[Classification study on the marshland in endemic areas of Schistosoma japonicum using satellite TM image data].
OBJECTIVE
To create a land cover map of the marshland region of Schistosoma Japonicum using satellite TM data from Chayegang, Jiangxi Province.


METHODS
Satellite data of three TM bands, namely TM3, TM4 and TM5, were selected to be used in classification study with Principal Components Analysis. Then TM satellite images were applied to false color composite and unsupervised classification with computer software to manage the TM data. Finally the resulting clusters were identified by undertaking site visits and a systematic sampling snail survey was also carried out in the study area in April, 2000.


RESULTS
Three land cover classes were generated, including class 1, the carex zone that is both the dominant vegetation and main snail habitats of the study area. Based on the snail survey in the spring of 2000, the live snail density and infectious snail density of the carex zone were 2.51/0.11 m2 and 0.006 9/0.11 m2, respectively. The infection rate of the snail was 0.28%. No snail was found in land cover class 3, the mixed vegetation, because the altitude of this area is either above 17 m or under 14 m and therefore the vegetation in this area is unsuitable for snails to survive.


CONCLUSIONS
Remote sensing can contribute the study on the distribution of snail habitats and become a promising epidemiological study method for schistosomiasis and other ecological diseases.
Lin
T
T
Department of Epidemiology, School of Public Health, Fudan University, Shanghai 200032, China.
Jiang
Q
Q
Lin
D
D
D000818:Animals; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D003952:Diagnostic Imaging; D019353:Endemic Diseases; D004777:Environment; D017215:Satellite Communications / Q000295:instrumentation*; D012549:Schistosoma japonicum / Q000145:classification* / Q000254:growth & development; D012552:Schistosomiasis / Q000453:epidemiology*