WorldCat Identities

Sobieszczyk, Steven

Works: 6 works in 7 publications in 1 language and 763 library holdings
Roles: Author
Publication Timeline
Most widely held works by Steven Sobieszczyk
Major turbidity events in the North Santiam River basin, Oregon, water years 1999-2004 by Steven Sobieszczyk( )

1 edition published in 2007 in English and held by 262 WorldCat member libraries worldwide

Analysis of geomorphic and hydrologic characteristics of Mount Jefferson debris flow, Oregon, November 6, 2006 by Steven Sobieszczyk( )

1 edition published in 2008 in English and held by 259 WorldCat member libraries worldwide

On November 6, 2006, a rocky debris flow surged off the western slopes of Mount Jefferson into the drainage basins of Milk and Pamelia Creeks in Oregon. This debris flow was not a singular event, but rather a series of surges of both debris and flooding throughout the day. The event began during a severe storm that brought warm temperatures and heavy rainfall to the Pacific Northwest. Precipitation measurements near Mount Jefferson at Marion Forks and Santiam Junction showed that more than 16.1 centimeters of precipitation fell the week leading up to the event, including an additional 20.1 centimeters falling during the 2 days afterward. The flooding associated with the debris flow sent an estimated 15,500 to 21,000 metric tons, or 9,800 to 13,000 cubic meters, of suspended sediment downstream, increasing turbidity in the North Santiam River above Detroit Lake to an estimated 35,000 to 55,000 Formazin Nephelometric Units. The debris flow started small as rock and ice calved off an upper valley snowfield, but added volume as it eroded weakly consolidated deposits from previous debris flows, pyroclastic flows, and glacial moraines. Mud run-up markings on trees indicated that the flood stage of this event reached depths of at least 2.4 meters. Velocity calculations indicate that different surges of debris flow and flooding reached 3.9 meters per second. The debris flow reworked and deposited material ranging in size from sand to coarse boulders over a 0.1 square kilometer area, while flooding and scouring as much as 0.45 square kilometer. Based on cross-sectional transect measurements recreating pre-event topography and other field measurements, the total volume of the deposit ranged from 100,000 to 240,000 cubic meters
Organic matters : investigating the sources, transport, and fate of organic matter in Fanno Creek, Oregon by Steven Sobieszczyk( )

2 editions published between 2007 and 2015 in English and held by 237 WorldCat member libraries worldwide

Major turbidity events in the North Santiam River basin, Oregon, water years 1999-2004 by Steven Sobieszczyk( Book )

1 edition published in 2007 in English and held by 3 WorldCat member libraries worldwide

Using turbidity monitoring and LiDAR-derived imagery to investigate sources of suspended sediment in the Little North Santiam River Basin, Oregon, winter 2009-2010 by Steven Sobieszczyk( )

1 edition published in 2010 in English and held by 1 WorldCat member library worldwide

The Little North Santiam River Basin is a 111-square mile watershed located in the Cascade Range of western Oregon. The Little North Santiam River is a major tributary to the North Santiam River, which is the primary source of drinking water for Salem, Oregon and surrounding communities. Consequently, water quality conditions in the Little North Santiam River, such as high turbidity, affect treatment and delivery of the drinking water. Between 2001 and 2008, suspended-sediment loads from the Little North Santiam River accounted for 69% of the total suspended-sediment load that passed the treatment plant. Recent studies suggest that much of this sediment originates from landslide activity in the basin. Using airborne Light Detection and Ranging (LiDAR)-derived imagery, 401 landslides were mapped in the Little North Santiam River Basin. Landslide types vary by location, with deep-seated earth flows and earth slumps common in the lower half of the basin and channelized debris flows prominent in the upper basin. Over 37% of the lower basin shows evidence of landslide activity compared to just 4% of the upper basin. Instream turbidity monitoring and suspended-sediment load estimates during the winter of 2009-2010 demonstrate a similar distribution of sediment transport in the basin. During a 3-month study period, from December 2009 through February 2010, the lower basin supplied 2,990 tons, or 91% of the suspended-sediment load to the Little North Santiam River, whereas the upper basin supplied only 310 tons of sediment. One small 23-acre earth flow in the lower basin, the Evans Creek Landslide, supplied 28% of the total suspended-sediment load, even though it only comprises 0.0004% of the basin. The Evans Creek Landslide is an active earth flow that has been moving episodically since at least 1945, with surges occurring between 1945 and 1955, 1970 and 1977, in February 1996, and in January 2004. Recent erosion of the landslide toe by Evans Creek continues to destabilize the slope, supplying much of the sediment measured in the Little North Santiam River. Over the last 64 years, the average landslide movement rate has been between 5 and 12 feet per year
Water-Quality Conditions and Suspended-Sediment Transport in the Wilson and Trask Rivers, Northwestern Oregon, Water Years 2012-14 by Steven Sobieszczyk( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

In October 2011, the U.S. Geological Survey began investigating and monitoring water-quality conditions and suspended-sediment transport in the Wilson and Trask Rivers, northwestern Oregon. Water temperature, specific conductance, turbidity, and dissolved oxygen were measured every 15-30 minutes in both streams using real-time instream water-quality monitors. In conjunction with the monitoring effort, suspended-sediment samples were collected and analyzed to model the amount of suspended sediment being transported by each river. Over the course of the 3-year study, which ended in September 2014, nearly 600,000 tons (t) of suspended-sediment material entered Tillamook Bay from these two tributaries. Each year of the study, the Wilson River transported between 80,300 and 240,000 t of suspended sediment, while the Trask River contributed between 28,200 and 69,900 t. The suspended-sediment loads observed during the study were relatively small because streamflow conditions were routinely lower than normal between October 2011 and September 2014. Only one storm had a recurrence interval between a 2- and 5-year event. Every other storm produced streamflows equivalent to what would be classified as a 1- or 2-year event. Because most sediment moves during high flows, the lack of heavy rainfall and elevated streamflows muted any high sediment loads. Along with assessing suspended-sediment transport, the U.S. Geological Survey also monitored instream water quality. This monitoring was used to track instream conditions and relate them to water temperature, dissolved oxygen, and sedimentation issues for the Wilson and Trask Rivers. Stream temperatures in the Wilson and Trask Rivers exceeded the temperature standard for cold-water habitat. Water temperatures at both streams exceeded the standard for more than 30 percent of the year, as stream temperatures increased above the seasonal 13 degrees Celsius (°C) (seasonal core cold-water habitat) and 16 °C (salmon and steelhead [Oncorhynchus mykiss] spawning) thresholds. Conversely, dissolved oxygen concentrations rarely decreased to less than the absolute water-quality criterion of 8 milligrams per liter for cold-water streams. Results from this study will provide resource managers insight into the seasonality of water-quality conditions and the extent of suspended-sediment transport in the Wilson and Trask Rivers. The data are useful for establishing a baseline and for maintaining best-use land management practices and possibly for aiding in prioritization of restoration actions for both rivers and their respective watersheds
Audience Level
Audience Level
  Kids General Special  
Audience level: 0.44 (from 0.43 for Analysis o ... to 0.81 for Major turb ...)