The hydrologic regime of Mackenzie River and connection of "no-closure" lakes to distributary channels in the Mackenzie Delta, Northwest Territories

1995 ◽  
Vol 32 (7) ◽  
pp. 926-937 ◽  
Author(s):  
C. R. Burn
Keyword(s):  
Water Level ◽  
Drainage Basin ◽  
Late Summer ◽  
River System ◽  
Water Levels ◽  
Ice Thickness ◽  
Mackenzie Delta ◽  
Lake Ice ◽  
Discharge System ◽  
Mackenzie River

Mackenzie Delta lakes have been classified by the seasonal duration of their connection to Mackenzie River. "No-closure" lakes are determined on the basis of minimum summer water level. Such lakes may become disconnected from the Mackenzie in autumn or winter, as water level falls or if the sills between lakes and distributary channels are frozen through and so sealed. Water level in the central delta rises continuously after late November–early December, at first because discharge into the delta increases once the Mackenzie drainage basin has frozen over, and then as sea and channel ice thickens in the outer delta, impounding discharge. Since 1973 this seasonal increase in stage from its minimum in early December to the level on 1 April has been between 29 and 95 cm. Between 1987 and 1994, the rise in stage near Inuvik has been slightly greater than increases in lake-ice thickness (30–68 cm). Channels and lakes that are connected to the Mackenzie discharge system in December may remain connected throughout winter. A critical sill elevation for connection of such lakes to the river system is the minimum stage minus mid-December ice thickness. Recently, these elevations have been from 1.0 to 1.6 m lower than late summer water levels. Lakes with sill elevations still lower may remain connected to the Mackenzie throughout the year. In 1993-1994, only 3 of 16 "no-closure" lakes surveyed near Inuvik remained open to the Mackenzie discharge throughout winter, representing 2% of the lakes in this portion of the delta.

scholarly journals Feedback Mechanism in Bifurcating River Systems: the Effect on Water-Level Sensitivity

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1915
Author(s):  
Matthijs R.A. Gensen ◽  
Jord J. Warmink ◽  
Fredrik Huthoff ◽  
Suzanne J.M.H. Hulscher
Keyword(s):  
Water Level ◽  
Flood Risk ◽  
River System ◽  
Feedback Mechanism ◽  
Water Levels ◽  
River Systems ◽  
Water Level Variations ◽  
System Water ◽  
Discharge Distribution ◽  
Single Branch

Accurate and reliable estimates of water levels are essential to assess flood risk in river systems. In current practice, uncertainties involved and the sensitivity of water levels to these uncertainties are studied in single-branch rivers, while many rivers in deltas consist of multiple distributaries. In a bifurcating river, a feedback mechanism exists between the downstream water levels and the discharge distribution at the bifurcation. This paper aims to quantify the sensitivity of water levels to main channel roughness in a bifurcating river system. Water levels are modelled for various roughness scenarios under a wide range of discharge conditions using a one-dimensional hydraulic model. The results show that the feedback mechanism reduces the sensitivity of water levels to local changes of roughness in comparison to the single-branch river. However, in the smaller branches of the system, water-level variations induced by the changes in discharge distribution can exceed the water-level variations of the single-branch river. Therefore, water levels throughout the entire system are dominated by the conditions in the largest branch. As the feedback mechanism is important, the river system should be considered as one interconnected system in river maintenance of rivers, flood-risk analyses, and future planning of river engineering works.

Response in the trophic state of stratified lakes to changes in hydrology and water level: potential effects of climate change

2011 ◽  
Vol 2 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Dale M. Robertson ◽  
William J. Rose
Keyword(s):  
Water Level ◽  
Trophic State ◽  
Drainage Basin ◽  
High Water ◽  
Water Levels ◽  
Drainage Basins ◽  
Stratified Lakes ◽  
Seepage Lake ◽  
Groundwater Exchange ◽  
Induced Changes

To determine how climate-induced changes in hydrology and water level may affect the trophic state (productivity) of stratified lakes, two relatively pristine dimictic temperate lakes in Wisconsin, USA, were examined. Both are closed-basin lakes that experience changes in water level and degradation in water quality during periods of high water. One, a seepage lake with no inlets or outlets, has a small drainage basin and hydrology dominated by precipitation and groundwater exchange causing small changes in water and phosphorus (P) loading, which resulted in small changes in water level, P concentrations, and productivity. The other, a terminal lake with inlets but no outlets, has a large drainage basin and hydrology dominated by runoff causing large changes in water and P loading, which resulted in large changes in water level, P concentrations, and productivity. Eutrophication models accurately predicted the effects of changes in hydrology, P loading, and water level on their trophic state. If climate changes, larger changes in hydrology and water levels than previously observed could occur. If this causes increased water and P loading, stratified (dimictic and monomictic) lakes are expected to experience higher water levels and become more eutrophic, especially those with large developed drainage basins.

Stratigraphy of the Sixteen Mile Creek lagoon, and its implications for Lake Ontario water levels

1988 ◽  
Vol 25 (8) ◽  
pp. 1175-1183 ◽  
Author(s):  
J. E. Flint ◽  
R. W. Dalrymple ◽  
J. J. Flint
Keyword(s):  
Water Level ◽  
Lake Michigan ◽  
Drainage Basin ◽  
Average Rate ◽  
Lake Ontario ◽  
Open Water ◽  
Water Levels ◽  
Beach Sand ◽  
Water Level Fluctuations ◽  
Lake Outlet

The sequence of units (from the base up) in the Sixteen Mile Creek lagoon (Lake Ontario) mimics the longitudinal sequence of surficial environments: pink silt—overbank (flood plain – dry marsh); bottom sand—stream channel and beach; orange silt—marsh; gyttja—wet marsh and very shallow (deltaic) lagoon; and brown and grey clay—open-water lagoon. This entire sequence accumulated over the last 4200 years under slowly deepening, transgressive conditions caused by the isostatic rise of the lake outlet. Land clearing by European settlers dramatically increased the supply of clastic sediment and terminated the deposition of the organic-rich silty clays (gyttja) that make up most of the lagoon fill.Because the gyttja and beach sand are interpreted to have accumulated in water depths of less than 0.5 m, the elevation–time plot of 14C dates from these units can be used to reconstruct a very closely constrained lake-level curve. The data indicate that water levels have risen at an average rate of 0.25 cm/a over the last 3300 years as a result of differential, isostatic rebound. Superimposed on this trend are water-level oscillations with amplitudes on the order of 1 m and periods of several hundred years. These oscillations are synchronous and in phase with water-level fluctuations in Lake Michigan, and with a variety of other climatic variations in North America and Europe. We propose, therefore, that the water-level oscillations are a result of long-term, climatically produced variations in precipitation in the Great Lakes drainage basin.

scholarly journals CONTRIBUTION OF LARGE RIVER SYSTEM ON WATER LEVEL DUE TO A STORM

2018 ◽  
pp. 14
Author(s):  
Abdul Al Mohit ◽  
Yoshihiko Ide ◽  
Mitsuyoshi Kodama ◽  
Masaru Yamashiro ◽  
Noriaki Hashimoto
Keyword(s):  
Water Level ◽  
Water Discharge ◽  
Interaction Model ◽  
River System ◽  
Large River ◽  
Water Levels ◽  
Sea Surface ◽  
Surface Elevation ◽  
Small Rivers ◽  
Open Boundary

Bangladesh is a riverine country in South Asia, which contain about 700 big or small rivers. The major Ganges- Brahmaputra-Meghna river system makes the coast of Bangladesh more complex and disaster vulnerable area. This river system may or may not have its impact on the height of the water level due to a storm. This area is a suitable place for research, but there is no such mention of suitable research conducted in this area. Worth mentioning works done by some scholars are Dube et al. (2004), Agnihotri et al. (2006). All the works are important to the Bay-River interaction for the storm surge simulation, but these studies were also limited by the lack of a representation of proper geometry of the river system. Some of them considered idealized river system with constant water depth and some of them did not consider the proper tidal resume. The present study is a step towards the development of an operational surge forecasting nonlinear Bay-River interaction model that incorporates the major river system with realistic geometry. Both the bay and river model equations are discretized by finite difference method with central in space and forward in time and are solved by a conditionally stable, semi-implicit manner on a staggered Arakawa C-grid system. A stable tidal condition was made by forcing the sea level with the most energetic tidal constituent, M2 , along the southern open boundary of the parent model (Bay model). The developed model was applied to foresee sea-surface elevation associated with the catastrophic cyclone 1991 and a recent cyclone MORA 2017 along the coast of Bangladesh. We also investigated how the river influences the sea surface elevation with and without fresh water discharge. We also intend to investigate the effect of river discharge with sediment. It is observed that the water levels are found to be influenced by the river system.

scholarly journals Grey box modelling for river control

2002 ◽  
Vol 4 (4) ◽  
pp. 265-280 ◽  
Author(s):  
Björn Sohlberg ◽  
Mats Sernfält
Keyword(s):  
Water Level ◽  
Water Flow ◽  
Energy Demand ◽  
Power Plants ◽  
Energy Requirement ◽  
River System ◽  
Measured Data ◽  
Water Levels ◽  
Unknown Parameters ◽  
Power Stations

This paper deals with modelling and identification of a river system using physical insights about the process, experience of operating the system and information about the system dynamics shown by measured data. These components together form a linear model structure in the state space form. The inputs of the prospective model are physical variables, which are not directly measured. However, the model inputs can be found by a nonlinear transformation of measured variables. Unknown parameters of the model are estimated from measured data. The modelling work focuses on the principle of parsimony, which means the best model approach is the simplest one that fit the purpose of the application. The goal of the model is to control the water level of the river, where the water flow is mainly determined by the demand for energy generation produced by the hydropower stations along the river. The energy requirement increases in the morning and decreases in the evening. These flow variations, caused by the energy demand, have to be compensated by controlling the power plants downstream, in such a way that the water level between the power stations is guaranteed. Simulation of the control system by using an adaptive model predictive controller shows that the water levels vary less and can be maintained at a higher level than during manual control. This means that more electric power can be produced with the same amount of water flow.

scholarly journals Flood frequency analysis of the Djetinja river

2010 ◽  
Vol 90 (2) ◽  
pp. 15-28 ◽  
Author(s):  
Dragana Milijasevic
Keyword(s):  
Water Resources ◽  
Water Level ◽  
Frequency Analysis ◽  
Drainage Basin ◽  
Flood Frequency ◽  
Water Levels ◽  
Flood Frequency Analysis ◽  
Extreme Water Levels ◽  
High Flows ◽  
Hydrological Forecast

Based on extreme water levels data, using the method of series, a forecast for protection of river has been accomplished, i.e. probable water level maximums of the Djetinja river at Sengolj were measured. High flows were analyzed with a probability from 0.01% to 99.9%. These probabilities indicate the occurrence of high flows of certain values once in 10.000, 1.000, 100, 33, 20 etc years. Applying a hydrological forecast, one can perceive the possibility for using water resources for various purposes, as well as protection of areas and people from flooding. A review of the greatest floods in the Djetinja drainage basin in the last hundred years is given in this paper. .

Hydrodynamic modelling of compound flood drivers in estuaries

2020 ◽  
Author(s):  
Anais Couasnon ◽  
Dirk Eilander ◽  
Paul Bates ◽  
Hessel C. Winsemius ◽  
Philip J. Ward
Keyword(s):  
Time Series ◽  
Water Level ◽  
Transition Zone ◽  
River System ◽  
Water Levels ◽  
Flood Events ◽  
Sea Levels ◽  
Coastal Flood ◽  
Highly Nonlinear ◽  
Maximum Water

<p>Compound flooding in deltas and estuaries can be defined as the combination of various flood drivers leading to a significant flood impact (Zscheischler et al., 2018). For example, elevated sea-levels can impede flood drainage and create backwater effects that worsen flood damages. This was observed recently in March 2019 during cyclone Idai, where devastating floods from a high storm surge and discharge destroyed the port city of Beira. Even though the importance of accounting for compound flooding in flood risk assessments has been heavily underlined in recent literature, little research has been done on the impacts of compound flood events globally.</p><p>In this study, we investigate how compound flood hazard in estuaries is influenced by their various geophysical characteristics and the nature of their upstream river basins. The influence of riverine and coastal flood drivers on the water level varies along the estuary.  The water level at the river mouth is dependent on sea-levels, whereas one can expect this influence to reduce moving upstream in the river system and to become negligible completely upstream in large river systems. The location within a river system where both riverine and coastal flood drivers significantly contribute to the water level is referred to as the transition zone (Bilskie and Hagen, 2018).</p><p>We set up a model experiment to compare maximum water levels across realistic estuary types and boundary conditions. We use the 1-D unsteady hydrodynamic model LISFLOOD-FP to simulate water level time series for average and anomalous compound flood events of sea-levels and discharge. For each estuary type, resulting water level time series are analyzed to quantify the contribution of each flood driver in the maximum water level obtained along the complete coastal river profile and on the extent of the transition zone. We find that the interaction between the extreme sea level and extreme discharge is highly nonlinear and that this effect strongly varies depending on the estuary shape and length. We foresee this extensive overview of estuarine compound flood behavior to globally identify areas particularly vulnerable for interactions between extreme discharge and sea levels.</p>

scholarly journals Flood Pulse and Aquatic Habitat Dynamics of The Sentarum Floodplain Lakes Area

2021 ◽  
Vol 1 (1) ◽  
pp. 27-37
Author(s):  
Hidayat Hidayat ◽  
Siti Aisyah ◽  
Riky Kurniawan ◽  
Iwan Ridwansyah ◽  
Octavianto Samir ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Level ◽  
River System ◽  
Aquatic Habitat ◽  
Middle Part ◽  
Floodplain Lakes ◽  
Water Levels ◽  
Line Transect ◽  
Fish Diversity ◽  
Lake Area

The Lake Sentarum is a complex of floodplain lakes in the middle part of the Kapuas River system in West Kalimantan, Indonesia. The area has a great ecological and economic importance, however, the Sentarum lakes complex and its catchment area are generally threatened by deforestation, fire, monoculture agroindustry, and pollution.The objective of this research is to establish the hydrological characteristics of the Sentarum lakes area and to reveal the dynamics of aquatic habitat resulted from changing water levels. Data were collected during our field campaigns of 2013-2017 representing the seasons. The water level was measured using a pressure sensor placed at the Lake Sentarum National Park resort, while rainfall data were obtained from the data portal of the Tropical Rainfall Measuring Mission. Inundation monitoring was carried out using a time-lapse camera. A hydrological model is used to simulate water levels beyond measurement period. Water quality and fish sampling were carried out at the lake area. Vegetation observation was carried out at the selected riparian zone of the lake area using the line transect method. Water level records show that the Sentarum floodplain lakes have two peaks of inundation period following the bimodal pattern of rainfall in the equatorial Kapuas catchment. This water level dynamics induced changes in water quality, nutrient availability, vegetation cover, and fish diversity found in the Sentarum lakes area. Despite its seasonal changes, water quality of Sentarum lakes is generally good and suitable for aquatic biota. Fish diversity of the Sentarum lakes is relatively higher during high water periods.

Application of Water Temperatures to the Problem of Lateral Mixing in the Great Bear–Mackenzie River System

1972 ◽  
Vol 9 (7) ◽  
pp. 913-917 ◽  
Author(s):  
J. Ross Mackay
Keyword(s):  
River System ◽  
Temperature Profiles ◽  
Mackenzie Delta ◽  
River Temperature ◽  
Cross River ◽  
Lateral Mixing ◽  
Bear River ◽  
Better Than ◽  
Good Agreement ◽  
Mackenzie River

Cross-river temperature profiles were run in mid-June 1971 at approximately 20 km intervals from the confluence of the Great Bear and Mackenzie Rivers, at Fort Norman, N.W.T., to the Mackenzie Delta, a distance of 650 km. As the Great Bear River was cold, the Mackenzie River warm, and as temperatures were read to better than ±.01 °C in the field, the cross-profiles have provided a record of the lateral mixing of the two rivers. A flow distance of 500 km was required for nearly complete mixing. The 1971 cross-river temperature profiles and aerial infrared imagery taken in 1969 show a good agreement in the mixing pattern. It is suggested that where water temperature contrasts exist, temperatures, which can be read easily with a resolution of better than ±.01 °C, may serve as one of the easiest and most economical of the tracers suitable for mixing studies.

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