The conditions at the so-called plunge point, where the river inflow disappears beneath the surface of the reservoir, are especially difficult to define. 所谓汇入点，即该处河道入流在水库水面之下消失的那一点，其条件特别不容易定出。
The conditions at the so-called plunge point, where the river inflow disappears beneath the surface of the reservoir, are especially difficult to define. 所谓汇入点，即该处河道入流在水库水面之下消失的那一点，其条件特别不容易定出。
