Abstract
[Objective]Schistosomiasis japonica is a zoonotic parasitic disease caused by Schistosoma japonicum.As its sole intermediate host,the distribution pattern of Oncomelania hupensis snails is critical for disease control.This study aims to investigate the spatiotemporal trends of snail habitats,their responses to environmental factors,and the spatial distribution of future high-risk areas,thereby providing scientific support and decision-making refer-ences for identifying snail risk zones and preventing schistosomiasis in Wuhan City.[Methods]Based on spring snail survey data from Wuhan City between 2014 and 2023,remote sensing techniques were utilized to construct and extract a Vegetation Suitability Index(VSI),integrating the median membership of NDVI,textural homogenei-ty,patch scale,and edge density.Concurrently,environmental factors were acquired,including the Normalized Difference Vegetation Index(NDVI),Land Surface Temperature(LST),Water Incidence Frequency(WIF),Temperature(TEMP),Precipitation(PREC),Soil Moisture(SM),and Distance to Water(DIS).The spatio-temporal evolution of snail distribution was systematically analyzed,alongside the relationship between snail density and primary environmental factors.Spatial clustering and variations in cold/hotspot areas were evaluated.Finally,an XGBoost model was employed to predict snail habitat risk zones.[Results](1)From 2014 to 2023,both the snail-infested area and the density of live snails in Wuhan exhibited a fluctuating downward trend.The snail-infested area decreased from 43.675 7 million m2 in 2014 to 26.564 3 million m2 in 2023,with an average annual reduction of approximately 4.2％.The density of live snails declined from 0.061 snails per 0.11 m2 in 2014 to 0.036 snails per 0.11 m2 in 2023.(2)Over the past decade,snail density was spatially clustered mainly along the Fuhe River,the Yangtze River,and the Tongshun River,demonstrating significant spatial aggregation.The dynamic evolution of snail habitats varied distinctly across different river basins.The snail-infested area in the Fuhe River basin shrank substantially;the Yangtze River basin showed an overall fluctuating downward trend;whereas the Tongshun River basin experienced a rebounding growth,becoming the core area for subsequent snail expansion.(3)Correlation a-nalysis indicated that moisture-related factors had the most prominent impact on snail density(SM,WIF,and PREC showed moderate positive correlations).The improved VSI provided more effective supplementary explana-tions than NDVI alone,while the correlations with LST,TEMP,and DIS were generally weak.Based on these find-ings,a simplified factor model(SM,WIF,PREC,VSI)achieved a higher R2 under identical evaluation condi-tions without increasing errors compared to the full-factor model,indicating that a few key factors are sufficient to support snail density prediction and risk zoning.[Conclusions](1)The snail density risk zoning map,construc-ted based on model-predicted values,reveals that future high-risk areas are primarily distributed along the Fuhe River,Tongshun River,and Zhuru River.These areas are highly consistent with historical hotspots and may serve as key regions for snail density rebound or expansion.(2)It is recommended to prioritize snail eradication and eco-logical remediation in high-risk areas,strengthen monitoring,early warning,and risk assessments to promptly iden-tify and mitigate hazards,and enhance patrol management in seasonal waterlogged areas,agricultural irrigation ca-nals,and abandoned wetlands to prevent covert snail diffusion and habitat revival.These findings provide a basis for targeted schistosomiasis control in key river basins and offer technical support for snail monitoring and ecological regulation around water conservancy projects.关键词
钉螺/遥感技术/环境因子/长时间序列/武汉市Key words
oncomelania snails/remote sensing/environmental factors/long-term series/Wuhan City分类
医药卫生
