Design of a paired-weir system for experimental manipulation of environmental flows in streams

摘要

Controlled in-stream flow manipulations are challenging but necessary to implement to assess the consequences of real-world flow alterations on aquatic ecosystems. We designed a double v-notch weir system, which was first prototype-tested in a laboratory flume and then in the field. The device diverted instantaneous flows proportionally in a robust way (e.g., 10 of flow in the stream main channel and 90 of flow into the diversion channel). We tested diversions systematically and evaluated how well flows matched our target flow-percentages. This is one of the first ecohydraulic structures designed and tested to experimentally manipulate environmental flows in small upland streams.