river stage fluctuation

例句：

1. 1. The river stagefluctuations are a natural partof the ecosystem.
   河流阶段波动是生态系统的一部分。
2. 2. The scientists observed the river stagefluctuations during their research trip.
   科学家们在研究旅行中观察到了河流阶段波动。
3. 3.The river stage fluctuations can have significantimpacts on the local ecosystem.
   河流阶段波动对当地生态系统有重大影响。