High-resolution digital elevation model of lower Cowlitz and Toutle Rivers, adjacent to Mount St. Helens, Washington, based on an airborne lidar survey of October 2007
- More information: USGS Index Page
- Document: Delivery Report (481 kB pdf) Report by Watershed Sciences, Inc., under contract to USACE, on high-precision airborne lidar data collected October 22 through 27, 2007.
- Metadata: Metadata (16 kB txt)
- Read Me: Read Me (6 kB txt)
- Spatial Data:
- 1m DEM (830 MB zip) Digital-elevation data using bare-earth lidar data as 1-m resolution Esri grid files. Refer to the Readme and Metadata files for more information.
- 10m DEM (9.9 MB zip) Digital-elevation data using bare-earth lidar data as 10-m resolution Esri grid files. Refer to the Readme and Metadata files for more information.
- 1m hillshade (286.5 MB zip) 1-m resolution hillshade image with pyramids. Refer to the Readme and Metadata files for more information.
- Download citation as: RIS | Dublin Core
The lateral blast, debris avalanche, and lahars of the May 18th, 1980, eruption of Mount St. Helens, Washington, dramatically altered the surrounding landscape. Lava domes were extruded during the subsequent eruptive periods of 1980–1986 and 2004–2008. More than three decades after the emplacement of the 1980 debris avalanche, high sediment production persists in the Toutle River basin, which drains the northern and western flanks of the volcano. Because this sediment increases the risk of flooding to downstream communities on the Toutle and lower Cowlitz Rivers, the U.S. Army Corps of Engineers (USACE), under the direction of Congress to maintain an authorized level of flood protection, continues to monitor and mitigate excess sediment in North and South Fork Toutle River basins to help reduce this risk and to prevent sediment from clogging the shipping channel of the Columbia River. From October 22–27, 2007, Watershed Sciences, Inc., under contract to USACE, collected high-precision airborne lidar (light detection and ranging) data that cover 273 square kilometers (105 square miles) of lower Cowlitz and Toutle River tributaries from the Columbia River at Kelso, Washington, to upper North Fork Toutle River (below the volcano's edifice), including lower South Fork Toutle River. These data provide a digital dataset of the ground surface, including beneath forest cover. Such remotely sensed data can be used to develop sediment budgets and models of sediment erosion, transport, and deposition. The U.S. Geological Survey (USGS) used these lidar data to develop digital elevation models (DEMs) of the study area. DEMs are fundamental to monitoring natural hazards and studying volcanic landforms, fluvial and glacial geomorphology, and surface geology. Watershed Sciences, Inc., provided files in the LASer (LAS) format containing laser returns that had been filtered, classified, and georeferenced. The USGS produced a hydro-flattened DEM from ground-classified points at Castle and Coldwater Lakes. Final results averaged about two laser last-return points per square meter. As reported by Watershed Sciences, Inc., vertical accuracy is 10 centimeters (cm) at the 95-percent confidence interval on bare road surfaces; however, over natural terrain, USGS found vertical accuracy to be 10–50 cm. This USGS data series contains the bare-earth lidar data as 1- and 10-meter (m) resolution Esri grid files. Digital-elevation data can be downloaded (1m_DEM.zip and 10m_DEM.zip), as well as a 1-m resolution hillshade image with pyramids (1m_hillshade.zip). These geospatial data files require geographic information system (GIS) software for viewing.
|Publication Subtype||USGS Numbered Series|
|Title||High-resolution digital elevation model of lower Cowlitz and Toutle Rivers, adjacent to Mount St. Helens, Washington, based on an airborne lidar survey of October 2007|
|Series title||Data Series|
|Publisher||U.S. Geological Survey|
|Publisher location||Reston, VA|
|Contributing office(s)||Volcano Science Center|
|Description||Delivery Report: 19 p.; Readme; 1m DEM data; 10m DEM data; 1m hillshade image; Metadata|
|Other Geospatial||Cowlitz River, Mount St. Helens, Toutle River|
|Datum||North American Datum of 1983|
|Projection||Universal Transverse Mercator projection, Zone 10N|
|Online Only (Y/N)||Y|
|Additional Online Files (Y/N)||Y|
|Google Analytic Metrics||Metrics page|