52
ERDC TR-04-1
active floodplain (Dunne and Leopold 1978), an important distinction to make if
one delineates the OHWM based on the bankfull stage. Relief above the active
channel is not a reliable measure, by itself, of whether a surface is isolated from
flooding, but in conjunction with several weathering features (e.g., rock varnish,
desert pavement) can provide strong evidence that a surface is a terrace, not an
active floodplain (Field and Pearthree 1997). These weathering features, as
discussed later, may prove to be reliable indicators of areas that are definitively
above the OHWM. These distinctions are important because large superfloods,
with the possibility of recurring under the current hydrologic regime, can create
terraces along dryland rivers (Schick 1974, Schick and Magid 1978).
Previous Page
