Suspended Sediment and Turbidity Restrictions Associated With Instream Construction Activities in the United States: An Assessment of Biological Relevance

1998 ◽  
Author(s):  
Scott M. Reid ◽  
Paul G. Anderson
Keyword(s):  
United States ◽  
Sediment Transport ◽  
Suspended Sediment ◽  
Primary Productivity ◽  
The United States ◽  
Sediment Deposition ◽  
Timing Constraints ◽  
Aquatic Resources ◽  
Biological Relevance ◽  
Construction Methods

Sediment released during pipeline water crossings has the potential to negatively affect downstream aquatic resources. Regulation of pipeline water crossings has been directed through the application of allowable construction methods, timing constraints and numerical turbidity restrictions on construction permits. Past applications of turbidity restrictions are criticized for the following reasons: duration of exposure or sediment deposition effects are not considered; some applied restrictions are for the protection of primary productivity in lakes; and, defined mixing zones do not appear to incorporate expected levels of sediment generation, or sediment transport principles. Alternate approaches to defining permit restriction are proposed.

scholarly journals A new large-scale suspended sediment model and its application over the United States

2021 ◽  
Author(s):  
Hong-Yi Li ◽  
Zeli Tan ◽  
Hongbo Ma ◽  
Zhenduo Zhu ◽  
Guta Abeshu ◽  
...  
Keyword(s):  
United States ◽  
Sediment Transport ◽  
Suspended Sediment ◽  
The United States ◽  
Transport Processes ◽  
Model Parameters ◽  
Earth System ◽  
Sediment Discharge ◽  
River Systems ◽  
Monthly Streamflow

Abstract. Suspended sediment plays a vital role in the regional and global cycling of carbon and nutrients by carrying carbon and nutrients from headwaters into lowland rivers and the oceans. Sediment transport through river systems is often fundamentally modified by human activities like reservoir management. However, a physically based representation of sediment transport is still missing in most existing earth system models (ESMs), which are essential tools for modeling and predicting earth system changes. Here, we introduce a multi-process river sediment module for ESMs, which includes: 1) hillslope soil erosion and sediment discharge into streams; 2) sediment transport processes through river networks; 3) reservoir operation based on the inflows from upstream areas and water demand from downstream areas; and 4) sediment trapping by reservoirs. All model parameters are estimated a priori without calibration. We apply this new sediment modeling framework to the contiguous United States and validate it against historical observations of monthly streamflow and sediment discharges at 35 river gauges. The model reasonably well captures the long-term balance and seasonal variations of suspended sediment in large river systems. Furthermore, our model results show that suspended sediment discharge in managed rivers is affected more by reservoirs' direct trapping of sediment particles than by their flow regulation. This new sediment module enables future modeling of the transportation and transformation of carbon and nutrients carried by the fine sediment along the river-ocean continuum to close the global carbon and nutrients cycles.

scholarly journals Part of the Solution

2010 ◽  
Vol 132 (01) ◽  
pp. 46-49 ◽  
Author(s):  
Jean Thilmany
Keyword(s):  
United States ◽  
Rapid Prototyping ◽  
Affordable Housing ◽  
Low Cost ◽  
The United States ◽  
Industrialized Countries ◽  
Construction Methods ◽  
Emergency Housing ◽  
Low Cost Housing ◽  
New Buildings

This article presents numerous examples of rapid prototyping applications in the United States and explains its benefits. Constructing housing via rapid prototyping methods is expected to save time and money and bring affordable and environmentally friendly housing to people in need. Using an additive-manufacturing technique for constructing new buildings could provide emergency housing for victims of disasters. The technique could also be used for affordable housing for those in the United States or in third-world countries, or for creating new housing styles that bring curved, organic designs rather than straight surfaces to the homes. In industrialized countries, automating the manufacturing of products such as shoes or cars can cut costs about 25% as compared to manual construction methods. Makers of rapid prototyping technology are using CT scans to create exact-fit implants for craniofacial and maxillofacial operations. The rapid prototyping process is also being matched with humanitarian efforts in another project, this one situated in war-torn Iraq. Analysts suggest that custom medical devices and low-cost housing—affordable for everyone and quick to manufacture accurately—will help grow rapid prototyping into a robust industry.

scholarly journals Large-scale suspended sediment transport and sediment deposition in the Mekong Delta

2014 ◽  
Vol 18 (8) ◽  
pp. 3033-3053 ◽  
Author(s):  
N. V. Manh ◽  
N. V. Dung ◽  
N. N. Hung ◽  
B. Merz ◽  
H. Apel
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Large Scale ◽  
Transport Model ◽  
Mekong Delta ◽  
Sediment Dynamics ◽  
Sediment Deposition ◽  
Mineral Fertilizers ◽  
Suspended Sediment Transport ◽  
Extreme Flood

Abstract. Sediment dynamics play a major role in the agricultural and fishery productivity of the Mekong Delta. However, the understanding of sediment dynamics in the delta, one of the most complex river deltas in the world, is very limited. This is a consequence of its large extent, the intricate system of rivers, channels and floodplains, and the scarcity of observations. This study quantifies, for the first time, the suspended sediment transport and sediment deposition in the whole Mekong Delta. To this end, a quasi-2D hydrodynamic model is combined with a cohesive sediment transport model. The combined model is calibrated using six objective functions to represent the different aspects of the hydraulic and sediment transport components. The model is calibrated for the extreme flood season in 2011 and shows good performance for 2 validation years with very different flood characteristics. It is shown how sediment transport and sediment deposition is differentiated from Kratie at the entrance of the delta on its way to the coast. The main factors influencing the spatial sediment dynamics are the river and channel system, dike rings, sluice gate operations, the magnitude of the floods, and tidal influences. The superposition of these factors leads to high spatial variability of sediment transport, in particular in the Vietnamese floodplains. Depending on the flood magnitude, annual sediment loads reaching the coast vary from 48 to 60% of the sediment load at Kratie. Deposited sediment varies from 19 to 23% of the annual load at Kratie in Cambodian floodplains, and from 1 to 6% in the compartmented and diked floodplains in Vietnam. Annual deposited nutrients (N, P, K), which are associated with the sediment deposition, provide on average more than 50% of mineral fertilizers typically applied for rice crops in non-flooded ring dike floodplains in Vietnam. Through the quantification of sediment and related nutrient input, the presented study provides a quantitative basis for estimating the benefits of annual Mekong floods for agriculture and fishery, and is an important piece of information with regard to the assessment of the impacts of deltaic subsidence and climate-change-related sea level rise on delta morphology.

Sediment Production in a small Appalachian Watershed during Spring Runoff: The Eaton Basin, 1970–1972

1973 ◽  
Vol 10 (12) ◽  
pp. 1707-1734 ◽  
Author(s):  
M. A. Carson ◽  
C. H. Taylor ◽  
B. J. Grey
Keyword(s):  
United States ◽  
Sediment Transport ◽  
The United States ◽  
Channel Network ◽  
Discharge Data ◽  
Sediment Rating Curve ◽  
Sediment Yields ◽  
Sediment Production ◽  
Spring Runoff

This report describes work in an IHD Representative Basin in the Quebec Appalachians, the Eaton River Basin (86 km2 in area), upstream from Randboro. The Basin is dominantly forest-covered, contains no large settlement, and, in general, shows little human disturbance that might affect sediment production. The suspended load of the Eaton River was studied in detail during the spring runoff periods of 1970 and 1971; available long-term discharge data indicate these to be representative of present-day conditions. Sediment transport rates are well below capacity and sediment yields are lower than might have been expected from the Langbein-Schumm data in the United States. Suspended sediment originates primarily from scour of the banks of the channel network, and concentrations show a systematic increase with basin area (or distance downstream), quite unlike previous data from the midwestern United States. The sediment rating curve approach is a very good predictor of sediment transport rates, although because of the differences in hydrograph type, there is a large difference between the equations for the 1970 and 1971 spring floods. This difference, and residuals from the sediment rating curves, are considered in a simulation model of sediment production from bank erosion based on the changing shear resistance of bank sediment during a fluctuating hydrograph.

Tanning and Tanneries: An Introduction to Archaeology of the Leather Industry

1997 ◽  
Vol 18 (2) ◽  
pp. 121-147
Author(s):  
William B. Grobbel
Keyword(s):  
United States ◽  
The United States ◽  
Early History ◽  
Alexander Hamilton ◽  
Medieval Period ◽  
Leather Industry ◽  
Construction Methods ◽  
History Of ◽  
Materials Used ◽  
Tanning Industry

In his 1791 report on the state of manufactures and industries in the United States, Alexander Hamilton observed that there were “scarcely any manufactures of greater importance” (Welsh, 1964:13) than the leather tanning industry. The introduction and early history of this industry in North America was largely influenced by Old World traditions that developed during the medieval period. These traditions included methods of tanning, construction methods, and materials used to build tanneries, and even the places tanners chose to build their tanneries. Before these traditions can be explored, though, there needs to be an understanding of what tanning is, and how it is accomplished.

scholarly journals A Research Framework to Integrate Cross-Ecosystem Responses to Tropical Cyclones

BioScience ◽  
2020 ◽  
Vol 70 (6) ◽  
pp. 477-489 ◽  
Author(s):  
J Aaron Hogan ◽  
Rusty A Feagin ◽  
Gregory Starr ◽  
Michael Ross ◽  
Teng-Chiu Lin ◽  
...  
Keyword(s):  
United States ◽  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
Primary Productivity ◽  
Recovery Time ◽  
The United States ◽  
Ecosystem Response ◽  
Ecosystem Responses ◽  
Research Framework ◽  
Antecedent Conditions

Abstract Tropical cyclones play an increasingly important role in shaping ecosystems. Understanding and generalizing their responses is challenging because of meteorological variability among storms and its interaction with ecosystems. We present a research framework designed to compare tropical cyclone effects within and across ecosystems that: a) uses a disaggregating approach that measures the responses of individual ecosystem components, b) links the response of ecosystem components at fine temporal scales to meteorology and antecedent conditions, and c) examines responses of ecosystem using a resistance–resilience perspective by quantifying the magnitude of change and recovery time. We demonstrate the utility of the framework using three examples of ecosystem response: gross primary productivity, stream biogeochemical export, and organismal abundances. Finally, we present the case for a network of sentinel sites with consistent monitoring to measure and compare ecosystem responses to cyclones across the United States, which could help improve coastal ecosystem resilience.

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