scholarly journals What Caused Record Water Level Rise in the Great Lakes?

Eos ◽  
2016 ◽  
Vol 97 ◽  
Author(s):  
Terri Cook
Keyword(s):  
Great Lakes ◽  
Water Level ◽  
Water Levels ◽  
Climate Trends ◽  
Modeling Framework ◽  
Water Level Rise ◽  
Short And Long Term ◽  
Insight Into

A new modeling framework offers insight into how specific lakes' water levels respond to short- and long-term climate trends.

The influence of immersed water level on the short- and long-term mechanical behavior of sandstone

2021 ◽  
Vol 138 ◽  
pp. 104631
Author(s):  
Peizhao Chen ◽  
Shibin Tang ◽  
Xin Liang ◽  
Yongjun Zhang ◽  
Chunan Tang
Keyword(s):  
Mechanical Behavior ◽  
Water Level ◽  
Short And Long Term

Sedimentary Cladocera as indicators of past water-level changes in shallow northern lakes

2011 ◽  
Vol 75 (3) ◽  
pp. 430-437 ◽  
Author(s):  
Liisa Nevalainen ◽  
Kaarina Sarmaja-Korjonen ◽  
Tomi P. Luoto
Keyword(s):  
Water Level ◽  
Lake Level ◽  
Water Levels ◽  
Sediment Record ◽  
Inference Model ◽  
Water Level Changes ◽  
Long Term Changes ◽  
Lower Water Level ◽  
The Relationship

AbstractThe usability of subfossil Cladocera assemblages in reconstructing long-term changes in lake level was examined by testing the relationship between Cladocera-based planktonic/littoral (P/L) ratio and water-level inference model in a surface-sediment dataset and in a 2000-yr sediment record in Finland. The relationships between measured and inferred water levels and P/L ratios were significant in the dataset, implying that littoral taxa are primarily deposited in shallow littoral areas, while planktonic cladocerans accumulate abundantly mainly in deepwater locations. The 2000-yr water-level reconstructions based on the water-level inference model and P/L ratio corresponded closely with each other and with a previously available midge-inferred water-level reconstruction from the same core, showing a period of lower water level around AD 300–1000 and suggesting that the methods are valid for paleolimnological and -climatological use.

Long-Term Tidal Water Level Measurements in Abu Dhabi Emirate

2008 ◽  
Author(s):  
Khaled A. Mohamed
Keyword(s):  
Water Level ◽  
Water Levels ◽  
Abu Dhabi ◽  
Tidal Analysis ◽  
Tidal Motion ◽  
Tidal Water ◽  
Abu Dhabi Emirate ◽  
Tidal Constituents ◽  
Water Level Measurements

Abu Dhabi Emirate, United Arab Emirates has a unique tidal system. Understanding the tidal hydrodynamics in Abu Dhabi waters is very important for the design of the hydraulic structures and in the marine environmental studies. The objective of this study is to investigate the tidal water levels and tidal motion in Abu Dhabi, making use of the long-term water levels available. To achieve the aim of the study, the National Energy and Water Research Center (NEWRC) of Abu Dhabi Water and Electricity Authority installed tidal gauges at different locations in Abu Dhabi waters to obtain long-term water level measurements. At present, long-term water level measurements for at least 3 years period are available at different locations in Abu Dhabi waters. Tidal analysis was carried out on the available data to determine the characteristics of the tidal wave in Abu Dhabi Emirate and to get the main tidal constituents affecting the tidal motion. The obtained tidal constituents are used in updating and improving the boundary conditions of the numerical hydrodynamic models simulating the flow pattern in Abu Dhabi waters. The set up of the water level measurement program in Abu Dhabi waters and the results of the tidal analysis are presented and discussed in the paper.

From pristine to present state: hydrology evolution of Lake Saint-François, St. Lawrence River

1998 ◽  
Vol 25 (5) ◽  
pp. 864-879 ◽  
Author(s):  
Jean Morin ◽  
Michel Leclerc
Keyword(s):  
Water Level ◽  
Plant Biomass ◽  
Seasonal Pattern ◽  
Water Levels ◽  
Ship Traffic ◽  
Water Level Rise ◽  
Hydropower Production ◽  
Discharge Regulation ◽  
The Impact ◽  
St Lawrence River

Lake Saint-François is a relatively shallow fluvial lake of the St. Lawrence River with numerous deep channels. This complex system has been considerably altered from its pristine state 150 years ago. Currently, the water level is stabilized and the flow is regulated; important areas have been dredged and the major part of its outflow is diverted through the Beauharnois canal. The evolution of water levels shows a trend towards stabilization as required for ship traffic in the St. Lawrence Seaway and for hydropower production. With the construction of the Moses-Saunders dam in 1960, the flow of the river could be regulated; changes occur in the seasonal pattern of the flow. Ancient stage-discharge relationships were recreated to describe the impact of the 1849 damming and of the present level stabilization. Stabilization of the water level has favored the growth of submerged plants. Manning's friction coefficient was used to show that plant biomass has doubled since 1920; the onset of biomass increases corresponds to a water level stabilization event. The distribution of wetlands in the Lake Saint-François area was drastically modified by the water level rise caused by the 1849 damming. New wetlands were created and pre-1849 wetlands, located on what are currently shoals in the central part of the lake, have totally disappeared.Key words: Lake Saint-François, St. Lawrence River, impact of civil works, flow discharge regulation, water level regulation, wetland flooding cycle, submerged macrophyte, ecosystem reaction, civil work history.

scholarly journals Flooding dynamics in a large low-gradient alluvial fan, the Okavango Delta, Botswana, from analysis and interpretation of a 30-year hydrometric record

2005 ◽  
Vol 2 (5) ◽  
pp. 1865-1892 ◽  
Author(s):  
P. Wolski ◽  
M. Murray-Hudson
Keyword(s):  
Local Population ◽  
Tourism Industry ◽  
Alluvial Fan ◽  
Water Levels ◽  
Okavango Delta ◽  
Complex Interplay ◽  
Flood Dynamics ◽  
The Given ◽  
Insight Into

Abstract. The Okavango Delta is a flood-pulsed wetland, the resources of which support a large tourism industry and subsistence of the local population. In order to obtain an insight into the influence of various environmental factors on flood propagation and distribution in this system, an analysis was undertaken of a 30-year record of hydrometric data (discharges and water levels) from one of the Delta distributaries. The analysis revealed that water levels and discharges at any given channel site in the analysed distributary are influenced by a complex interplay of flood wave and local rainfall input modified by channel-floodplain interactions, in-channel sedimentation and technical interventions, both at the given site and upstream. Additionally, cyclical variation of channel margin vegetation due to nutrients recycling might play a role. It was shown that data from channels do not adequately represent flood dynamics and its change at the distributary level. The paper contributes to the understanding of seasonal and long-term flood pulsing and their changes in low gradient systems of channels and floodplains.

scholarly journals Characterising hillslope–stream connectivity with a joint event analysis of stream and groundwater levels

2020 ◽  
Vol 24 (12) ◽  
pp. 5713-5744
Author(s):  
Daniel Beiter ◽  
Markus Weiler ◽  
Theresa Blume
Keyword(s):  
Time Series ◽  
Water Level ◽  
Groundwater Level ◽  
Stream Water ◽  
Water Levels ◽  
Joint Analysis ◽  
Strong Increase ◽  
Groundwater Levels ◽  
The Relationship ◽  
Insight Into

Abstract. Hillslope–stream connectivity controls runoff generation, during events and during baseflow conditions. However, assessing subsurface connectivity is a challenging task, as it occurs in the hidden subsurface domain where water flow can not be easily observed. We therefore investigated if the results of a joint analysis of rainfall event responses of near-stream groundwater levels and stream water levels could serve as a viable proxy for hillslope–stream connectivity. The analysis focuses on the extent of response, correlations, lag times and synchronicity. As a first step, a new data analysis scheme was developed, separating the aspects of (a) response timing and (b) extent of water level change. This provides new perspectives on the relationship between groundwater and stream responses. In a second step we investigated if this analysis can give an indication of hillslope–stream connectivity at the catchment scale. Stream water levels and groundwater levels were measured at five different hillslopes over 5 to 6 years. Using a new detection algorithm, we extracted 706 rainfall response events for subsequent analysis. Carrying out this analysis in two different geological regions (schist and marls) allowed us to test the usefulness of the proxy under different hydrological settings while also providing insight into the geologically driven differences in response behaviour. For rainfall events with low initial groundwater level, groundwater level responses often lag behind the stream with respect to the start of rise and the time of peak. This lag disappears at high antecedent groundwater levels. At low groundwater levels the relationship between groundwater and stream water level responses to rainfall are highly variable, while at high groundwater levels, above a certain threshold, this relationship tends to become more uniform. The same threshold was able to predict increased likelihood for high runoff coefficients, indicating a strong increase in connectivity once the groundwater level threshold was surpassed. The joint analysis of shallow near-stream groundwater and stream water levels provided information on the presence or absence and to a certain extent also on the degree of subsurface hillslope–stream connectivity. The underlying threshold processes were interpreted as transmissivity feedback in the marls and fill-and-spill in the schist. The value of these measurements is high; however, time series of several years and a large number of events are necessary to produce representative results. We also find that locally measured thresholds in groundwater levels can provide insight into the connectivity and event response of the corresponding headwater catchments. If the location of the well is chosen wisely, a single time series of shallow groundwater can indicate if the catchment is in a state of high or low connectivity.

scholarly journals Wave Climate Associated With Changing Water Level and Ice Cover in Lake Michigan

2021 ◽  
Vol 8 ◽  
Author(s):  
Chenfu Huang ◽  
Longhuan Zhu ◽  
Gangfeng Ma ◽  
Guy A. Meadows ◽  
Pengfei Xue
Keyword(s):  
Climate Change ◽  
Water Level ◽  
Lake Michigan ◽  
Linear Trend ◽  
Ice Cover ◽  
Wave Climate ◽  
Water Levels ◽  
Regional Warming ◽  
Model Simulations

Detailed knowledge of wave climate change is essential for understanding coastal geomorphological processes, ecosystem resilience, the design of offshore and coastal engineering structures and aquaculture systems. In Lake Michigan, the in-situ wave observations suitable for long-term analysis are limited to two offshore MetOcean buoys. Since this distribution is inadequate to fully represent spatial patterns of wave climate across the lake, a series of high-resolution SWAN model simulations were performed for the analysis of long-term wave climate change for the entirety of Lake Michigan from 1979 to 2020. Model results were validated against observations from two offshore buoys and 16 coastal buoys. Linear regression analysis of significant wave height (Hs) (mean, 90th percentile, and 99th percentile) across the entire lake using this 42-year simulation suggests that there is no simple linear trend of long-term changes of Hs for the majority (>90%) of the lake. To address the inadequacy of linear trend analysis used in previous studies, a 10-year trailing moving mean was applied to the Hs statistics to remove seasonal and annual variability, focusing on identifying long-term wave climate change. Model results reveal the regime shifts of Hs that correspond to long-term lake water level changes. Specifically, downward trends of Hs were found in the decade of 1990–2000; low Hs during 2000–2010 coincident with low lake levels; and upward trends of Hs were found during 2010–2020 along with rising water levels. The coherent pattern between the wave climate and the water level was hypothesized to result from changing storm frequency and intensity crossing the lake basin, which influences both waves (instantly through increased wind stress on the surface) and water levels (following, with a lag through precipitation and runoff). Hence, recent water level increases and wave growth were likely associated with increased storminess observed in the Great Lakes. With regional warming, the decrease in ice cover in Lake Michigan (particularly in the northernmost region of the lake) favored the wave growth in the winter due to increased surface wind stress, wind fetch, and wave transmission. Model simulations suggest that the basin-wide Hs can increase significantly during the winter season with projected regional warming and associated decreases in winter ice cover. The recent increases in wave height and water level, along with warming climate and ice reduction, may yield increasing coastal damages such as accelerating coastal erosion.

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