Water Level Fluctuation in a Northeastern Ontario Peatland

1974 ◽  
Vol 4 (1) ◽  
pp. 76-81 ◽  
Author(s):  
T. S. Dai ◽  
V. F. Haavisto ◽  
J. H. Sparling
Keyword(s):  
Water Level ◽  
Narrow Range ◽  
Black Spruce ◽  
Heavy Rain ◽  
High Water ◽  
Water Levels ◽  
Level Fluctuation ◽  
Local Climate ◽  
Poor Fen ◽  
Run Off

Depths to water level and changes due to local climate were dissimilar in five peatland conditions in northeastern Ontario. The deepest water level and the greatest fluctuations occurred in an ombrotrophic black spruce bog site. The sedge-dominated poor fen site was submerged following every heavy rain. Waterlogged conditions remained within 6 cm of the surface at all times because of the influence by the water level of Dai Lake. The water level of Dai Lake varied within a narrow range because the loss of water was primarily dependent on slow seepage and evaporation. The lagg site was affected by continuous inflow, high water levels, and fast run-off, therefore, a larger fluctuation of water level prevailed at this site.

Lake and inland dunes as interconnected Systems: The story of Lake Tresssee and an adjacent dune field (Schleswig-Holstein, North Germany)

The Holocene ◽  
2020 ◽  
pp. 095968362098168
Author(s):  
Christian Stolz ◽  
Magdalena Suchora ◽  
Irena A Pidek ◽  
Alexander Fülling
Keyword(s):  
Water Level ◽  
Bronze Age ◽  
Environmental Changes ◽  
High Water ◽  
Alluvial Fan ◽  
Water Levels ◽  
Lake Area ◽  
Dune Field ◽  
The North ◽  
Sand Drift

The specific aim of the study was to investigate how four adjacent geomorphological systems – a lake, a dune field, a small alluvial fan and a slope system – responded to the same impacts. Lake Tresssee is a shallow lake in the North of Germany (Schleswig-Holstein). During the Holocene, the lake’s water surface declined drastically, predominately as a consequence of human impact. The adjacent inland dune field shows several traces of former sand drift events. Using 30 new radiocarbon ages and the results of 16 OSL samples, this study aims to create a new timeline tracing the interaction between lake and dunes, as well, as how both the lake and the dunes reacted to environmental changes. The water level of the lake is presumed to have peaked during the period before the Younger Dryas (YD; start at 10.73 ka BC). After the Boreal period (OSL age 8050 ± 690 BC) the level must have undergone fluctuations triggered by climatic events and the first human influences. The last demonstrable high water level was during the Late Bronze Age (1003–844 cal. BC). The first to the 9th century AD saw slightly shrinking water levels, and more significant ones thereafter. In the 19th century, the lake area was artificially reduced to a minimum by the human population. In the dunes, a total of seven different phases of sand drift were demonstrated for the last 13,000 years. It is one of the most precisely dated inland-dune chronologies of Central Europe. The small alluvial fan took shape mainly between the 13th and 17th centuries AD. After 1700 cal. BC (Middle Bronze Age), and again during the sixth and seventh centuries AD, we find enhanced slope activity with the formation of Holocene colluvia.

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

Water ◽  
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.

The effect of ground water-level on the yield of some common crops on a fen peat soil

1958 ◽  
Vol 50 (3) ◽  
pp. 243-252 ◽  
Author(s):  
H. H. Nicholson ◽  
D. H. Firth
Keyword(s):  
Ground Water ◽  
Water Level ◽  
Peat Soil ◽  
Good Condition ◽  
High Water ◽  
Water Levels ◽  
Ground Water Level ◽  
Potential Evaporation ◽  
Soil Moisture Deficit ◽  
Moisture Deficit

An account is given of a field experiment in the control of ground water-level in a Fen peat soil, together with its results on the yields of crops in a six-course rotation.The seasonal variations in rainfall are presented in terms of potential evaporation and soil moisture deficit. The effect of the water-level on the moistness of the soil above it is indicated. Even in a wet summer, drying was perceptible within 18–20 in. of the ground water-level between successive falls of rain.The fluctuations of the ground water-levels are discussed. Those of the high water-levels were chiefly due to individual incidences of rain causing rises short in duration, but sufficient in the case of water-levels within 20 in. of the surface to cause total waterlogging and surface ponding. Those of the deep water-levels were most influenced by evaporation, with steady and persistent falls during any rain-free period.The deterioration of the physical condition of the soil over high water-levels is shown in the result of sieving tests. In 6 years the loss of tilth over waterlevels within 20 in. of the surface was very marked and was discernible over those as low as 30 in.The possibilities of effectively using high ground water-levels occasionally in soils in good condition are shown by the results with celery and potatoes.

Selecting velocity fields in urban pluvial floods from pre-calculated data

2020 ◽  
Author(s):  
Robert Sämann ◽  
Thomas Graf ◽  
Insa Neuweiler
Keyword(s):  
High Resolution ◽  
Water Level ◽  
Mean Square Error ◽  
Nearest Neighbor ◽  
Calculated Data ◽  
Velocity Fields ◽  
Water Levels ◽  
Mean Square ◽  
Run Off

<p><span>Early warning systems for floods in urban areas should forecast water levels and damage estimation to protect vulnerable regions. To estimate the danger of a flood for buildings and people, the energy of the flood has to be taken into account additionally to the water level. The energy is related to the flow velocity. For directing rescue workers or trace spreading of contaminants through flooded streets, a high resolution of the water’s energy in space and time is required. Direct numerical run-off calculation is too slow for a flood forecast in time. Therefore a database with pre-calculated events is needed and a method to select the water levels and velocity fields that are similar to a forecasted rain event. </span></p><p><span>We present a method, how to create a real-time forecast based on pre-calculated data. The selection and weighting of the pre-calculated data is based on the precipitation pattern in the flood region. A nearest neighbor approach is applied to find water levels and velocity fields from a database that are similar to the forecasting event. For the ranking of similarity, different new metrics are compared against each other. The quality of the metrics is tested with a new approach of comparing velocity fields on the surface and in the pipe system. Considering both domains is crucial for understanding the complex dynamic flow paths on the surface. An urban catchment of 5 km² with high resolution (~3 m³) triangular surface mesh and connected drainage system is used for a hydrodynamic run-off simulation. The 1D-2D coupled software HYSTEM EXTRAN is used to generate the water levels and velocity fields for strong rainfall events of the past 20 years. More than 900 events with a duration between 15 minutes and 24 hours and return periods between 10 and 100 years were calculated and stored as the “pre-calculated” dataset.</span></p><p><span>For comparing two events, the mean square error is calculated between the precipitation patterns with different approaches to select the start index and number of intervals. This number depends on the hydraulic response time, the temporal resolution and the length of the reference pattern. The quality of the nearest neighbor selection is quantified using the Nash–Sutcliffe model efficiency coefficient of pipe flow and the root mean square error of water level and velocity in significant surface cells. Additionally, the transport paths of artificial contamination spills are compared between the events to show the reproducibility of velocity fields for each metric. </span></p><p><span>Results show that the reaction time and the wetting state of the surface is very important. Single cell values correspond well between a forecasted and a dataset event. However, complex transport paths have a very high variability that is not reproducible with similar events. Further research is required to clarify if this is a result of the random walk approach or of the injection time of the particles. </span></p>

Uncertainty in coastal flooding: modelling and visualisation

2020 ◽  
Author(s):  
John Maskell
Keyword(s):  
Water Level ◽  
Storm Surge ◽  
Return Period ◽  
Flood Risk ◽  
High Water ◽  
Coastal Flooding ◽  
Water Levels ◽  
Tidal Range ◽  
The Uk ◽  
Flood Maps

<p>Two case studies are considered in the UK, where uncertainty and drivers of coastal flood risk are explored through modelling and visualisations. Visualising the impact of uncertainty is a useful way of explaining the potential range of predicted or simulated flood risk to both expert and non-expert stakeholders.</p><p>Significant flooding occurred in December 2013 and January 2017 at Hornsea on the UK East Coast, where storm surge levels and waves overtopped the town’s coastal defences. Uncertainty in the potential coastal flooding is visualised at Hornsea due to the range of uncertainty in the 100-year return period water level and in the calculated overtopping due to 3 m waves at the defences. The range of uncertainty in the simulated flooding is visualised through flood maps, where various combinations of the uncertainties decrease or increase the simulated inundated area by 58% and 82% respectively.</p><p>Located at the mouth of the Mersey Estuary and facing the Irish Sea, New Brighton is affected by a large tidal range with potential storm surge and large waves. Uncertainty in the coastal flooding at the 100-year return period due to the combination of water levels and waves is explored through Monte-Carlo analysis and hydrodynamic modelling. Visualisation through flood maps shows that the inundation extent at New Brighton varies significantly for combined wave and surge events with a joint probability of 100 years, where the total flooded area ranges from 0 m<sup>2</sup> to 10,300 m<sup>2</sup>. Waves are an important flood mechanism at New Brighton but are dependent on high water levels to impact the coastal defences and reduce the effective freeboard. The combination of waves and high-water levels at this return level not only determine the magnitude of the flood extent but also the spatial characteristics of the risk, whereby flooding of residential properties is dominated by overflow from high water levels, and commercial and leisure properties are affected by large waves that occur when the water level is relatively high at the defences.</p>

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.

Water Movement Rule and Quality Assessment of Overflow in the Zhenjiang Neijiang

2014 ◽  
Vol 1010-1012 ◽  
pp. 821-825
Author(s):  
Song Mei Wang ◽  
Chun Du Wu ◽  
Jin Yu Chu ◽  
Qing Jie Xie
Keyword(s):  
Waste Water ◽  
Correlation Analysis ◽  
Quality Assessment ◽  
Water Level ◽  
Water Movement ◽  
Pollution Index ◽  
Water Quality Assessment ◽  
High Water ◽  
Water Levels ◽  
High Water Level

We perform a study of the waste water from overflow in the Zhenjiang Neijiang . Determine content of COD、NH3-N、TP which changing along the distance at different water levels . Based on the SPSS14.0 correlation analysis , single factor pollution index and the comprehensive pollution index we study water movement rule and quality assessment. The results showed that : At low water level COD、NH3-N、TP decrease alleviation, the whole datum are high; at high water level COD、NH3-N、TP decrease greatly between 0~7m,but decrease alleviation between 7~200m. (2) Only the content of NH3-N (0~7m ) has significant differences (p<0.05),the other content all has not significant differences (p>0.05), the waste water from overflow was seriously polluted so that the wetland can not purify it adequately. (3)Based on the Vwater quality grade standard, at low water level the content of COD、NH3-N、TP(0~200m ) are all beyond standard; at high water level the content of COD、NH3-N、TP(80~200m ) are all beyond standard; the order of the potential ecological rick is: NH3-N>TP>COD. The study on the datum could offer a favorable plan for purifying the waste water from overflow in the Zhenjiang Neijiang. Keyword: overflow; water movement rule; correlation analysis; water quality assessment

scholarly journals Morphology of the Invasive Amphiphyte Alternanthera Philoxeroides Under Different Water Levels and Nitrogen Concentrations

2015 ◽  
Vol 56 (2) ◽  
pp. 136-147 ◽  
Author(s):  
Wenjuan Ding ◽  
Huayong Zhang ◽  
Fangjuan Zhang ◽  
Lijun Wang ◽  
Songbo Cui
Keyword(s):  
Water Level ◽  
Inorganic Nitrogen ◽  
Water Level Fluctuation ◽  
Water Levels ◽  
Alternanthera Philoxeroides ◽  
Polluted Water ◽  
Level Fluctuation ◽  
High Nitrogen ◽  
Nitrogen Concentrations ◽  
Clonal Spread

Abstract Water level fluctuation and inorganic nitrogen enrichment are two serious problems caused by anthropogenic disturbances in aquatic ecosystems. They cause resource fluctuation and thus might influence the invasive-ness of alien plants. Alternanthera philoxeroides is an amphibious and widespread clonal plant which exhibits significant invasiveness. This experimental study examined the plant's morphological traits under different nitrogen concentrations and water levels. The responses of A. philoxeroides to water levels and nitrogen concentrations were similar for both land-like and riverbank-like initial conditions. A. philoxeroides showed an escape strategy of shoot elongation when its growth was suppressed by shallow submergence. No toxic symptoms but increased clonal spread was observed at high nitrogen concentrations, suggesting that A. philoxeroides not only tolerated but benefitted from nitrogen-polluted water. High nitrogen level mitigated the negative effects of submergence on its leaf survival, thereby enhancing its adaptation to water level fluctuation. Such strong adaptability and clonal spread helps A. philoxeroides to grow and invade successfully in shallow eutrophic water.

scholarly journals Hydrometeorological drivers of flood characteristics in the Brahmaputra river basin in Bangladesh

2021 ◽  
Author(s):  
Sazzad Hossain ◽  
Hannah L. Cloke ◽  
Andrea Ficchì ◽  
Andrew G. Turner ◽  
Elisabeth M. Stephens
Keyword(s):  
Water Level ◽  
Morphological Changes ◽  
High Water ◽  
Water Levels ◽  
Future Climate Change ◽  
South Asian Summer Monsoon ◽  
Large Variability ◽  
Long Duration ◽  
The Impact ◽  
Flood Characteristics

Abstract. While flooding is an annual occurrence in the Brahmaputra basin during the South Asian summer monsoon, there is large variability in the flood characteristics that drive risk: flood duration, rate of water level rise and peak water level. The aim of this study is to understand the key hydrometeorological drivers influencing these flood characteristics. We analyse hydrometeorological time series of the last 33 years to understand flood dynamics focusing on three extraordinary floods in 1998 (long duration), 2017 (rapid rise) and 2019 (high water level). We find that long duration floods in the basin have been driven by basin-wide seasonal rainfall extremes associated with the development phase of strong La Niña events, whereas floods with a rapid rate of rise have been driven by more localized rainfall falling in a hydrological ‘sweet spot’ that leads to a concurrent contribution from the tributaries into the main stem of the river. We find that recent record high water levels are not coincident with extreme river flows, hinting that sedimentation and morphological changes are also important drivers of flood risk that should be further investigated. Understanding these drivers is essential for flood forecasting and early warning and also to study the impact of future climate change on flood.

scholarly journals Causes of the Transboundary Lake Khanka Extreme High Water Level

2016 ◽  
pp. 62
Author(s):  
Keyword(s):  
Water Level ◽  
Lake Level ◽  
High Water ◽  
Water Levels ◽  
Anthropogenic Factors ◽  
Economic Activities ◽  
Republic Of China ◽  
High Water Level ◽  
Level Regime ◽  
Lake Khanka

Reasons of the extremely high water level in Lake Khanka (it was 0.5 m higher the historical maximum over the past years) have been revealed within the frameworks of the carried out exploration. The lake capacity characteristics alteration due to the natural and anthropogenic factors’ impact has been assessed. We have considered the factors that form the Lake Khanka level regime, i.e. natural: atmosphere circulation, atmospheric perspiration, river inflow to the lake, evaporation from the lake surface, and outflow; anthropogenic: economic activities on the catchment on Russian and Chinese territories (hydro/melioration and the runoff transfer). The passage capacity of the Sungachi River, the only outflow from the lake, has been analyzed in details at different water levels in Lake Khanka. The paper is based on summing up and analysis of information on the lake hydro/meteorological regime and economic activities on its catchment, as well as reference literature. As a result of the study the authors for the first time has identified the main reason of the abnormal rise of the Kanka level. It was found that the significant transformation of the lake level regime occurred due to the Mulinkhe Rivers runoff transfer to Lake Malaya Khanka from the People’s Republic of China. A forecast of the lake level for 2016 taking into consideration different scenarios of the basin moistening has been given. In connection with the forecasted rise of the water level in Lake Khanka in the nearest future we propose a number of measures aimed to minimize inevitable damage to the Russian party.

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