Abstract:

Objective Objective To master the Oncomelania hupensis snail situation in wetlands surrounding reservoirs in hilly areas in Danling County，Sichuan Province，so as to provide the reference for improving the snail control in these areas. Methods Methods A medium?sized reservoir（Meiwan Reservoir）and a small?sized reservoir（Zhulinkan Reservoir）were chosen respectively，and the snail situation of the environments surrounding the reservoirs were investigated，the indexes such as the occurrence rate of frames with snails and the density of living snails at the upstream and downstream of the reservoirs as well as the surrounding en? vironments were calculated and compared. Meanwhile，the data of the snail situation of the adjacent villages in the irrigation dis? trict at the downstream of the reservoirs year by year were collected to analyze the variation trend. Results Results The Meiwan Reser? voir was located in the deep hill，the occurrence rate of frames with snails was 4.29%，the highest and average densities of living snails were 28.00 snails/0.1 m2 and 0.38 snails/0.1 m2 ，respectively. There was a statistically significant difference between the occurrence rates of frames with snails at the upstream and downstream，which were 0.17% and 22.16%，respectively（ χ2 = 1 267.40，P < 0.05），and the rate of spillway was the highest（51.69%） . The highest and average densities of living snails in the downstream were 7.00 and 656.10 times higher than those in the upstream respectively. The Zhulinkan Reservoir was located in the shallow hill，the occurrence rate of frames with snails was 17.29%，and the highest and average densities of the living snails were 38.00 snails/0.1 m2 and 0.61 snails/0.1 m2 ，respectively. There was a statistically significant difference between the occurrence rates of frames with snails at the upstream and the downstream，which were 12.95% and 50.92% respectively （χ2 = 194.68，P < 0.05），and the rate of spillway was the highest （65.74%） . The highest and average densities of living snails in the downstream were 5.43 and 10.00 times higher than those in the upstream respectively. After the construction of the two reser? voirs，the snail area in the irrigation districts of the adjacent villages at the downstream was 57.26% of that before and after the construction（398 030 m2 /695 160 m2 ） . The snail area showed a downward tendency with repeatedly rebound since the 1990s. Conclusions Conclusions The wetland surrounding the reservoir in hilly region is suitable for snail breeding，and the snail situation in the shallow hill is more serious than that in the deep hill. There exists a risk for the repeatability of snail situation in this type of area where the snails can easily diffuse.

Key words: Oncomelania hupensis； Hill； Reservoir； Wetland； Monitor； Danling County

摘要：

目的 目的 对丹棱县水库湿地螺情进行监测， 为该类地区钉螺控制提供依据。 方法 方法 选择该县中、 小型水库各1 座， 对水库周围各类环境螺情进行调查， 计算并比较两水库上下游以及各主要环境的有螺框出现率和活螺密度等指标。同时， 收集两水库下游邻村灌区逐年螺情资料， 分析螺情变化趋势。 结果 结果 梅湾水库地处深丘， 有螺框出现率为4.29%，活螺最高密度为28.00只/0.1 m2 、 平均密度为0.38只/0.1 m2 ； 上、 下游有螺框出现率分别为0.17%和22.16%， 差异有统计学意义 （χ2 = 1 267.40， P < 0.05）， 以溢洪道最高 （51.69%）； 下游活螺最高密度及平均密度分别是上游的7.00倍和656.10 倍。竹林坎水库地处浅丘， 有螺框出现率为17.29%， 活螺密度最高为38.00只/0.1 m2 、 平均密度0.61只/0.1 m2 ； 上、 下游有螺框出现率分别为12.95%和50.92%， 差异有统计学意义 （χ2 = 194.68， P < 0.05）， 以溢洪道最高 （65.74%）； 下游活螺密度最高和平均密度分别为上游的5.43倍和10.00倍。水库建成后， 两座水库下游邻村灌区历史有螺面积占整个修建前后的 57.26% （398 030 m2 /695 160 m2 ）； 从20世纪90年代开始， 下游邻村有螺面积呈曲线下降趋势， 期间曾多次回升。 结论 结论丘陵水库湿地适宜钉螺孳生， 且浅丘比深丘螺情更重。该类地区钉螺易扩散， 有螺情反复的风险。

关键词: 钉螺； 丘陵； 水库； 湿地； 监测； 丹棱县