[Prediction of the spatial distribution of Oncomelania snails in marshland of Jiangning County using the Ordinary Kriging].
OBJECTIVE
To explore the methods to predict the distribution of Oncomelania hupensis in the marshland of Jiangning County.


METHODS
Semi-variogram was used to analyze the spatial autocorrelation of snails' distribution in the marshland of Jiangning using the Arcview8.1. A prediction map for the snails' distribution was established using the Ordinary Kriging and evaluated using the cross-validation.


RESULTS
Analysis showed that the distribution of alive snails in the marshland of Jiangning in the year 2000 was auto-correlated in spatial. The semi-variogram model which was spherical demonstrated that the variation of alive snails in spatial were related with distance apart when the distance was less than 0.0301. The prediction map of the snail distribution in the marshland of Jiangning was established based on the semi-variogram using the Ordinary Kriging. The cross-validation showed that the prediction map could estimate the distribution of snails in the marshland of Jiangning correctly. And the determinant coefficient for the prediction model was 0.973.


CONCLUSIONS
It is feasible to predict the snail distribution in the marshland of Jiangning County by using Ordinary Kringing and data from the surveillance spot.
Zhang
Zhi-ying
ZY
Department of Epidemiology, the Fourth Military Medical University, Xi'an 710032, China.
Xu
De-zhong
DZ
Peng
Hua
H
Zhou
Yun
Y
Zhang
Bo
B
Liu
Shi-jun
SJ
Zhou
Xiao-nong
XN
Gong
Zi-li
ZL
D000818:Animals; D001947:Breeding; D002681:China / Q000453:epidemiology; D004199:Disease Vectors; D004463:Ecology; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D012549:Schistosoma japonicum / Q000254:growth & development*; D012554:Schistosomiasis japonica / Q000453:epidemiology / Q000635:transmission*; D012621:Seasons; D012908:Snails / Q000254:growth & development / Q000469:parasitology* / Q000502:physiology*