Tags
Same unique code assigned by data steward to each landslide polygon in database
DOGAMI
Landslide scarp flanks polygons
DOGAMI Special Paper 42
This feature class represents polygons that delineate the head scarps and scarp flanks. These head scarps or uppermost scarps in many cases expose the primary failure plane (surface of rupture) and flanks or shear zones.
This data set is an inventory of mapped landslide scarp flanks in the Douglas County study area. This inventory is not regulatory, and revisions can happen when new information regarding landslides is found or when future (new) landslides occur. The landslide inventory is intended to provide users with basic information regarding landslides. The geologic, terrain, and climatic conditions that led to landslides in the past may provide clues to the locations and conditions of future landslides, and it is intended that this data will provide useful information to develop regional landslide susceptibility maps, to guide site-specific investigations for future developments, and to assist in regional planning and mitigation of existing landslides.
Publication
None
REPORT DATA: This product is for informational purposes and may not have been prepared for or be suitable for legal, engineering, or surveying purposes. Users of this information should review or consult the primary data and information sources to ascertain the usability of the information. This publication cannot substitute for site-specific investigations by qualified practitioners. Site-specific data may give results that differ from the results shown in the publication. See the accompanying text report for more details on the limitations of the methods and data used to prepare this publication.
When contacting DOGAMI about this data set, please reference the data set title or other identifying information in your correspondence. DOGAMI publications can be downloaded from http://www.oregongeology.org
The project described in this publication was supported in part by Federal Emergency Management Agency grant HMGP 4258 8-F.
All field values were checked for consistency with the domains listed in the Protocol for Inventory Mapping of Landslide Deposits from Light Detection and Ranging (lidar) Imagery. This check was a general attribute check. When necessary the field UNIQUE_ID is visually checked to have a matching unique ID in the Landslide Deposits feature class. This is a check for consistency between feature classes.
The Scarp Flanks feature class is a complete compilation of all landslide scarp flank polygons within the study area for coastal Douglas County; with the exceptions of landslides that are smaller than 100 square meters (1,075 square feet) which may not be identified due to the resolution of the lidar data and air photos used in this project area. Only deposits created using DOGAMI Special Paper 42, lidar-based methods will have their head scarps mapped.
The line work was captured by heads up digitizing at several different scales; 1:24,000 (the native scale of standard printed 7.5-minute topographic quadrangles), 1:10,000, and 1:4,000. All lines were relocated at a scale of 1:4,000 to ensure that all spatial data (lines) have been mapped consistently. While the protocol recommends data use at a map scale of 1:8,000, and the geodatabase contains data at 1:8,000 or better, for representation purposes the data have been visualized on the map plate at 1:32,000. Base map used for digitization was DOGAMI’s bare earth lidar. Lidar data quality requires that the average departure from planarity within any 10 meters by 10 meters area shall be no greater than 5 cm. However the accuracy will still vary with the skill and care of the individual mapper.
Maximum error calculated from the 1:8000 scale horizontal positional accuracy error.
For a detailed description of scarp flanks creation methodology, refer to DOGAMI SP-42.
When contacting DOGAMI about this data set, please reference the data set title or other identifying information in your correspondence. DOGAMI publications can be downloaded from http://www.oregongeology.org
Landslide scarp flanks polygons
DOGAMI Special Paper 42
When contacting DOGAMI about this data set, please reference the data set title or other identifying information in your correspondence. DOGAMI publications can be downloaded from http://www.oregongeology.org
Although these data have been processed successfully on a computer system at the Oregon Department of Geology and Mineral Industries, no warranty expressed or implied is made by DOGAMI regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty.
When contacting DOGAMI about this data set, please reference the data set title or other identifying information in your correspondence. DOGAMI publications can be downloaded from http://www.oregongeology.org