涵闸渠系钉螺截留系统(OSSS)模型实验研究初报

本实验根据流体力学和钉螺生态学理论,在配有循环水的玻璃水槽中,设计制作出由进水控制段、分离扩散段、沉降集中杀灭段、出流还原段组成的涵闸渠系钉螺截留系统(Oncomelania Stem-Stay System简称OSSS)模型。研究了改变流量、平均流速对钉螺截留的影响,分离扩散段对附叶钉螺的脱离率和截留率的影响。“采用模拟钉螺”对OSSS及其改良模型,在相同的水流条件下进行比较研究。结果表明:不加OSSS,钉螺和“模拟钉螺”全部冲向下游。而加OSSS,截留率均在98％以上,脱离率为97％。证明OSSS有良好的截留钉螺和使钉螺脱离载体的能力,而其中OSSS-1-3型较好,当相当原型流量0.93m~3/s,平均流速为15.4cm/S时,截留率可达99％。结果还表明OSSS具有不壅高水位,无需处理漂浮物,工程量小的优点。

EXPERIIMENTAL STUDY ON SNAIL-CONTROL OF IRRIGATION CANAL SYSTEM WITH OSSS MODEL

A hydraulic model of Oncomelania stem-stay system (OSSS) was set up by incorperating the silt engineering with the snail biology. The model consisted of the controlling section of inflow, the section for separation-diffusion, the section for deposition-collection-killing and the restoring section of outflow. The effects of altered current on the stem-stay rate of snail-sand effects of the seperation-diffusion section on the rates of seperation and stem-stay of snails were studied. The result showed that both snails and the "imitator"were rinsed down to downstream without the OSSS,while using the OSSS,the stem-stay was above 98% and seperation rate was 97%. It confirmed that the OSSS had strong capability to seperate the stem-stay snails from the silt carrier. By comparing several models, it was found that the model of OSSS-1-3 was the best. When the flow speed was 15- 4cm/s in the precipitating section, the rate of interception could reach 99%. The experiment showed that the OSSS had following advantages : 1. there was no need to block water to high level, 2. there was no need to eliminate floating debris, 3. the engineering project was smaller in comparing with others.