Introduction

The Kilchis Watershed is an important watershed that is mostly driven by the Kilchis River which flows West into the Tillamook Bay. The Kilchis Watershed is composed of 13 subbasins.

Watershed Location

The Kilchis Watershed is located North of Tillamook in Tillamook County, OR.

ConclusionsBy examining the Kilchis Watershed, using ArcGIS, it becomes clear to

observe specific spatial information regarding it’s boundaries, subbasins, vegetation, geology, roads, elevation, streams, wetlands, and precipitation in regards to this specific area. More rainfall occurs in areas of higher elevation, agriculture exists in the lowlands of the watershed which also happen to be made up of alluvium deposits, and that the roads follow the waterways in the watershed. The skills used in creating this poster include: the collection of GIS data from online sources, defining and transforming projection systems, clipping, dissolving, mosaicing, and displaying data, as well as problem solving and data transfer.

References Cited

http://www.oregon.gov/DAS/EISPD/GEO/alphalist.shtml

http://www.or.nrcs.usda.gov/pnw_soil/or_data.html

http://libweb.uoregon.edu/map/map_section/search.html

http://www.co.tillamook.or.us/gov/gis/default.htm

Kilchis Watershed of Tillamook County, OR

Prepared by:Spencer Helwig &Trevor Brown

ES 341

Physiography

The landscape present in the Kilchis watershed is mountainous terrain in the Coast Range, with the Kilchis River being the defining characteristic of the watershed. The watershed has a minimum watershed elevation of three feet and a maximum watershed elevation of 1,006 feet. The minimum slope is 0 decimal degrees and the maximum slope is 72.8 decimal degrees.

A variety of vegetation exists. The ones prominent existing are evergreen forests, red alder forests, mixed conifer and deciduous forests, and agriculture. This is reflected in the amount of rainfall the Kilchis Watershed receives over the year on average, with the peak rainfall of 200 inches.

General GeologyThe Kilchis Watershed has 4 different surface deposits: Qal, Tsd, Ttv, and

Ttvm. The Qal geocode stands for river alluvium deposits of Holocene age, the Tsd geocode stands for sedimentary rocks of Oligocene to upper Eocene age, the Ttv geocode stands for Tillamook volcanic rocks of Eocene age, and the Ttvm geocode stands for marine facies. The most common soil in the Kilchis Watershed is the Necanicum-Ascar-Klootchie Complex with 60 to 90% slopes.

Hydrologic Summary

The Kilchis Watershed covers a total drainage area of 168,153.9 sq. km, total width of 11.4km, and total length of 22.2km. The watershed is composed of 13 subbasins, and the average area of a subbasin covers 12.9 sq. km. The total number of streams in the watershed is 1,171, with the number of first order segments being 870 and the number of second order segments being 413. On average, there is one first order stream for every five sq. km.

Minimum Elevation (feet) 3Maximum Elevation (feet) 1006.2Minimum Slope (decimal degrees) 0Maximum Slope (decimal degrees) 72.8

Total Drainage Area (sq. meters) 168,153,967

Total Drainage Area (sq. km) 168.153967

Total Length of Watershed (sq. km) 22.2296Total Width of Watershed (sq. km) 11.375Total No. of Subbasins 13Average Area of Subbasins (sq. km) 12.93492

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Total No. of Stream Segments or Tributaries 1,717Total No. of First Order Stream Segments 870Total No. of Second Order Stream Segments 413First Order Stream Frequency (Total No. / Drainage Area)

1/5 sq. km