Test Methods for Measurement of Water Levels in Open-Water Bodies

Abstract There are numerous water features on the Canadian landscapes that are not monitored. Specifically, there are water bodies over the prairies and Canadian shield regions of North America that are ephemeral in nature and could have a significant influence on convective storm generation and local weather patterns through turbulent exchanges of sensible and latent heat between the land and the atmosphere. In this study a series of numerical experiments is performed with Environment and Climate Change Canada’s Global Environmental Multiscale (GEM) model at 2.5-km grid spacing to examine the sensitivity of the atmospheric boundary layer and the resulting precipitation to the presence of open water bodies. Operationally, the land–water fraction in GEM is specified by means of static geophysical databases that do not change with time. Uncertainty is introduced in this study into this land–water fraction and the sensitivity of the resulting precipitation is quantified for a convective precipitation event occurring over the Canadian Prairies in the summer of 2014. The results indicate that with an increase in open water bodies, accumulated precipitation, peak precipitation amounts, and intensities decrease. Moreover, shifts are seen in times of peak for both precipitation amounts and intensities, in the order of increasing wetness. Additionally, with an increase in open water bodies, convective available potential energy decreases and convective inhibition increases, indicating suppression of forcing for convective precipitation.

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Model Predictive Control of a River Reach with Weirs

10.29007/1nnf ◽

2018 ◽

Author(s):

Klaudia Horváth ◽

Bart van Esch ◽

Jorn Baayen ◽

Ivo Pothof ◽

Jan Talsma ◽

...

Keyword(s):

Decision Support ◽

Convex Optimization ◽

Decision Support System ◽

Model Predictive Control ◽

Predictive Control ◽

Support System ◽

Water System ◽

Open Water ◽

Global Optimum ◽

Water Levels

A decision support system for water management based on convex optimization, RTC-Tools 2, is applied for a water system containing river branches connected by weirs. The advantage of convex optimization is the ability of finding the global optimum, which makes the decision support system robust and deterministic. In this work the convex modeling of open water channels and weirs is presented. The decision support system is implemented for a river made of 12 river reaches divided by movable weirs. It is shown how the discharge wave is dispatched in the river without the water levels exceeding the bounds by controlling the weir heights. After this test the optimization can be applied to a realistic numerical model and model predictive control can be implemented.

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Regulation of Vegetation and Evapotranspiration by Water Level Fluctuation in Shallow Lakes

Water ◽

10.3390/w13192651 ◽

2021 ◽

Vol 13 (19) ◽

pp. 2651

Author(s):

Qiang Liu ◽

Liqiao Liang ◽

Xiaomin Yuan ◽

Sirui Yan ◽

Miao Li ◽

...

Keyword(s):

Water Level ◽

Open Water ◽

Water Area ◽

Water Level Fluctuation ◽

Water Levels ◽

Water Level Fluctuations ◽

Water Evaporation ◽

Level Fluctuation ◽

Open Water Area ◽

Annual Scale

Water level fluctuations play a critical role in regulating vegetation distribution, composition, cover and richness, which ultimately affect evapotranspiration. In this study, we first explore water level fluctuations and associated impacts on vegetation, after which we assess evapotranspiration (ET) under different water levels. The normalized difference vegetation index (NDVI) was used to estimate the fractional vegetation cover (Fv), while topography- and vegetation-based surface-energy partitioning algorithms (TVET model) and potential evaporation (Ev) were used to calculate ET and water evaporation (Ep). Results show that: (1) water levels were dramatically affected by the combined effect of ecological water transfer and climate change and exhibited significant decreasing trends with a slope of −0.011 m a−2; and (2) as predicted, there was a correlation between water level fluctuation at an annual scale with Phragmites australis (P. australis) cover and open-water area. Water levels also had a controlling effect on Fv values, an increase in annual water levels first increasing and then decreasing Fv. However, a negative correlation was found between Fv values and water levels during initial plant growth stages. (iii) ET, which varied under different water levels at an annual scale, showed different partition into transpiration from P. australis and evaporation from open-water area and soil with alterations between vegetation and open water. All findings indicated that water level fluctuations controlled biological and ecological processes, and their structural and functional characteristics. This study consequently recommends that specifically-focused ecological water regulations (e.g., duration, timing, frequency) should be enacted to maintain the integrity of wetland ecosystems for wetland restoration.

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Predicting Water Availability in Water Bodies under the Influence of Precipitation and Water Management Actions Using VAR/VECM/LSTM

Climate ◽

10.3390/cli9090144 ◽

2021 ◽

Vol 9 (9) ◽

pp. 144

Author(s):

Harleen Kaur ◽

Mohammad Afshar Alam ◽

Saleha Mariyam ◽

Bhavya Alankar ◽

Ritu Chauhan ◽

...

Keyword(s):

Water Management ◽

Short Term Memory ◽

Forecast Error ◽

Error Variance ◽

Water Levels ◽

Water Bodies ◽

Economic Activities ◽

Management Actions ◽

Forecast Error Variance ◽

Water Treatments

Recently, awareness about the significance of water management has risen as population growth and global warming increase, and economic activities and land use continue to stress our water resources. In addition, global water sustenance efforts are crippled by capital-intensive water treatments and water reclamation projects. In this paper, a study of water bodies to predict the amount of water in each water body using identifiable unique features and to assess the behavior of these features on others in the event of shock was undertaken. A comparative study, using a parametric model, was conducted among Vector Autoregression (VAR), the Vector Error Correction Model (VECM), and the Long Short-Term Memory (LSTM) model for determining the change in water level and water flow of water bodies. Besides, orthogonalized impulse responses (OIR) and forecast error variance decompositions (FEVD) explaining the evolution of water levels and flow rates, the study shows the significance of VAR/VECM models over LSTM. It was found that on some water bodies, the VAR model gave reliable results. In contrast, water bodies such as water springs gave mixed results of VAR/VECM.

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Ist Wasserbau auch eine Frage der Ästhetik? | Is hydraulic engineering a question of aesthetics?

Schweizerische Zeitschrift fur Forstwesen ◽

10.3188/szf.2008.0205 ◽

2008 ◽

Vol 159 (7) ◽

pp. 205-208

Author(s):

Gianni Paravicini

Keyword(s):

Open Water ◽

Hydraulic Engineering ◽

Water Bodies ◽

Ecological Value ◽

The Aesthetic ◽

Bodies Of Water

There is much extended literature about classic technical hydraulic engineering and about the revitalization of bodies of water. This article deals with a third component, which has received little attention by the engineers. The author pleads for more aesthetic in hydraulic engineering, in particular in populated areas where many people use the open water bodies for recreation. It is shown that more aesthetic in hydrologic engineering often also leads to an increased ecological value. With hydraulic constructions in the canton of Lueerne, possible creative elements for the aesthetic and ecological revaluation of the course of creeks are discussed.

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A multi-temporal remote sensing approach for monitoring changes in spatial extent of freshwater lake of Deepor Beel Ramsar Site, a major wetland of Assam

Journal of Wetlands Ecology ◽

10.3126/jowe.v5i0.4696 ◽

2011 ◽

Vol 5 ◽

pp. 40-47 ◽

Cited By ~ 10

Author(s):

Jyotishman Deka ◽

Om Prakash Tripathi ◽

Mohammad Latif Khan

Keyword(s):

Open Water ◽

Management Plan ◽

Rate Of Change ◽

Freshwater Lake ◽

Landsat Tm ◽

Water Bodies ◽

Food Storage ◽

Data Mapping ◽

Wetland Ecosystem ◽

Rapid Urbanization

Sustainability of wetland ecosystem is necessary for various important functions such as food storage, water quality continuation and providing habitat for different species of flora and fauna. Hence, an inventory of wetlands of any region is a pre-requisite for their conservation and management. This study has been carried out to delineate the change in freshwater lake of ‘Deepor Beel’ wetland of Assam, India, using LANDSAT TM data. Field observation shows that the ecosystem is facing both natural as well as anthropogenic threats. Rapid urbanization, Illegal settlements, industries, invasive species (Eichhornia crassipes) are the major cause of this wetland decline. It has been found that massive decline occurred between the period 1991 to 2001 i.e., 1.891 sq.km which was at the rate of -0.171 per year where as the decline between the period 2001 to 2010 was found to be 1.013 sq. km which was at a rate of -0.101. The total area of open water bodies has decreased by 2.904 sq. km from 1991 to 2010 i.e. 59.19%. Thus the overall rate of change in the water bodies from 1991 to 2010 to other land use categories was found to be -0.145. Hence the study reveals the potentiality of Landsat TM data mapping the change in the wetland ecosystem. It is further hoped that the study will have high utility in preparing management plan for conservation of this ecosystem. Keywords: Wetland; Landsat TM; Thresholding; density sliceDOI: http://dx.doi.org/10.3126/jowe.v5i0.4696 J Wet Eco 2011 (5): 40-47

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