Oregon Department of Geology and Mineral Industries, 2009, 45122-CS-1_Landslide_Deposits: DOGAMI Interpretive Map Series 26, Oregon Department of Geology and Mineral Industries, Portland, Oregon, USA.Online Links:
,.Online Links:
This is a Vector data set. It contains the following vector data types (SDTS terminology):
The map projection used is Lambert Conformal Conic.
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest 0.000000
Ordinates (y-coordinates) are specified to the nearest 0.000000
Planar coordinates are specified in international feet
The horizontal datum used is D_North_American_1983_HARN.
The ellipsoid used is Geodetic Reference System 80.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257222.
Sequential unique whole numbers that are automatically generated.
Coordinates defining the features.
William J. Burns and Ian P. Madin
971-673-1538 (voice)
971-673-1562 (FAX)
bill.burns@dogami.state.or.us
The landslide inventory is one of the essential data layers used to delineate regional landslide susceptibility. This landslide inventory is not regulatory, and revisions can happen when new information regarding landslides is found or future (new) landslides occur. Therefore, it is possible that landslides within the map area were not identified or occurred after the map was prepared.
This inventory map was prepared by following the Protocol for Inventory Mapping of Landslide Deposits from Light Detection and Ranging (Lidar) Imagery developed by Burns and Madin (2009). The three primary tasks included compilation of previously mapped landslides (including review of SP-34 (Hofmeister, 2000) and SLIDO (Burns and others, 2008)), lidar-based morphologic mapping of landslide features, and review of aerial photographs. Landslides identified by these methods were digitally compiled into a GIS database at varying scales. The recommended map scale for this data is 1:8,000 as displayed on this map. Each landslide was also attributed with classifications for activity, depth of failure, movement type, and confidence of interpretation. The landslide data is displayed on top of a base map that consists of an aerial photograph (orthorectified) overlain on the lidar-derived hillshade image.
This landslide inventory map is intended to provide users with basic information regarding landslides within the quadrangle. The geologic, terrain, and climatic conditions that led to slope failures in the past may provide clues to the locations and conditions of future slope failures, and it is intended that this map will provide useful information to develop regional landslide susceptibility maps, guide site-specific investigations for future developments, assist in regional planning, and mitigation of existing landslides.
Data sources used in this process:
Data sources used in this process:
Data sources used in this process:
Oregon Department of Geology and Mineral Industries, 2009, DOGAMI Special Paper 42, Protocol for Inventory Mapping of Landslide Deposits from Light Detection and Ranging (Lidar) Imagery: DOGAMI Special Paper 42, Oregon Department of Geology and Mineral Industries, Portland, Oregon.
CONFIDENCE OF INTERPRETATION: Each landslide should be classified according to a "confidence" that the mapper assigns based on the likelihood that the landslide actually exists. Landslides are mapped on the basis of characteristic morphology, and the confidence of the interpretation is based on the visual strength of the morphologies. As a landslide ages, after its most recent movement, weathering (primarily through erosion) degrades the morphologies produced by landsliding. With time, landslide morphologies may become so subtle that they resemble morphologies produced by geologic processes and conditions unrelated to landsliding. Some landslides have several different types of morphologies associated with them. A good way to define certainty is through a simple point system (see table below) associated with these features. The point system used is based on a ranking of four primary landslide features with a ranking of 0 to 10 points per feature. For example, if during mapping, the head scarp and toe of a landslide were identifiable and had very strong visual strength, the mapper would apply 10 points for the head scarp and 10 points for the toe equaling 20 points, which would be associated with a moderate certainty of identification.
Are there legal restrictions on access or use of the data?
- Access_Constraints:
- This map depicts an inventory of existing landslides based on published and unpublished reports and interpretation of topography derived from lidar data and air photos. The inventory was created following the protocol defined by Burns and Madin (2009). This map cannot serve as a substitute for site-specific investigations by qualified practitioners. Site-specific data may give results that differ from those shown on this map.
- Use_Constraints:
- Restrictions and legal prerequisites for using the data set after use is granted. These include any access constraints applied to assure the protection of privacy or intellectual property, and any special restrictions or limitations on using the data set. The maps cannot serve as a substitute for site-specific investigations by qualified practitioners. Site-specific data may give results that differ from those shown on the maps.
503-872-2750 (voice)
971-673-1562 (FAX)
don.haines@dogami.state.or.us
Spatial data files available in shape file (.shp) format (ESRI).
Although these data have been processed successfully on a computer system at the Oregon Department of Geology and Mineral Industries (DOGAMI), no warranty expressed or implied is made regarding the accuracy or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. It is strongly recommended that these data are directly acquired from DOGAMI, and not indirectly through other sources which may have changed the data in some way. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with these data. The Oregon Department of Geology and Mineral Industries shall not be held liable for improper or incorrect use of the data described and/or contained herein.
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One week
Geographic Information System software
971-673-1538 (voice)
971-673-1562 (FAX)
bill.burns@dogami.state.or.us