Deep Pools and Shallow Riffles: A Stretch of Water with Two Speeds

A rhythmic section of a stream. Riffles and pools alternate at regular intervals: in the riffles, the water is very shallow, the bottom is coarse gravel, the water surface is broken and whitish, and the sound is clear; in the pools, the water surface is smooth and dark green, almost silent, and large stones and shadows can be seen underwater. The transition between the two is very short. This alternation provides different environments needed by various organisms. Avoid: having a consistent water depth and flow velocity throughout the entire section, making the streambed a uniform surface, using a flat concrete bottom, or having a calm water surface from beginning to end.

Translated from Chinese by AI.

一段有節奏的溪流。每隔一段距離就交替出現:淺瀨的地方水很淺、底部是粗礫石、水面破碎泛白、聲音清楚;深潭的地方水面平滑深綠、幾乎沒有聲音、可以看到水下的大石與陰影。兩者之間的過渡很短。這個交替提供不同生物需要的不同環境。避免:讓整段水的深度與流速一致、把水底做成均勻的鋪面、使用平整的混凝土底、讓水面從頭到尾都是平靜的。