Gao Jian-chuan, Zhou Yi-biao, Li Lin-han, Wu Jin-yi, Zheng Sheng-bang, Song Xiu-xia, He Zhong, Cai Bin, You Jia-bian, Jiang Qing-wu
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi. 2015 Jun;27(3):302-5.
To study the reasons of natural death of Oncomelania hupensis snails by comparing the differences of the indicator days covered with water (DCW) in snail marshland and non-snail marshland around the build of Three Gorges Dam in Eastern Dongting Lake areas.
Two marshlands were selected, one was a non-snail marshland (Qianliang Lake) and another was a snail marshland (Junshan Park). The measuring points were set through the mechanical sampling. The snails and elevation of the points were surveyed, and the data of the water levels from the hydrological station were collected, and then DCWs were calculated.
From 1995 to 2013, DCWs of the marshland of natural death of snails were all more than that of the snail marshland (P < 0.01). In Qianliang Lake marshland, the difference between DCW before natural death and DCW from natural death until the dam was not significant (P = 0.23), while DCWs of the two stages both were more than that after the dam (P1 = 0.045, P2 = 0.002). Before the build of the dam, DCW of the Qianliang Lake marshland of natural death of snails was more than that after the build of the dam (P = 0.013), and there was the same situation in Junshan Park marshland (P = 0.005). The relationship between snail density and DCW was not significant in Junshan Park marshland (r(s) = 0.008, P = 0.914), and the reference range of DCW of all the measuring points was 76-251 days.
In the eastern Dongting Lake district, the build of Three Gorges Dam and DCW may be not the direct factors affecting the natural death of snails and the latter may change the distribution of snails.
通过比较三峡大坝建成前后东洞庭湖地区有螺洲滩和无螺洲滩的淹水指标天数（DCW）差异，研究钉螺自然死亡原因。
选取两块洲滩，一块为无螺洲滩（钱粮湖），另一块为有螺洲滩（君山公园）。通过机械抽样设置测量点。调查测量点的钉螺及高程，收集水文站水位数据，然后计算淹水指标天数。
1995年至2013年，钉螺自然死亡洲滩的淹水指标天数均高于有螺洲滩（P<0.01）。在钱粮湖洲滩，自然死亡前的淹水指标天数与自然死亡至建坝后的淹水指标天数差异不显著（P = 0.23），而两个阶段的淹水指标天数均高于建坝后（P1 = 0.045，P2 = 0.002）。建坝前，钱粮湖钉螺自然死亡洲滩的淹水指标天数高于建坝后（P = 0.013），君山公园洲滩也有同样情况（P = 0.005）。君山公园洲滩钉螺密度与淹水指标天数的关系不显著（r(s) = 0.008，P = 0.914），所有测量点淹水指标天数的参考范围为76 - 251天。
在东洞庭湖地区，三峡大坝的建成和淹水指标天数可能不是影响钉螺自然死亡的直接因素，后者可能改变钉螺分布。
