|
New Releases by H. JohnsonH. Johnson is the author of Johnny Was His Name (2023), A Transformed Life (2023), Listening in Paris (2023), Developmental Cognitive Neuroscience (2023), The Three Lights (2022).
release date: Dec 19, 2023
release date: Dec 06, 2023
release date: Apr 28, 2023
Developmental Cognitive Neuroscience
release date: Mar 28, 2023
release date: Dec 14, 2022
release date: Oct 26, 2022
release date: Sep 15, 2022
Phrases and Names, Their Origins and Meanings
release date: Sep 04, 2022
release date: Oct 11, 2021
Historical Dictionary of Afghanistan
release date: May 15, 2021
School-Based Behavioral Assessment, Second Edition
release date: Jan 08, 2021
release date: Dec 01, 2019
release date: Mar 19, 2018
release date: Feb 05, 2018
release date: Feb 01, 2018
release date: Jan 10, 2017
release date: Nov 15, 2016
release date: Oct 14, 2016
release date: May 31, 2016
release date: Nov 16, 2015
Investigation Into The Reliefs Of Generals Orlando Ward And Terry Allen
release date: Nov 06, 2015
release date: Jul 08, 2015
The Rise of Informal Logic
release date: Jul 15, 2014
Philosophy: a Path with Heart
release date: Apr 02, 2014
release date: Feb 03, 2014
Fundamentals of Argumentation Theory
release date: Nov 05, 2013
Natural Gas Hydrate - Arctic Ocean Deepwater Resource Potential
release date: Oct 11, 2013
Geomorphic analysis of the river response to sedimentation downstream of Mount Rainier, Washington
release date: Dec 07, 2012
A study of the geomorphology of rivers draining Mount Rainier, Washington, was completed to identify sources of sediment to the river network; to identify important processes in the sediment delivery system; to assess current sediment loads in rivers draining Mount Rainier; to evaluate if there were trends in streamflow or sediment load since the early 20th century; and to assess how rates of sedimentation might continue into the future using published climate-change scenarios. Rivers draining Mount Rainier carry heavy sediment loads sourced primarily from the volcano that cause acute aggradation in deposition reaches as far away as the Puget Lowland. Calculated yields ranged from 2,000 tonnes per square kilometer per year [(tonnes/km2)/yr] on the upper Nisqually River to 350 (tonnes/km2)/yr on the lower Puyallup River, notably larger than sediment yields of 50–200 (tonnes/km2)/yr typical for other Cascade Range rivers. These rivers can be assumed to be in a general state of sediment surplus. As a result, future aggradation rates will be largely influenced by the underlying hydrology carrying sediment downstream. The active-channel width of rivers directly draining Mount Rainier in 2009, used as a proxy for sediment released from Mount Rainier, changed little between 1965 and 1994 reflecting a climatic period that was relatively quiet hydrogeomorphically. From 1994 to 2009, a marked increase in geomorphic disturbance caused the active channels in many river reaches to widen. Comparing active-channel widths of glacier-draining rivers in 2009 to the distance of glacier retreat between 1913 and 1994 showed no correlation, suggesting that geomorphic disturbance in river reaches directly downstream of glaciers is not strongly governed by the degree of glacial retreat. In contrast, there was a correlation between active-channel width and the percentage of superglacier debris mantling the glacier, as measured in 1971. A conceptual model of sediment delivery processes from the mountain indicates that rockfalls, glaciers, debris flows, and main-stem flooding act sequentially to deliver sediment from Mount Rainier to river reaches in the Puget Lowland over decadal time scales. Greater-than-normal runoff was associated with cool phases of the Pacific Decadal Oscillation. Streamflow-gaging station data from four unregulated rivers directly draining Mount Rainier indicated no statistically significant trends of increasing peak flows over the course of the 20th century. The total sediment load of the upper Nisqually River from 1945 to 2011 was determined to be 1,200,000±180,000 tonnes/yr. The suspended-sediment load in the lower Puyallup River at Puyallup, Washington, was 860,000±300,000 tonnes/yr between 1978 and 1994, but the long-term load for the Puyallup River likely is about 1,000,000±400,000 tonnes/yr. Using a coarse-resolution bedload transport relation, the long-term average bedload was estimated to be about 30,000 tonnes/yr in the lower White River near Auburn, Washington, which was four times greater than bedload in the Puyallup River and an order of magnitude greater than bedload in the Carbon River. Analyses indicate a general increase in the sediment loads in Mount Rainier rivers in the 1990s and 2000s relative to the time period from the 1960s to 1980s. Data are insufficient, however, to determine definitively if post-1990 increases in sediment production and transport from Mount Rainier represent a statistically significant increase relative to sediment-load values typical from Mount Rainier during the entire 20th century. One-dimensional river-hydraulic and sediment-transport models simulated the entrainment, transport, attrition, and deposition of bed material. Simulations showed that bed-material loads were largest for the Nisqually River and smallest for the Carbon River. The models were used to simulate how increases in sediment supply to rivers transport through the river systems and affect lowland reaches. For each simulation, the input sediment pulse evolved through a combination of translation, dispersion, and attrition as it moved downstream. The characteristic transport times for the median sediment-size pulse to arrive downstream for the Nisqually, Carbon, Puyallup, and White Rivers were approximately 70, 300, 80, and 60 years, respectively.
release date: Nov 12, 2012
Crafting Short Screenplays That Connect
release date: Sep 10, 2012
|
|