Analysis and forecast of rat density in Three Gorges reservoir area in Yichang,Hubei by Grey Model(1997-2012)

Objective To explorer the rat density variation in Three Gorges reservoir area in Yichang,Hubei.Methods By establishing GM(1,1)model of rat density in Three Gorges reservoir area in Yichang city from 1997to 2012,to forecast the indoor and outdoor rat density from 2013to 2014.Results The predicted values of rat density showed slight downward trend from 2013to 2014in Three Gorges reservoir area in Yichang city.The fitted models are significant statistically.The indoor rat densities will be 1.55%and 1.45%,1.30%and 1.29%for outdoor from 2013to 2014.Conclusion With the environment changes in Yichang Three Gorges reservoir,the rat density and constitute were changed correspondingly.It is suggested that rat density surveillance should be strengthened for vector-borne diseases control and prevention.