ECOLOGICAL DESIGN OF IRRIGATION CANALS FOR SNAIL CONTROL.

The snail hosts of schistosomiasis have found ideal conditions for rapid colonization in many irrigation and drainage canal systems. By studying the hydrodynamic aspects of snail dislodgment it may be possible to devise a control method based on engineering the snail's microenvironment. For Australorbis glabratus, a velocity exceeding 33 cm/sec at shell height produces a hydrodynamic drag force sufficient to dislodge the snail from its position on the solid boundary of a canal.