Maximum entropy model versus remote sensing-based methods for extract-ing Oncomelania hupensis snail habitats / 中国血吸虫病防治杂志

ABSTRACT

Objective To explore the technique of maximum entropy model for extracting Oncomelania hupensis snail habi?tats in Poyang Lake zone. Methods The information of snail habitats and related environment factors collected in Poyang Lake zone were integrated to set up the maximum entropy based species model and generate snail habitats distribution map. Two Land?sat 7 ETM+remote sensing images of both wet and drought seasons in Poyang Lake zone were obtained,where the two indices of modified normalized difference water index(MNDWI)and normalized difference vegetation index(NDVI)were applied to ex?tract snail habitats. The ROC curve,sensitivities and specificities were applied to assess their results. Furthermore,the impor?tance of the variables for snail habitats was analyzed by using Jackknife approach. Results The evaluation results showed that the area under receiver operating characteristic curve(AUC)of testing data by the remote sensing?based method was only 0.56, and the sensitivity and specificity were 0.23 and 0.89 respectively. Nevertheless,those indices above?mentioned of maximum en?tropy model were 0.876,0.89 and 0.74 respectively. The main concentration of snail habitats in Poyang Lake zone covered the northeast part of Yongxiu County,northwest of Yugan County,southwest of Poyang County and middle of Xinjian County,and the elevation was the most important environment variable affecting the distribution of snails,and the next was land surface tem?perature(LST). Conclusions The maximum entropy model is more reliable and accurate than the remote sensing?based meth?od for the sake of extracting snail habitats,which has certain guiding significance for the relevant departments to carry out mea?sures to prevent and control high?risk snail habitats.