Application of Landsatª²5 TM to analyze the change of vegetation quantity in Jicheng in the areas of ¡°breaking dikes or opening sluice for waterstore¡± in Dongting Lake

    SAI Xiaoª²Yong, ZHANG Zhiª²Ying, YAN Yongª²Ping, CAI Kaiª²Ping, LI Yueª²Sheng, ZHOU Xiaoª²Nong, XU Deª²Zhong

    1Department of Epidemiology, School of Preventive Medicine, Fourth Military Medical University, Xi¬ðan 710033, China, 2Hunan Institute of Antiª²epidemic of Schistosomiasis,Yueyang 414000, China, 3Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai 200032, China

    ¡¾Abstract¡¿ AIM: To study the change of vegetation quantity in Jicheng in the areas of ¡°breaking dikes or opening sluice for waterstore¡± (BDOSW) in Dongting Lake and the effect of the policy on the prevention of. schistosomiasis. METHODS: The area of Jicheng, extracted from Landsatª²5 TM images, was classified into 23 different categories based on different normalized difference vegetation index (NDVI) at the race of 10, and 11 categories were compared. RESULTS: NDVI of 6 out of the 11 categories after ¡°BDOSW¡± was higher than that before ¡°BDOSW¡± ( 54.54%). The areas of the 6 categories before ¡°BDOSW¡± and after ¡°BDOSW¡± accounted for 50.36% and 52.30% of the total area respectively. CONCLUSION: Remote sensing images of Landsatª²5 TM can be applied to analyze the impact of the policy of ¡°BDOSW¡± on ecological environment. Areas of some categories in Jicheng, for example, 121ª²160, 171ª²180 and 201ª²210 have increased after ¡°BDOSW¡±, and the effect on the prevention of schistosomiasis needs further study. ......