Aim To study the relationship between the changes of ecology and environments and the transmission of Schistosomiasis japanica after the construction of the three gorges reservoir.Methods Based on predictive data supp...Aim To study the relationship between the changes of ecology and environments and the transmission of Schistosomiasis japanica after the construction of the three gorges reservoir.Methods Based on predictive data supplied by the Yangtze River Committee on Water Conservancy,of the changes of the water level and sediment in the middle and lower reaches of the Yangtze river after the dam construction, corresponding data were collected and mathematics model was extablished by field pilot studies. In order to understand the effects of changes of water level and sediment on the growth 4 distribution of Oncomelania hupensis which is the intermediate host of Schistosoma japonicum, field surveys and ecologically intimated experiments were done.The prevalence status and factors related to transmission were investigated by methods of epidemiology, geographical medicine and social medicine.Results 1 The Three Gorges Project is an integrated project in a large scale to exploit and improve the environments of the Yangtze River. It will have a profound effect on improving and accelerating China’s social and economic development. 2 Positive impact on control of Schistosomiasis after the construction of The Three Gorges Reservoir:After the dam construction, the decrease in the frequency of flooding in Yangtze River will be occurred which cease the diffusion of snails and decline the chances ofinfectionofhumanandlivestock. Snails habitats will be reduced in the flushed areas along the Yangtze River. Exploitation of beaches and delimination of snails will be benefited from the beach’s uplift in the flushed areas. And the floods that will be ahead of time in autumn will interfere the development of snails.3 Negative impact on control of Schistosomiasis after the construction of The Three Gorges Reservoir:The flushed beaches and migrator’s settlements in certain altitude may become snail habitats.The reservoir areas will become the potential transmission areas of Schistosomiasis due to diffusion of infectious resources and Onco展开更多
根据长武ETC全新世土壤剖面的测定分析,探讨了该地区全新世成壤环境演变过程,阐明了先周时代土壤特征及人类耕作对成壤过程的影响。研究结果表明,全新世早期气候温和干燥,沙尘暴明显减弱,风尘堆积速率降低,具有轻微生物风化成壤作用;对...根据长武ETC全新世土壤剖面的测定分析,探讨了该地区全新世成壤环境演变过程,阐明了先周时代土壤特征及人类耕作对成壤过程的影响。研究结果表明,全新世早期气候温和干燥,沙尘暴明显减弱,风尘堆积速率降低,具有轻微生物风化成壤作用;对应于全新世最适宜期,该地气候温暖湿润,生物风化成壤作用大于风尘堆积作用,为典型的黑垆土成壤期。从3 100 a B.P.开始,季风气候格局发生转变,气候干旱化,沙尘暴加剧,风尘堆积速率大于生物风化成壤速率,土壤资源自然退化,形成弱成壤层和黄土层,两层均属于全新世黄土L0。先周时期耕作层对应古土壤层的顶部,土壤具有典型的团粒结构。3 100 a B.P.时的季风转变导致的气候干旱化与土壤退化促使了游牧民族南迁和“古公迁岐”事件的发生。展开更多
文摘Aim To study the relationship between the changes of ecology and environments and the transmission of Schistosomiasis japanica after the construction of the three gorges reservoir.Methods Based on predictive data supplied by the Yangtze River Committee on Water Conservancy,of the changes of the water level and sediment in the middle and lower reaches of the Yangtze river after the dam construction, corresponding data were collected and mathematics model was extablished by field pilot studies. In order to understand the effects of changes of water level and sediment on the growth 4 distribution of Oncomelania hupensis which is the intermediate host of Schistosoma japonicum, field surveys and ecologically intimated experiments were done.The prevalence status and factors related to transmission were investigated by methods of epidemiology, geographical medicine and social medicine.Results 1 The Three Gorges Project is an integrated project in a large scale to exploit and improve the environments of the Yangtze River. It will have a profound effect on improving and accelerating China’s social and economic development. 2 Positive impact on control of Schistosomiasis after the construction of The Three Gorges Reservoir:After the dam construction, the decrease in the frequency of flooding in Yangtze River will be occurred which cease the diffusion of snails and decline the chances ofinfectionofhumanandlivestock. Snails habitats will be reduced in the flushed areas along the Yangtze River. Exploitation of beaches and delimination of snails will be benefited from the beach’s uplift in the flushed areas. And the floods that will be ahead of time in autumn will interfere the development of snails.3 Negative impact on control of Schistosomiasis after the construction of The Three Gorges Reservoir:The flushed beaches and migrator’s settlements in certain altitude may become snail habitats.The reservoir areas will become the potential transmission areas of Schistosomiasis due to diffusion of infectious resources and Onco
文摘根据长武ETC全新世土壤剖面的测定分析,探讨了该地区全新世成壤环境演变过程,阐明了先周时代土壤特征及人类耕作对成壤过程的影响。研究结果表明,全新世早期气候温和干燥,沙尘暴明显减弱,风尘堆积速率降低,具有轻微生物风化成壤作用;对应于全新世最适宜期,该地气候温暖湿润,生物风化成壤作用大于风尘堆积作用,为典型的黑垆土成壤期。从3 100 a B.P.开始,季风气候格局发生转变,气候干旱化,沙尘暴加剧,风尘堆积速率大于生物风化成壤速率,土壤资源自然退化,形成弱成壤层和黄土层,两层均属于全新世黄土L0。先周时期耕作层对应古土壤层的顶部,土壤具有典型的团粒结构。3 100 a B.P.时的季风转变导致的气候干旱化与土壤退化促使了游牧民族南迁和“古公迁岐”事件的发生。
