摘要：We evaluated two questions related to the use of permanent sites in evaluating stream attributes at the reach scale. 1) Are permanent sites more efficient than temporary sites in determining a change or trend? 2) How exact must permanent sites be relocated to improve sampling efficiency? We found that sample sizes necessary to detect a significant change for 13 of the 14 attributes were reduced by at least 40% if the sample design is based on permanent rather than temporary sites. The value of permanent sites increased with the increased precision of relocating that site.
