The middle layer water intake is one of main engineering measures for intercepting oncomelania snails, and it is a key structure for preventing snails dispersion through sluice gates.

• 摘要中层取水是防止钉螺通过涵闸引水扩散的主要工程措施之一，在长江流域血吸虫病疫区得到了较广泛的应用；