Temporal And Spatial Variation Characteristics Of Oncomelania And Schistosomiasis And Its Relationship With Environmental Factors In Dongting Lake

Schistosomiasis is a kind of infectious or parasitic disease which seriously harms tohuman health and restricts social economic development. China is one of the countries mostaffected by schistosomiasis. Currently, the researches on schistosomiasis are focused on theprevention and control of schistosomiasis. Meanwhile, domestic and foreign scholars havedone a lot of related researches about the relationship between schistosomiasis andenvironment factors (Hydrological characteristics, temperature, vegetation, et al). Studieshave shown that environmental conditions are decisive factors affecting survival ofoncomelania and schistosomiasis transmission. With the operation of Three Gorges Dam,climatic variation, the implementation of return land to lake policy, et al, the influence of thechange of the water and ecological environment of Dongting Lake on the survival of snail andthe spread of schistosomiasis research remains to be further developed.The study, proposed Dongting Lake area as the research object, has studied on thetemporal and spatial variation characteristics of oncomelania and schistosomiasis and itsrelationship with environmental factors. It mainly based on the datas of schistosomiasis,MODIS and water level of this region and with the help of ENVI, GIS and other statisticalmethods. The results are as follows.（1）The research results of spatial and temporal variations of schistosomiasis epidemicin Dongting Lake showed that: the acute schistosomiasis of Dongting Lake region wasdeclined significantly. In recent years it has been controlled within20cases, and juvenilecases had greatly reduced; overall the human schistosomiasis was presented an upward trend,it increased gradually from2001to2003and rose considerably from2003to2006, followedby an obvious decrease in2007, it was continued to increase after2007, and the higherschistosomiasis regions showed an outward expansion trend; the bovine schistosomiasis roseslightly from1996to2003, while it continues to decrease after2003, in2010, it was declined62.76%than2003. More serious area of human and bovine schistosomiasis was near the lake.（2）The research results of the probe of oncomelania suspicious breeding ground basedon MODIS data in Dongting Lake and its spatial and temporal variation characteristicsshowed that: the multi-source information water extraction method which based on MODISRemote Sensing used in the probe of oncomelania suspicious breeding ground had goodapplication effects; the oncomelania suspicious breeding ground had an obvious decrease, thevalue in2007was just39.40%of that in2003, in2008it was just40.01%of that in2003;and it had a significant reduction in East and South Dongting Lake region after2003, WestDongting Lake region just had spare areas suitable for snail breeding after2004. （3）The research of the relationship between schistosomisis and environment factorsshowed that: some changes have occurred in surface area, water level, bottomland floodingtime and other environmental factors of Dongting Lake area in recent years; and there aredifferent degrees of correlation between environmental factors and schistosomiasis. The waterlevel and the bottomland flooding time in October had significant negative correlation withhuman scistosomiasis. The square of the correlation coefficient was reached-0.800and-0.773,respectively. And there was good regression model fitting effects between the water level andthe bottomland flooding time of October and human schistosomiasis. Future development ofhuman schistosomiasis can be preliminary forecast based on the water level and thebottomland flooding time of October.