This layer delineates mapping units derived and defined on the basis of its soil, landform, geology and vegetation characteristics. Soils Management Branch of th eDivision of Watershed Management. The average delineation size for each mapping unit is 50 to 600 acres. This data was originally mapped at the 1:24000 scale. Due to the reconnaissance nature of this survey, it lacks detail for use in high-intensity, small-area projects. These projects require addtional on-site study by various technical specialists, including soil scientists.
The dominant landtype of the mapping unit is described in the mapping unit description and identified by the same number as used for the mapping unit. Within the mapping unit, other landtypes occur. Those most commonly associated with the dominant landtype of the mapping unit are included in the descriptions as inclusions. These inclusions of other landtypes account for no more than 30 percent of the mapping unit. (for further descriptions of mapping unit symbology see SOIL RESOURCE INVENTORY" Willamette National Forest, Basic Soil Information and Interpretive Tables Many symbols shown on the maps have three digits and are called "Mapping Unit Complexes." These are mapping units used in areas where two or more defined mapping units are present in an arrangement too complex to separate at the one-inch per mile scale. The Legend of Complexes indicates the mapping unit components of the complex and the approximate percentage of each component.
ground condition
Internal feature number.(Source:
ESRI)
Feature geometry.(Source:
ESRI)
Area of feature in internal units squared.(Source:
ESRI)
Perimeter of feature in internal units.(Source:
ESRI)
Internal feature number.(Source:
ESRI)
User-defined feature number.(Source:
ESRI)
Soil resource inventory soil type
| Value | Definition |
|---|---|
| 0 |
Perpetual Snow, Ice, Rock Outcrop, and Talus |
| 1 |
Rock Outcrop, Andesites and Basalts |
| 2 |
rock Outcrop, Volcanic Breccias and Tuffs |
| 3 |
Talus, Rock Outcrop, Avalance Chutes, and Low-Site Timber |
| 4 |
Recent Volcanic Lava Flows |
| 5 |
Cinder Cones |
| 6 |
Wet Non-Forest Land |
| 7 |
Dry Non-Forest Land |
| 8 |
Steep Dissected Landforms from Volcanic Breccias and Tuffs |
| 9 |
Steep Dissected Landfrom, from Andesites, Basalts and Breccias |
| Other Soils |
For All Other Soils see Soil Resource Inventory-Willamette National Forest Document. |
Suitability for timber production
| Value | Definition |
|---|---|
| su |
Suited for timber production |
| un |
Unsuited for timber production |
Why unsuited. Unsuited & unmanageable landtype occur in 2 basic categories: those that are unregenerable & those where timber harvest will cause irreversible resource damage.
| Value | Definition |
|---|---|
| rd |
Regeneration difficulty - noncommercial forest land or non reforestable within 5 yrs. |
| vu |
Very unstable - landtypes where timber harvest will result in irreversible resource damage primarily because they are actively unstable or potentially highly unstable. |
Timber site class (productivity). Class limits correspond to height (site index) of Douglas fir at 100 yrs.
| Value | Definition |
|---|---|
| 1 |
Class I -- greater than 185 S.I. |
| 2 |
Class II -- 185 S.I. to 155 S.I. |
| 3 |
Class III -- 155 S.I. To 125 S.I. |
| 4 |
Class IV -- 125 S.I. To 95 S.I. |
| 5 Class V -- less than 95 S.I. |
[not provided] |
| >5 |
less productive than Class V |
Natural stability. This rating is based on the relative stability of the soil mapping units as they occur in the natural state. It includes any movement or loss other than surface erosion: includes slumps, slides, and all kinds of deep-seated failures.
| Value | Definition |
|---|---|
| I |
Very stable: no evidence of failure |
| I-II |
Very stable - stable |
| II |
Stable: Occasional failures are observed |
| II-III |
Stable - moderately stable |
| III |
Moderately stable: Several failures are observed |
| III-IV |
Moderately stable - unstable |
| IV |
Unstable: Many failures are observed |
| V |
Very unstable: Entire area shows evidence of recent & past failures |
Surface soil ersosion potential. This rating is based on expected losses of surface soil when all vegetative cover is removed. Evaluations of climate, slope, gradient & length, soil characteristics, hydrologic characteristics of the soil & bedrock material of each landtype unit are considered in making ratings.
| Value | Definition |
|---|---|
| mod |
Moderate |
| mod-sev |
moderate - severe |
| sev |
severe |
| sev-vs |
severe - very severe |
| sl |
slight |
| sl-mod |
slight - moderate |
Silt & clay sediment yield potential. Potential for water sedimentation antipollution from silt and clay particles carried in suspension following timber harvest, road construction or other activities. Factors considered in making ratings are soil texture & structure, drainage patterns, landform and climate.
| Value | Definition |
|---|---|
| H |
High |
| L |
Low |
| L-M |
Low - moderate |
| M |
Moderate |
| M-H |
Moderate - high |
Water yield class. Indication of rate & amount of water yield expected from each soil.
| Value | Definition |
|---|---|
| I |
Class I: High water detention storage capacity & low rate of runoff. |
| I-II |
Class I-II |
| II |
Class II: Moderate water detention storage capacity & moderate rate of runoff. |
| II-III |
Class II- III |
| III |
Class III: Low water detention storage capacity & high rate of runoff. |
Shallow soil types.
| Value | Definition |
|---|---|
| S |
Shallow |
| SC |
Shallow complex |
4431 Highway 20
For natural resource management.
Metadata imported.
Unknown
Unknown
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Neither the United States Government nor any of its employees make any warranty, expressed or implied, including the warranties of merchantability and fitness for a particular purpose, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. The United States Government is not responsible for the contents of any off site pages referenced.
Data format: |
in format ARCE Size: 15.148 |
|---|---|
Media you can order: |
CD_ROM, 8 mm cartridge tape (format tar format (Unix), ISO 9660) |
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