The progressive lag of sediment concentration with flood waves

Numerous investigations of suspended‐sediment discharge have shown that an increase in stream flow usually is accompanied by an increase in sediment concentration. The sediment‐concentration peak during a rise may precede, coincide with, or follow the water‐discharge peak. Observations on the Bighorn River in Wyoming and Montana show a progressive lag in peak concentration behind peak flow. The lag is most apparent when a single storm produces a flood wave that starts many miles upstream from the sampling sections.