江汉平原土地利用对钉螺分布的影响研究

IMPACT OF LAND USE ON ONCOMELANIAS DISTRIBUTION IN JIANGHAN PLAIN

分析了江汉平原2009年易于钉螺孳生的3种土地利用类型(滩地、河渠和水田)比例与钉螺密度的关系。首先,在ERDAS9.2和ENVI4.7软件中对江汉平原2009年的Landsat5TM遥感影像进行了预处理。在已有的多期土地利用数据的基础上,借助eCognition软件利用向量相似度指标来提取土地利用变化区域,结合目视解译经验并运用遥感指标通过建立规则集对变化区域进行分类,将变化区域的分类结果更新2000年数据,得到了该区域2009年的土地利用数据。接下来,整理了江汉平原2009年螺情资料并计算出村级钉螺平均密度,绘制了2009年钉螺分布图。将绘制的钉螺分布图与土地利用分类图叠置分析,并结合收集的螺情数据确定了钉螺易于孳生的3种土地利用类型,分别为滩地、河渠和水田。最后,将钉螺密度与这3种土地利用比例进行线性回归分析。研究结果表明,钉螺密度与这三种土地利用类型比例存在线性回归关系,模型精度为R2=0.857。该结论对通过遥感影像来估算钉螺密度具有指导意义,另外也可以为湖北省提出合理用地和灭螺并重的土地利用模式提供一定的科学参考。

Schistosomiasis,a parasitic disease in tropical and subtropical areas, has serious threats to human health. Hubei Province is a serious infected area. Either its schistosomiasis condition and snail information or the harmful degree of schistosomiasis is at the top of our country. A large number of Schistosomiasis patients are 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 in Jianghan plain are both general and representative in our country. In recent years, the achievements of schistosomiasis control were remarkable in Hubei province,but outbreaks still occurred. Some efforts have to be made to achieve the goal of interrupting schistosomiasis transmission. Snails serve as the only intermediate hosts, whose distribution is strongly associated with the transmission of schistosomiasis, so elimination and control of snails has become the most important and effective way to detente the distribution of schistosomiasis in Hubei province. This paper analysed the relationship of Oncomelania＇s density with three kinds of land use, which are prone to breed Oncomelania, including bottomland, waterways and paddy. Firstly, the remote sensing images of Landsat TM of Jianghan plain in 2009 were preprocessed using ERDAS 9.2 and ENVI 4.7. On the basis of the previous few land use data, the land use change areas were extracted with vector similarity index by eCognition; then they were interpreted by visual interpretation, application of remote sensing indexes and establishment of classification rule sets. The classification result of the land use change areas was used to update the land use classification data in 2000.Then,the land use classification data in Jianghan plain in 2009 were obtained. Next,this paper sorted out materials of surveying and controlling Oncomelania and calculated Oncomelania＇s average density at the village level. Meanwhile, the Oncomelania＇s distribution vectogram in 2009 was drew in detail by ArcGIS software. With administrative village vectogram as base maps and with the corresponding international code as related field, and using Joins and Relates tool to connect above arranged Oncomelania＇s information table, the Oncomelania＇s database were established. The vectogram about Oncomelania＇s distribution and land use data were overlaid and displayed. Combined with the data from the field survey,it could draw a conclusion that Oncomelania were likely to breed on bottomland, waterways and paddy. Finally, the Oneomelania＇s density and the three land use ratio were analyzed by linear regression. The result showed that there was linear relationship between Oncomelania＇s density and the ratio of three kinds of land use. R2 of 0. 857 was obtained from the model. The conclusion is instructive and meaningful to estimate the Oncomelania＇s density by remote sensing images. Moreover,it may provide the Schistosomiasis prevention and control department with scientific reference to put forward a land use pattern of using land use reasonably and controlling Oncomelania.