Author(s): J. L. M. P. De Lima; C. Canhoto
Linked Author(s):
Keywords: Stream water temperature; Warming system prototype; Whole-stream manipulative experiment
Abstract: The expected increase in mean global air temperature will be reflected in increasing water temperatures of streams. The objective of this paper is to describe a whole-stream manipulative experiment, focusing on the hydraulic design, to induce an increase in water temperature on a stream. The experiments took place from March 2010 to February 2012. A constant flow of stream water was controlled by a hydraulic setup consisting of: (i) a water intake and a transport system associated with a heating structure and (ii) a manipulated stream reach with two parallel channels (~22m long; ~1. 5m width) subdivided by a longitudinal barrier made of schist stones. One half channel of the study reach received heated water (~3oC above the other half), while the other half received water at stream temperature. A constant flow was controlled with weirs and valves on both halves installed in the tanks and upstream the study reach. A bypass channel guaranteed the drainage of the excess water not captured by the two parallel channels. The system maintained a steady flow while allowing natural variation in abiotic factors and was successfully used to evaluate the effects of warming on a stream structure and functioning.
Year: 2014