New Search
Figure 2: Key components of the 240' Salmon Guidelines Area <br /> The following diagram (Figure-}j illustrates several of the terms that will be use <br /> remainder of this d thr <br /> <br /> . guide. oughout the <br /> j <br /> 1 w. • <br /> Ri Arian Corridor <br /> ~ <br /> '~,[.~.b~._ <br /> Top of ~ ~ Top of -~`T~ , <br /> I Bank Bank <br /> 5trea m . r <br /> ~ Arian Ch <br /> dip Area annef <br /> I Riparian Area <br /> Wetland <br /> (Right) <br /> Figure ~2. Cross-section of the stream channel, top of bank, and riparian area. The stream or river than <br /> the bed where a natural stream of water runs or may run; it is the long narrow depression sha ed b nel is <br /> p y the <br /> concentrated flow of a stream and covered continuously or periodically by water. For a given stream or river <br /> channel, the top of the bank is the highest point at which the bank meets the grade of the surroundin <br /> topography, characterized by an abrupt or noticeable change from a stee er g <br /> where natural conditions prevail, by a noticeable change from too a h grade to a less steep grade, and, <br /> and/or movement of the water to too a h not primarily shaped by they resencely shaped by the presence <br /> is the area of vegetation along the banks of a river, stream rese p of water. The riparian area ' <br /> width of the riparian area is often calculated as one or two "Potential Tree Heightsa (PTH) <br /> from thetowof he <br /> bank. A PTH is the average height of the dominant tree species along the stream banks at m ! <br /> aturity. Along the <br /> floor of the Willamette Valley, black cottonwood is usually the dominant tree species. Black co p l <br /> PTH of about 120 feet. Therefore, using the 1-2 PTH definition, the riparian area wo ttonwood has a j <br /> from the top of bank. For the ~~li'ns Salmon Guidelines Area GIS layer the 121d extend 120-240 feet i'. <br /> to define the extent of the Critical sirbzoncsub-area, while the area between 120 feet and 240 feet from to used <br /> bank defines the Influence strbzoncsub-area. p of <br /> For further assistance in identi <br /> components of the Salmon Guideline Area, contact the S~oea, Critical sub-area, or other <br /> Information. section), n Team (see Additional Sources of <br /> i <br /> i <br /> i <br /> i <br /> I <br /> 1 <br /> Guidelines for Salmon 4-19-04 , ; <br /> Page 9 <br /> <br />