论洞庭湖区钉螺孳生环境与生态灭螺防病

洞庭湖区的钉螺面积广布，血吸虫病流行，是我国血吸虫病流行最严重的地区之一，分析表明，血吸虫病是湖区的一大生态环境灾害；它的中间宿主钉螺孳生环境是入湖泥沙沉积恶性循环的结果，频繁的洪溃灾害，扩散了垸内钉螺；水利工程为钉螺的传播提供了多种途径，急需采取生态灭螺防病的科学对策。

On the Surviving Condition of Oncomelania hupensis in Dongting Lake Area and Epidemic Prevention by Ecological Methods

As one of the largest districts where the nail-snails ( Oncomelania hupensis )exist and distribute in China, the Dongting lake area is also the widest regions where schistosoma japonicum prevail seriously. Through adruous investigation in the areas where smail prevailed, some conclusions are drawn: (1) The nail snails and the schistosoma japonicum resulted have been endangering human beings' health, resources and the environment. (2) The prevalence of the nail snails is the direct result of the development of the nail snail's survival condition: suitable ecological enviornment, and frequent flooding in the Dongting Lake area, which benefits the nail snails to live and spread. Moreover, the water conservancy projects have provided the nail snails for ways of spreading, which aggravates the spreading of the nail snails. (3) As to methods to preventing the epedemic nail snails, some ecological measures should be taken, i.e. to restore the ecological system on the catchment scale, decreasing the in put discharge and deposit to the Dongting Lake; to develop intergrated ecological economy with high effieiency, destroying the surviving condition for snails; to utilize the grassland resources reasonably, cutting off the snail's spreading channels, etc.