These lengths were judged to be sufficient to estimate the condition of the adjacent river reach. Live trees apparently in the process of becoming debris, but not yet dislodged from the bank, were not included in the investigation. Piece length was measured from end of root mass or spar butt to spar top. Pieces less than 1.5 meters long were not recorded. Diameter was measured above the root flare or any abnormally large butt swelling, and at the spar top.
Some characteristics reflect debris history and potential to accumulate.
The presence or absence of branches is an indicator of length of time in the channel and the destructive forces exerted on the piece. Bark condition reflects abrasion and extent of decomposition, and may indicate how long the piece has been in the channel. Curved pieces of debris seem to be more likely to form intertwined jams. Root-mass condition is an indicator of the origin of a piece of debris and its exposure to abrasion and fluvial erosion. A root mass containing soil indicates relatively recent introduction into the channel.