Introduction

This project demonstrates the many components of working with ArcView GIS software. Compiled is a complete set of GIS vector map themes, Digital Elevation Models (DEMS), Digital Raster Graphics (DRGs) and other GIS data for Gale Creek Watershed.

Watershed Location

Gale Creek Watershed is located in the northwestern corner of Oregon and is contained almost completely in Washington County. It is one of many large watersheds in the Tualatin River Basin. It is situated on the eastern side of the Coast Range Mountains.

General Geology

The oldest geologic materials in the Gales Creek Watershed and volcanic and sedimentary rocks formed during the Eocene and Oligocene ages of the Tertiary period. The volcanic rocks and mostly basaltic lavas and tufts, overlain by sedimentary rocks made up of shale, claystone, sandstone, and siltstone. There are 11 soil associations listed in the Natural Resources Concervation Service (NRCS) Soil Survey of Washington County. Soils in the Coast Range are well-drained silt loam and cobbly loam. The nearly level flood plains consists of young alluvium, silt, and clay deposits approximately 20 to 30 feet thick. The historic wetland areas have eight hydric soil types which are generally very deep, poorly drained, and have slow surface runoff. The entire watershed is underlain by sandstone 400 feet thick (Breuner).

Hydrologic Summary

The watershed has 10 subbasins and contains 17 tributaries. Streams are fed primarily by precipitation. Most streams in the low lying parts of the watershed have beenchannelized and wetland areas have been drained for agriculture use.

Conclusions

This project focused on finding and displaying various GIS data for Gales Creek Watershed. It included assembling DRG, DEM, DOQ, bedrock geology, precipitation, soils, vegetation (timber), streams and road themes in the form of our particular watershed.

References Cited

Breuner, Nancy. (1998). Gales Creek Watershed Assessment Project. Tualatin River

Watershed Council.

Gale Creek Watershed in Washington County, OregonPrepared by:

Pamela Monnette

ES 492: GIS Applications in Earth Science

The figure on the right represents the types of Timber in Gales Creek Watershed with the streams in the area overlain on top of it.

Physiography

The watershed ranges in elevation from a low of 159 ft. above sea level, at the confluence with the Tualatin River, to its highest point of 3,154 ft. The mainstem of Gales Creek is 23.5 miles long and flows in a southeasterly direction. Land designations promote the rural character of the watershed by limiting land uses to forestry, agriculture, scattered rural residences, and rural services. Almost two-thirds of the watershed is privately owned (Breuner).

Oregon CountiesSubbasins of Gale Creek Watershed

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Task Two: Oregon Counties

Legend

Tillamook County

Washington County

Pamela Monnette

OregonGale Creek Watershed

Timber and Vegetation

The watershed contains a mosaic of native and exotic plant species. The original forested uplands, most of which was logged 40 to 80 years ago or burned in two stand-replacing fires in 1933 and 1945, known as the Tillamook Burn, have been replaced with Douglas-fir forests which are intensively managed. Furthermore, black cottonwood, bigleaf maple, Oregon ash, vine maple and elderberry are the dominant plant species in the riparian zone of Gales Creek (Breuner).

The watershed is entirely within the Northwestern edge of Washington County, except for 2 small portions extending into Tillamook County.

Buxton56 - 125126 - 194195 - 263264 - 332333 - 401402 - 470471 - 539540 - 608609 - 677No Data

Cochran264 - 355356 - 446447 - 537538 - 628629 - 719720 - 810811 - 901902 - 992993 - 1083No Data

Forest Grove38 - 4748 - 5657 - 6566 - 7475 - 8384 - 9293 - 101102 - 110111 - 119No Data

Gale Creek47 - 102103 - 158159 - 214215 - 270271 - 326327 - 382383 - 438439 - 494495 - 550No Data

Laurel Wood34 - 8586 - 137138 - 188189 - 240241 - 291292 - 343344 - 394395 - 446447 - 498No Data

Scholls31 - 6162 - 9293 - 123124 - 154155 - 185186 - 216217 - 247248 - 278279 - 309No Data

Timber122 - 209210 - 297298 - 384385 - 472473 - 559560 - 647648 - 734735 - 822823 - 910No Data

Woods Point209 - 305306 - 401402 - 498499 - 594595 - 691692 - 787788 - 884885 - 980981 - 1077No Data

Roaring Creek87 - 194195 - 301302 - 409410 - 516517 - 624625 - 731732 - 839840 - 946947 - 1054No Data

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Quad Digital Elevation Model in feet

Pamela Monette

On the left is a Digital Elevation Model of all of the Quads that make up Gales Creek Watershed. The darkerareas represent higher elevations, while the lighter areas represent lowerelevations. D

EM

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Digital Orthophoto Quads for Gale Creek Watershed

Pamela Monnette

Digital Orthophotos of Gales Creek Watershed Quadrangels

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Qs

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Quad DRGs for Gale Creek Wateshed

Gale Creek Watershed boundary

Pamela Monnette

Legend

Cochran Timber Buxton

Woods Point Roaring Creek Gales Creek

Forest Grove Hillsboro

Laurel Wood Scholls

Here we see an image of digital raster graphics withan outline of the Gales CreekWatershed boundary overlain on top of the quads.

and

DR

Gs!

Streams

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Streams within Gale Creek Watershed Quadrangle Footprint

Pamela Monnette

Legend

Timber TypesMerchantable TimberBurned Areas re-stockingBurned Areas non re-stockNon-timber Areas

Streams

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Streams on VegetationTask 9H

Legend

Pamela Monnette

Climate

The climate with the watershed is marine-influence with an extended winter rainy season. Summers tend to be hot and dry with little rainfall. The Coast Range Mountains form the upper north and Western boundaries of the watershed, separating it from the Pacific Ocean to the west. The mountain slopes tend to be steep with high gradient streams.

This figure was achievedBy clipping a larger stream networkto the area of the Quadrangles thatGales Creek Watershed resides in.

60-7080-90

100-120

48-52

44-48

40-44

60-70

56-60

This is a figure displaying theprecipitation in inches annually received in Gales Creek Watershed.

Above is a figure showing the distribution of bedrockGeology within Gales Creek Watershed. The colorsAre represented by codes that correspond to differentTypes of rock. Overlain onto this theme, is a map ofMajor highways.

Bedrock Geology11241150117011732053207020712075207639947233724072421243512450125321258314660

Highways

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Roads on bedrockTask 9F

Legend

Pamela Monnette

Gales Creek Pictures