Abstract: As some traditional water conservancy measures for schistosomiasis control (settling basin for oncomelania snail, and middle layer water intake projects) are restricted by a variety of conditions, it is imperative to conduct research on new measures of schistosomiasis control. In this research, vortex basin for oncomelania was developed based on the principles of desilting funnel, and model experiment was carried out to research the flow characteristics and trap efficiency of oncomelania by the vortex basin. Results show that as flow rate increases, the flow velocity and turbulence intensity increases. The tangential velocity decreases by moving from the center of the model towards sidewall along radial direction and by moving from the bottom of model to water surface along vertical direction. Large vertical velocity is found near the edge of deflector caused by the compress of deflector. Radial velocity at the inner edge is larger than that in outer regions. Vertical turbulence intensity in middle and upper part of flow is higher than that in low layer. Under different flow rates, a certain number of oncomelania snails are fed into the model and it is observed that the trap efficiency reaches 100%. It shows that vortex basin for oncomelania is an effective engineering measure.

Key words: schistosomiasis control, vortex basin for oncomelania, model experiment, flow structure, trap efficiency