hosts,whose distribution is strongly associated with the transmission of schistosomiasis.So,accurate understanding of the spatial and temporal distribution characteristics of Oncomelania hupensis and discovering environment factors that affect the temporal and spatial distribution characteristics of Oncomelania hupensis from the results is advantageous to the prevention and control of Oncomelania hupensis diffusion,which can provide spatial analysis and supported decision for department of schistosomiasis control quickly.In this paper,we applied ArcGIS to establish the Oncomelania hupensis′s distribution database based on Oncomelania hupensis′s area distribution data in Jianghan plain for five years from 1990to 2009.The global autocorrelation analysis,cluster and outlier analysis and hot spot analysis are applied to present the spatial-temporal distribution characteristics of Oncomelania hupensis in 1990,1995,2000,2005and 2009.The results of global autocorrelation analysis with time series data based on GIS indicate that the distribution areas of Oncomelania hupensis are highly clustered from 1990to 2009.The cluster and outlier analysis showed that different villages present the distributional patterns of Oncomelania hupensis as follows.The high values are clustering(HH),the high value is mainly surrounded by low value(HL)and the low value is mainly surrounded by the high value(LH),and the number of villages with HH type is large.The distribution of Oncomelania hupensis in other administrative villages without statistical significance is randomly distributed.And the spatial positions of different distribution patterns are displayed obviously."Positive hot points"areas of high distribution rate are identified in this area.The distribution of Oncomelania hupensis is larger in adjacent area between Xiantao and Honghu for five years.Besides,the results of spatial autocorrelation analysis show that there are some time-varying regulations about distribution characteristics of Oncomelania hupensis from 1990to2009.It′s much cluster before 2000.The distribution patterns and hotspot area of Oncomelania hupensis in 1990is different from other four years.But it′s similar in 1995and 2000,2005and 2009respectively.Thus,1990,2000and 2009is the important timing notes.The results of the research are of great theoretical and practical significance for controlling the diffusion Oncomelania hupensis and reducing the spread of schistosomiasis.