Effects of residence time on summer nitrate uptake in mississippi river flow-regulated backwaters

2008 ◽  
Vol 24 (9) ◽  
pp. 1206-1217 ◽  
Author(s):  
William F. James ◽  
William B. Richardson ◽  
David M. Soballe
Keyword(s):  
Residence Time ◽  
Mississippi River ◽  
Nitrate Uptake ◽  
River Flow

Residence Time in Hyporheic Bioactive Layers Explains Nitrate Uptake in Streams

2020 ◽  
Author(s):  
Angang Li ◽  
Susana Bernal ◽  
Brady Kohler ◽  
Steven A. Thomas ◽  
Eugènia Martí ◽  
...  
Keyword(s):  
Residence Time ◽  
Nitrate Uptake

Survival of fish passing downstream at a small hydropower facility

2018 ◽  
Vol 69 (12) ◽  
pp. 1870 ◽  
Author(s):  
Stephen V. Amaral ◽  
Benjamin S. Coleman ◽  
Jenna L. Rackovan ◽  
Kelly Withers ◽  
Benjamin Mater
Keyword(s):  
Mississippi River ◽  
River Flow ◽  
Survival Rates ◽  
Fish Populations ◽  
Negative Effects ◽  
Small Hydropower ◽  
The Usa ◽  
Pass Through ◽  
Hydro Project ◽  
Total Project

Hydropower dams can negatively affect upstream and downstream migratory fish populations in many ways, such as blocking access to upstream habitats and causing injuries or mortality during downstream passage. For downstream passage at projects in the USA, federal regulators and agencies responsible for oversight of hydropower facilities typically require assessment studies and mitigation to address negative effects, with a primary goal of minimising fish impingement and turbine entrainment and mortality. So as to assess the effects of downstream passage of fish populations at a unique, small hydro project on the Mississippi River, impingement and entrainment rates, Oberymeyer gate passage, spillway gate passage, turbine survival, and total downstream passage survival were estimated. It was determined that 85% of fish passing downstream at the project would be small enough to pass through the bar spacing of the trash racks and 15% would be physically excluded. When 55% of river flow enters the turbine intake channel, the total project survival rates were estimated to be 77.3% with an Obermeyer gate bypass rate of 10 and 96.6% with a gate bypass rate of 90%. Therefore, any effects on local fish populations resulting from the operation of the project are expected to be negligible and inconsequential on the basis of expected survival rates for the range and probability of river flows occurring at the project.

scholarly journals Uncertainty analysis of monthly river flow modeling in consecutive hydrometric stations using integrated data-driven models

2021 ◽  
Author(s):  
Karim Amininia ◽  
Seyed Mahdi Saghebian
Keyword(s):  
Data Processing ◽  
Uncertainty Analysis ◽  
Mississippi River ◽  
River Flow ◽  
Ensemble Empirical Mode Decomposition ◽  
Multivariate Adaptive Regression Splines ◽  
Applied Model ◽  
Flood Warning ◽  
Mode Decomposition ◽  
Artificial Intelligence Models

Abstract The flow assessment in a river is of vital interest in hydraulic engineering for flood warning and evacuation measures. To operate water structures more efficiently, models that forecast river discharge are desired to be of high precision and certain degree of accuracy. Therefore, in this study, two artificial intelligence models, namely kernel extreme learning machine (KELM) and multivariate adaptive regression splines (MARS), were applied for the monthly river flow (MRF) modeling. For this aim, Mississippi river with three consecutive hydrometric stations was selected as case study. Using the previous MRF values during the period of 1950–2019, several models were developed and tested under two scenarios (i.e. modeling based on station's own data or previous station's data). Wavelet transform (WT) and ensemble empirical mode decomposition (EEMD) as data processing approaches were used for enhancing modeling capability. Obtained results indicated that the integrated models resulted in more accurate outcomes. Data processing enhanced the model's capability up to 25%. It was observed that the previous station's data could be applied successfully for MRF modeling when the station's own data were not available. The best-applied model dependability was assessed via uncertainty analysis, and an allowable degree of uncertainty was found in MRF modeling.

Fishery Resources, Environment, and Conservation in the Mississippi and Yangtze (Changjiang) River Basins

2016 ◽  
Keyword(s):  
Mississippi River ◽  
River Restoration ◽  
River Flow ◽  
Mitigation Measures ◽  
Form And Function ◽  
Action Team ◽  
The World ◽  
Middle Mississippi River ◽  
Private Citizens ◽  
Sustainability Program

<em>Abstract</em>.—Ecosystem restoration of the Mississippi River main stem has been ongoing since the early 1970s. After the passage of environmental laws in the late 1960s to the early 1970s, private citizens and state and federal natural resource agency managers began to seek programs and funding for restoration and conservation that eventually resulted in mitigation measures of adverse impacts. Environmental-type actions that include the Great River Environmental Action Team, the Avoid and Minimize program, the middle Mississippi River biological opinion, and the lower Mississippi River conservation plan and biological opinion originated from laws or legal action. The Upper Mississippi River Restoration, Navigation and Ecosystem Sustainability Program, Restoring America’s Greatest River, and Operation and Maintenance activities, which support system ecological restoration measures, are, to a large extent, done in a cooperative setting to improve the river for multiple benefits. This coalition of agencies and professions has resulted in the application of hundreds of different types of measures to restore form and function to the third largest river in the world. Over the years, dredging and disposal practices have improved in an effort to minimize the impacts from these activities. Lost floodplain islands have been replaced, backwater lakes and channel depths have been recovered, active river flow has been reintroduced to backwaters, and microhabitats for special concern species have been restored, all to recreate broad functional floodplain habitat. Wing-dike and side-channel closure structures have been shortened, notched, or removed to recover flow along the main-channel border and side channels, increasing hydraulic residence time and recovering valuable habitat along with restoring nutrient and sediment assimilation processes the floodplain provides. Field monitoring has shown positive responses from endangered and threatened species, migratory and resident aquatic and wildlife species, abiotic conditions like water quality, and increased use by humans enjoying the benefit of a restored river system. Collectively, this work is some of the most extensive large river restoration in the world, but it only represents a small contribution to what is necessary to maintain a diverse and resilient Mississippi River. The information provided in this chapter provides a basis for continuing restoration efforts that should become a routine part of Mississippi River management.

Continental-Scale River Flow Modeling of the Mississippi River Basin Using High-Resolution NHDPlusDataset

2016 ◽  
Vol 53 (2) ◽  
pp. 258-279 ◽  
Author(s):  
Ahmad A. Tavakoly ◽  
Alan D. Snow ◽  
Cédric H. David ◽  
Michael L. Follum ◽  
David R. Maidment ◽  
...  
Keyword(s):  
High Resolution ◽  
River Basin ◽  
Mississippi River ◽  
River Flow ◽  
Mississippi River Basin ◽  
Flow Modeling ◽  
Continental Scale

Summer nitrate uptake and denitrification in an upper Mississippi River backwater lake: the role of rooted aquatic vegetation

2010 ◽  
Vol 104 (1-3) ◽  
pp. 309-324 ◽  
Author(s):  
Rebecca M. Kreiling ◽  
William B. Richardson ◽  
Jennifer C. Cavanaugh ◽  
Lynn A. Bartsch
Keyword(s):  
Mississippi River ◽  
Nitrate Uptake ◽  
Aquatic Vegetation ◽  
Upper Mississippi River

scholarly journals River Network Routing on the NHDPlus Dataset

2011 ◽  
Vol 12 (5) ◽  
pp. 913-934 ◽  
Author(s):  
Cédric H. David ◽  
David R. Maidment ◽  
Guo-Yue Niu ◽  
Zong-Liang Yang ◽  
Florence Habets ◽  
...  
Keyword(s):  
Information System ◽  
Mississippi River ◽  
Land Surface ◽  
River Flow ◽  
Land Surface Model ◽  
River Basins ◽  
Network Routing ◽  
River Network ◽  
Surface Model ◽  
Muskingum Method

Abstract The mapped rivers and streams of the contiguous United States are available in a geographic information system (GIS) dataset called National Hydrography Dataset Plus (NHDPlus). This hydrographic dataset has about 3 million river and water body reaches along with information on how they are connected into networks. The U.S. Geological Survey (USGS) National Water Information System (NWIS) provides streamflow observations at about 20 thousand gauges located on the NHDPlus river network. A river network model called Routing Application for Parallel Computation of Discharge (RAPID) is developed for the NHDPlus river network whose lateral inflow to the river network is calculated by a land surface model. A matrix-based version of the Muskingum method is developed herein, which RAPID uses to calculate flow and volume of water in all reaches of a river network with many thousands of reaches, including at ungauged locations. Gauges situated across river basins (not only at basin outlets) are used to automatically optimize the Muskingum parameters and to assess river flow computations, hence allowing the diagnosis of runoff computations provided by land surface models. RAPID is applied to the Guadalupe and San Antonio River basins in Texas, where flow wave celerities are estimated at multiple locations using 15-min data and can be reproduced reasonably with RAPID. This river model can be adapted for parallel computing and although the matrix method initially adds a large overhead, river flow results can be obtained faster than with the traditional Muskingum method when using a few processing cores, as demonstrated in a synthetic study using the upper Mississippi River basin.

scholarly journals DETERIORATION AND RESTORATION OF COASTAL WETLANDS

1970 ◽  
Vol 1 (12) ◽  
pp. 107 ◽  
Author(s):  
Sherwood M. Gagliano ◽  
Hyuck J. Kwon ◽  
Johannes L. Van Beek
Keyword(s):  
Mississippi River ◽  
Flood Control ◽  
River Flow ◽  
Management Plan ◽  
Sediment Deposition ◽  
Shelf Area ◽  
Land Loss ◽  
River Diversion ◽  
Building Process ◽  
Controlled Flow

Coastal Louisiana wetlands are a product of Mississippi River delta building that has occurred over a period of 5,000 years The building process was a gradual one, for riverine and marine processes were very nearly balanced In modern times man's use of the area (flood control, navigation improvement, exploitation of petroleum and other minerals, road building, etc ) has seriously altered the natural balance As a result, overbank flooding has been virtually eliminated and river flow is confined to channels discharging into the outer shelf area Most transported sediment is now deposited in the deep Gulf of Mexico or along the continental shelf Saltwater encroachment in the deltaic estuaries has been detrimental to fauna and flora Even though considerable sediment deposition has resulted from the historic Atchafalaya River diversion and growth of subdeltas, comparative map studies indicate a net land loss rate of 16 5 miles^/year during the last 25 to 30 years Land loss is only one symptom of general environmental deterioration A dynamic management plan is proposed for better utilization of combined freshwater discharge - dissolved solid and transported sediment input from the Mississippi River Controlled flow into estuaries will reduce salinity encroachment and supply badly needed nutrients Large areas of new marshland and estuarme habitat can be built by controlled subdelta diversion Studies of natural subdeltas indicate that these systems are amenable to environmental management, salinities and sediment deposition may be manipulated to enhance desired conditions.

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