The Analysis And Research On The Snail Information Based On Spatial Data Mining And GIS Technology

The distribution of snail has a direct impact on the distribution of schistosomiasis.Effective controlling of snails is the most effective controlling and prevention of schistosomiasis disease.But the distribution of snail and its environment are closely related to natural factors,and it has a certain spatial characteristics,so researching on the environmental factors of the snail of distribution and spatial characteristics is greatly significant.Spatial data mining is a study branch that is formed with the combination of geographic information systems,remote sensing image processing,global positioning systems, pattern recognition,visualization and other related areas of research,it also is named as spatial data mining and knowledge discovery(referred to as SDMKD),it is a technology of founding knowledge from the spatial database,specifically extracted from that the users are interested in spatial patterns and characteristics,spatial and non spatial data in general and some other relations hidden in the database features of the universal data from the spatial database.GIS is the product of the combination of computer technology,database technology,image graphics technology,it is a management and research on spatial data technology system.So the combination of GIS and Spatial Data Mining Technology will provide a new instrument to study the snail distribution and the relationship among the environmental factors.This article has two main features.One of them is that the layers of distribution of snail information is the grid map in this article,that is,the layers are displayed in various snail designated area(box),and the box is colored in different colors according to the number of snails to show the status of their distribution.As the grid showing the distribution of snail can identify specific geo-spatial location on the snails maps,it is also named as data-driven approach(instead of model-driven approach) and it is to be a more accurate location of physical space on the distribution of the snails and spatial characteristics of the situation.The second feature is that it is the first time to analyse the snail information of the Changsha segment of Xiangjiang river with the data-driven and spatial analysis methods.In this study,with the snail distribution information of the survey in islands of Changsha segment of Xiangjiang River from 2005 to 2008, firstly,the article deals with the data and gets the 1:10000 topographic maps of the elements of digital maps,uses the technology of RS for remote sensing image processing and gets the distribution map of vegetation type,the distribution map of soil moisture and the map of normalized difference vegetation index.And then,it completes the operation of geographic registration and overlay on these layers which comprise of the map of topographic factor,the map of snail information and the map of vegetation types with the support of GIS technology. Finally,based on the above layers,this article makes more comprehensive analysis on the environmental conditions of snail's habitat with making the use of spatial analysis and statistical method and GIS technology.It finds that the types of vegetation are mainly weed, reed and sedge on the islands of Changsha segment of Xiangjiang River where there are snails.Most(80%) of snails are living in the place where the normalized difference vegetation index is between 0.100 and 0.382 and soil moisture is between 0.102 and 0.389529,90%of the distance of between net grids where there are snails and the water layer is between 20 and 90 meters,the changes of the water level have a great impact on the distribution of snails,the linear regression model y=24.924 +0.091 x(F=0.017＜0.05) shows that there is a positive relation between the distribution of snail and the water level.During these years,from 2005 to 2008 year,65 percent of the amount of the snails and alive snails decreased significantly.