Water Level Regulations and Fisheries in Rainy Lake and the Namakan Reservoir

1993 ◽  
Vol 50 (9) ◽  
pp. 1934-1945 ◽  
Author(s):  
Yosef Cohen ◽  
Paul Radomski
Keyword(s):  
Water Level ◽  
Interspecific Interactions ◽  
Water Levels ◽  
Fish Populations ◽  
Coregonus Clupeaformis ◽  
Spawning Habitat ◽  
Emergent Macrophytes ◽  
Dry Spells ◽  
The Difference ◽  
Yearly Maximum

The difference between the yearly maximum and minimum water levels (YMXR) is an index of lake dynamics: shoals are exposed and inundated, nutrients are oxidized and reduced, and the diversity and density of the aquatic plant community are affected. Shoals and emergent macrophytes provide spawning habitat for fish. The 5-yr moving variance of YMXR fluctuates regularly with periods of about 11.2 yr (periodicity of sunspot cycles). This reflects the effects of within-year consecutive periods of storms and dry spells. Water level regulations resulted in changes in both amplitudes and frequencies of YMXR compared with natural fluctuations. We established links between fluctuations in YMXR and fluctuations in fish populations. Water level regulations, through their effects on YMXR, corresponded to changes in interspecific interactions on Rainy Lake and the Namakan Reservoir. In both, walleye's (Stizostedion vitreum) fluctuations were synchronized with both those of lake whitefish (Coregonus clupeaformis) and northern pike (Esox lucius) more than those of either species with the other two. On the Namakan Reservoir, YMXR fluctuations were accentuated by water level regulation; on Rainy Lake, they were dampened. Regulations should consider frequencies and amplitudes of changes in water level and their effect on fish populations.

Low-cost river discharge measurements using a transparent velocity-head rod

2020 ◽  
Author(s):  
Aurélien Despax ◽  
Jérôme Le Coz ◽  
Francis Pernot ◽  
Alexis Buffet ◽  
Céline Berni
Keyword(s):  
Water Level ◽  
Low Cost ◽  
Electrical Contact ◽  
Field Tests ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Velocity Head ◽  
Low Velocity ◽  
Average Deviation ◽  
The Difference

<p>The common streamgauging methods (ADCP, current-meter or tracer dilution) generally require expensive equipment, with the notable exception of volumetric gaugings and floats, which are however often difficult to implement and limited to specific conditions. The following work aims at testing and validating a reliable, easy-to-deploy and low-cost gauging method, at a cost typically below 40 € each.<br><br>The “velocity-head rod” firstly described by Wilm and Storey (1944), made transparent by Fonstad et al. (2005) and improved by Pike et al. (2016) meets these objectives, for wading gauging with velocities greater than 20 cm/s typically. The 9.85 cm wide clear plastic rod is placed vertically across the stream to identify upstream and downstream water levels using adjustable rulers. The difference in level (or velocity head) makes it possible to calculate the average velocity over the vertical, using a semi-empirical calibration relationship.<br><br>Experiments carried out in INRAE’s hydraulic laboratory and in the field have enabled us to find a calibration relationship similar to that proposed by Pike et al. (2016) and confirm the optimal conditions of use. The average deviation to a reference discharge has been found to be close to 5 % except for very slow-flow conditions. The influence of the width of the rod on the velocity-head was studied in the laboratory. The uncertainty of the velocity due to the reading of water levels has been estimated. It increases at low velocity due to decreasing sensitivity, and increases at high velocities due to water level fluctuations that are difficult to average.<br><br>Several improvements were tested in order to facilitate and improve the measurement operations, without increasing the cost too much: magnetic ruler, removal of a graduated steel rule (expensive), plastic ruler with water level and velocity graduations, reading the depth with another ruler, spirit level, electrical contact (so the operator has not to bend to the surface of the water). An operational procedure and a spreadsheet for computing discharge are proposed. The method being extremely simple and quick to apply is well suited for rapid estimates of flow (instead of floats), training or demonstrations, citizen science programs or cooperation with services with limited resources.</p><p>Acknowledgments<strong>: </strong>The authors thank Q. Morice, J. Cousseau, Y. Longefay (DREAL) who were involved in this study by carrying out field tests.</p>

Influence of Water Level Drawdown on the Fish Populations of Cross Lake, Manitoba

1984 ◽  
Vol 41 (1) ◽  
pp. 118-125 ◽  
Author(s):  
M. N. Gaboury ◽  
J. W. Patalas
Keyword(s):  
Water Level ◽  
Hatching Success ◽  
Northern Pike ◽  
Water Levels ◽  
Coregonus Clupeaformis ◽  
Spawning Areas ◽  
Influence Of Water ◽  
Coregonus Artedii ◽  
Water Volumes ◽  
Coregonid Fishes

Regulated discharges into Cross Lake, Manitoba, resulted in average summer water volumes in 1980 and 1981 that were 49% lower than preregulated volumes. Water level drawdown in the summer reduces the amount of available habitat. Consequently, the standing crops of lake whitefish (Coregonus clupeaformis), walleye (Stizostedion vitreum vitreum), northern pike (Esox lucius), and Cisco (Coregonus artedii) are lower now than in preregulation and early postregulation years. Unusually early and rapid drawdown in March 1981 resulted in a severe winterkill, causing a substantial decrease in catches per unit of effort (CPUE) for most species from 1980 to 1981. The most affected species were whitefish and cisco, which showed a 50% reduction in CPUE from 1980 to 1981. The amount of fall to late spring drawdown and the year-class strengths of coregonid fishes were inversely related. A marked overwinter drawdown reduces whitefish and cisco hatching success apparently by dewatering their spawning areas and desiccating the eggs. Low water levels in spring prevented pike and walleye access to spawning areas.

scholarly journals The Functioning of Drainage Canal Near Barrage “Brzeg Dolny” on the Odra River in 1971–2009

2014 ◽  
Vol 22 (1) ◽  
pp. 61-66
Author(s):  
Beata Olszewska ◽  
Leszek Pływaczyk ◽  
Wojciech Łyczko
Keyword(s):  
Water Level ◽  
Water Flow ◽  
Cross Section ◽  
Water Levels ◽  
Drainage Canal ◽  
Water Conditions ◽  
Odra River ◽  
Flow Intensity ◽  
The Difference ◽  
Similar Location

Abstract The paper analyses the amount of water flowing into the drainage canal in comparison to the levels of the Odra waters in the Brzeg Dolny – Wały cross section (upper water in the barrage). The results of the measurement of the flow intensity in the canal in 1971–2009 provided the basis for the evaluation. The analysis led to the conclusion that with the same ordinate of damming in the barrage the average yearly flow in the canal in the Warzyna section decreased from 196 m3s–1 to about 80 dm3s–1 as the Odra's riverbed and the area between the embankments became tighter. The flow into the canal changes in time and depends on the difference between water levels in the Odra and in the canal. The paper presents the dynamics of changes in the water flow into the canal in relation to 1 m of difference between the level of water in the Odra and the drainage canal. It was shown that in a similar location, ground and water conditions as well as similar damming levels, the value of the drained water can be estimated to be about 35–40 dm3s–1km–1 for 1 meter of difference of the water level in the river and the canal.

CrowdWater: How well can citizens observe water levels and other hydrological variables using a smartphone app?

2021 ◽  
Author(s):  
Jan Seibert ◽  
Simon Etter ◽  
Barbara Strobl ◽  
Sara Blanco ◽  
Mirjam Scheller ◽  
...  
Keyword(s):  
Water Level ◽  
Citizen Science ◽  
General Information ◽  
Water Levels ◽  
Smartphone App ◽  
Monitoring Networks ◽  
Plastic Pollution ◽  
Temporary Streams ◽  
The Difference ◽  
Set Up

<p>Citizen science observations are potentially useful to complement existing monitoring networks. This is also the case in hydrology, where we often lack spatially distributed observations. Engaging the public might help to overcome the lack of data in hydrology. So far, most hydrological citizen science projects have been based on the use of different instruments or installations. For stream level observations, a staff gauge is installed in the river but it is difficult to scale this type of citizen science approach to a large number of sites because these gauges cannot be installed everywhere (or by everyone). Here, we present an evaluation of the CrowdWater smartphone app that allows the collection of hydrological data without any physical installation or specialized instruments. With the help of a free app, citizens can report the stream level, soil moisture conditions, the presence of water in temporary streams, plastic pollution in streams and on streambanks, as well as general information on streams. The approach is similar to geocaching, with the difference that instead of finding treasures, hydrological measurement sites are set up. These sites can be found by the initiator or other citizen scientists to take additional measurements at a later time. For the water level measurements, a virtual staff gauge approach is used instead of a physical staff gauge. A picture of a staff gauge is digitally inserted into a photo of a stream bank or a bridge pillar and serves as a reference of the water level. During a subsequent field visit, the stream level is compared to the virtual staff gauge on the first picture. In this presentation, we discuss how well the water level class observations agreed with measured stream levels, and in which months and during which flow conditions citizens submitted their stream level observations. We also highlight methods to ensure data quality, and illustrate how these water level data can be used in hydrological model calibration. We also give an update on new activities in the CrowdWater project.</p>

scholarly journals Monitoring of Water Level Change in a Dam from High-Resolution SAR Data

2021 ◽  
Vol 13 (18) ◽  
pp. 3641
Author(s):  
Yoon-Kyung Lee ◽  
Sang-Hoon Hong ◽  
Sang-Wan Kim
Keyword(s):  
High Resolution ◽  
Water Level ◽  
Water Levels ◽  
Sar Interferometry ◽  
Upstream Face ◽  
Surface Model ◽  
Face Modeling ◽  
Small Satellites ◽  
Lakes And Reservoirs ◽  
The Difference

Accurate measurement of water levels and variations in lakes and reservoirs is crucial for water management. The retrieval of the accurate variations in water levels in lakes and reservoirs with small widths from high-resolution synthetic aperture radar (SAR) images such as the TerraSAR add-on for Digital Elevation Measurements (TanDEM-X) and COnstellation of small Satellites for the Mediterranean basin Observation (COSMO-SkyMed) are presented here. A detailed digital surface model (DSM) for the upstream face of the dam was constructed using SAR interferometry with TanDEM-X data to estimate the water level. The elevation of the waterline below that of the interferometric SAR (InSAR) DSM was estimated based on upstream face modeling. The waterline boundary detected using the SAR Edge Detection Hough Transform algorithm was applied to the restored DSM. The SAR-derived water level variations showed a high correlation coefficient of 0.99 and a gradient of 1.08 with the gauged data. The difference between the gauged data and SAR-derived data was within ±1 m, and the standard deviation of the residual was 0.60 m. These results suggest that water level estimation can be used as an operational supplement for traditional gauged data at remote sites.

scholarly journals Dynamics and consequences of water level fluctuations of selected lakes in the catchment of the Ostrowo-Gopło Channel

2014 ◽  
Vol 14 (4) ◽  
pp. 187-194 ◽  
Author(s):  
Adam Piasecki ◽  
Włodzimierz Marszelewski
Keyword(s):  
Water Level ◽  
Field Studies ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Dynamic Changes ◽  
Type Change ◽  
The Mean ◽  
The Difference ◽  
High Precipitation ◽  
Lake Type

Abstract The article discusses water level fluctuations in lakes and the associated changes in the lake surface and water resources in the years 1992-2011. On the basis of detailed field studies carried out in the hydrological year 2011, short-term and dynamic changes in the lakes’ hydrology were determined. Changes in hydrological lake types were evoked by unexpected hydro-meteorological situations, in particular high precipitation totals and sudden thaws in winter. The main symptom of the lake type change was the restoration, after nearly 10 years, of channels connecting the lakes. In addition, a strong interdependence was recorded in the difference between evaporation and precipitation, as well as the mean annual ranges of lake water levels in the years 1992-2010

scholarly journals Droughts, Dry Spells and Low Water Levels in Late Medieval Hungary (and Slavonia) III: Potential Dry Spells and the Drought of (1516-)1517

2019 ◽  
Vol 12 (3-4) ◽  
pp. 53-67 ◽  
Author(s):  
Andrea Kiss
Keyword(s):  
Water Level ◽  
Tree Ring ◽  
Large Scale ◽  
Water Levels ◽  
Local Data ◽  
Late Medieval ◽  
Dry Spells ◽  
Danube Catchment ◽  
Problems And Solutions ◽  
Regional Problems

Abstract As a continuation of the series about droughts in late medieval Hungary, we present, analyse and compare further cases, based on contemporary direct and indirect documentary source evidence. The data, concerning (potential) low water-level conditions in 1375, 1378, 1393-1394 and 1517, and the economic problems (and solutions) probably related to multiannual dry (spring, summer?) conditions, recorded in the 1410s and 1420s, are further compared to the recent tree-ring based hydroclimate reconstruction of the OWDA (Old World Drought Atlas). Whereas the cases in 1371, 1375, 1378, (1414-)1417 and 1427-1428 (and before) reflect on local-regional problems and also show some conflicts between documentary and tree-ring based reconstructions, in 1393 the local data and the potential Danube low water-level evidence mainly reflects on lower precipitation sums in Western Hungary and the Upper-Danube catchment. The 1517 case, however, presumably refers to large-scale drought problems in the Carpathian Basin and beyond. Beyond the case studies on individual years or multiannual periods, indirect indicators of drought and dry spells are discussed and main groups of most frequent (potential) indicators defined. Preceded by a hard winter, the year of Reformation stands out both in documentary and tree-ring evidence as an outstanding drought year, and has particular importance in the paper.

AUTOMATIC WATER LEVEL MONITORING WITH IOT AND LPWAN

2019 ◽  
pp. 95-103
Author(s):  
Krum Videnov ◽  
Vanya Stoykova
Keyword(s):  
Water Level ◽  
Real Time ◽  
Early Warning ◽  
Water Sources ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Level Monitoring ◽  
Water Level Monitoring

Monitoring water levels of lakes, streams, rivers and other water basins is of essential importance and is a popular measurement for a number of different industries and organisations. Remote water level monitoring helps to provide an early warning feature by sending advance alerts when the water level is increased (reaches a certain threshold). The purpose of this report is to present an affordable solution for measuring water levels in water sources using IoT and LPWAN. The assembled system enables recording of water level fluctuations in real time and storing the collected data on a remote database through LoRaWAN for further processing and analysis.

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