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Wetland polygons includes all wetlands greater than 1/10 acre within Creswell study area.Wetlands were coded sequentially with unique numbers, generally from north to south in the study area. Newly coded wetlands that extended beyond the study area boundary were digitized to reflect only the area within the study limits. Wetlands on file with DSL are identified with their existing delineation/determination number such as WD 2008-0485. In many cases, multiple wetlands were delineated at one time and have the same DSL file number. To create unique codes for each wetland for the OFWAM assessment, the delineation number was used in combination with a unique number such as WD2008-0485-1, -2. Each DSL wetland delineation within the study area was field verified and edited if the current size was different from the recorded size. Previously delineated or determined DSL wetland polygons extending beyond the study area with no size change were left as is. If a DSL wetland no longer existed it was deleted from the wetland polygon layer.If a wetland was bisected by a road or other feature but had a hydrologic connection with other sections of wetland; the wetland numeric code was given a letter, such as 8a, 8b to indicate that both polygons were part of the same assessment unit for OFWAM. If a wetland contained more than one Cowardin class of 0.25 acre or more, another polygon was drawn to represent this on a map. Cowardin classes are differentiated by shading type.All field data were collected and recorded using Trimble Yuma, Global Positioning System/Geographic Information System(GPS/GIS) data recorders. Aerial imagery and shapefiles of the study area were loaded onto the units for reference in the field. The GPS/GIS units enabled field crews to digitize wetland boundaries in ArcPad; edit existing wetland boundaries as necessary; map probable wetlands, artificial wetlands and locations of sample plots, and map streams. After the field work, data were uploaded onto a desktop computer for viewing and final editing. Data are intended for planning purposes only. |