scholarly journals Meteorological Controls on Water Table Dynamics in Fen Peatlands Depend on Management Regimes

2021 ◽  
Vol 9 ◽  
Author(s):  
Sate Ahmad ◽  
Haojie Liu ◽  
Shajratul Alam ◽  
Anke Günther ◽  
Gerald Jurasinski ◽  
...  
Keyword(s):  
Water Table ◽  
Meteorological Factors ◽  
Meteorological Conditions ◽  
Ecosystem Functions ◽  
Specific Yield ◽  
Vegetation Development ◽  
Effective Measure ◽  
Water Storage Capacity ◽  
Water Tables ◽  
The Impact

Fens belong to the most threatened ecosystems in Europe. Maintaining a high water table through rewetting is an effective measure to rehabilitate many of their ecosystem functions. However, the impact of meteorological conditions such as vapor pressure deficit (VPD) and precipitation on water tables is still unclear for rewetted fens. Here, we compare the impact of meteorological factors on water table dynamics in a drained and a rewetted fen, using multiple regression with data from continuous high-resolution (temporal) water level monitoring and weather stations. We find that an increase in the daily mean VPD causes a higher drop in the water table at the drained and degraded fen compared to the rewetted fen. Precipitation contributes to recharge, causing the water table to rise higher at the drained site than at the rewetted site. We attribute the differential influence of meteorological conditions on water table dynamics to different soil specific yield values (i.e., water storage capacity) largely driven by lower water table position at the drained site. Our study underlines the importance of understanding how and why water tables in peatlands vary in response to meteorological factors for management decisions (e.g., rewetting). Continuous monitoring of water table and vegetation development in rewetted fen peatlands is advisable to ensure long-term success especially under climate change conditions and associated drought events.

Long-term rewetting of fen peatlands alters the response of water tables to rainfall and temperature

2021 ◽  
Author(s):  
Sate Ahmad ◽  
Haojie Liu ◽  
Shajratul Alam ◽  
Anke Günther ◽  
Gerald Jurasinski ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Water Table ◽  
Air Temperature ◽  
Meteorological Factors ◽  
Water Storage ◽  
Ecosystem Functions ◽  
Effective Measure ◽  
North East ◽  
The Impact

<p>Fens belong to the most threatened ecosystems in Europe. Maintaining a high water table through rewetting is an effective measure to rehabilitate many of their ecosystem functions. However, the impact of meteorological factors such as relative humidity, precipitation and air temperature on water storage and its dynamics is still unclear especially for rewetted fens in the temperate regions. Here, we quantify the impact of meteorological factors on water table dynamics comparing a drained and a rewetted fen in North-East Germany, using multiple linear regression with data from continuous high-resolution (temporal) water level monitoring and weather stations. We found that a 1-degree rise in daily maximum air temperature causes a drop of about 4 mm in the water table in the drained and degraded fen but only a drop of around 2 mm at the rewetted site, mainly through evapotranspiration. Higher minimum relative humidity limits evapotranspiration and is, thus, negatively associated with water table elevation at both sites. Precipitation contributes to recharge, causing the water table to rise almost six times higher at the drained site than at the rewetted site. We attribute the differential impacts of meteorological factors on water table dynamics to (1) differences in vegetation, which acts as surface control and (2) differences in soil properties. We found that for the depths at which the groundwater fluctuates, the peat of the rewetted fen has a higher specific yield compared to the drained fen, causing the water table to rise or recede at smaller rates. A period of 20 years of rewetting was sufficient to form a new layer of organic matter with a substantial fraction of macropores providing water storage capacity and thereby changing water table response. Our study underlines the importance of long-term rewetting and meteorological factors for peatland restoration. Continuous monitoring of water table and vegetation development in rewetted fens is advisable to ensure long-term success, especially under climate change conditions.</p>

Linking testate amoeba assemblages to paleohydrology and ecosystem function in Holocene peat records from the Hudson Bay Lowlands, Ontario, Canada

The Holocene ◽  
2020 ◽  
pp. 095968362097279
Author(s):  
David Bysouth ◽  
Sarah A Finkelstein
Keyword(s):  
Water Table ◽  
Trophic Position ◽  
Carbon Accumulation ◽  
Ecosystem Functions ◽  
Testate Amoeba ◽  
Hudson Bay ◽  
Accumulation Rates ◽  
Hudson Bay Lowlands ◽  
Water Tables ◽  
Carbon Accumulation Rates

Peat cores from boreal bog and fen sites in the Hudson Bay Lowlands of Northern Ontario, Canada, were analysed to calculate Holocene carbon accumulation rates, and to show how testate amoeba taxonomic assemblages, inferred depths to water table, and four morpho-traits that may be linked to function (mixotrophy, aperture size, aperture position, and biovolume) changed since peatland initiation. Carbon accumulation rates were on average higher for the Holocene in the fen record (19.4 g C m−2 yr−1) in comparison with the bog record (15.7 g C m−2 yr−1), which underwent a fen-to-bog transition around 6900 cal yr BP. Changes in rates of carbon accumulation were most strongly driven by changes in rates of peat vertical accretion, with more rapid rates in the fen record. Carbon accumulation rates were highest following peatland initiation when reconstructed water tables were highest, and in the late Holocene, when water table positions were variable. Taxa with larger biovolumes and apertures were generally more abundant when reconstructed water tables were higher, most notably following peatland initiation. Mixotrophic taxa were more prevalent in drier conditions and in the bog record. Changing frequencies of morpho-traits suggest that testate amoebae may occupy a higher trophic position in the microbial food web during wetter periods, signaling the possibility of internal feedbacks between peatland ecohydrology and critical ecosystem functions including long-term carbon accumulation.

On the occurrence of hypersaline sediments in James Bay coastal marshes

1991 ◽  
Vol 69 (10) ◽  
pp. 2328-2330 ◽  
Author(s):  
Jonathan S. Price
Keyword(s):  
Water Table ◽  
Soil Salinity ◽  
High Water ◽  
Specific Yield ◽  
Organic Layer ◽  
Coastal Marshes ◽  
James Bay ◽  
Vegetation Development ◽  
High Water Table ◽  
Hypersaline Sediments

Measurements of soil salinity, soil moisture, and specific yield, along with depth to the water table, explain the occurrence of a band of hypersaline sediments, ubiquitous along James Bay coastal marshes, that profoundly affects vegetation development. The salinity of the hypersaline zone ranges from 8 g/kg Cl in a southern James Bay marsh, to 28 g/kg in the north, nearly an order of magnitude more than local sediments outside this zone. This common, yet previously unexplained, feature restricts the vegetation development to salt-tolerant species such as Salicornia maritima, Puccinellia phryganodes, and Triglochlin maritimum. The hypersaline zone is rarely inundated by tides, but frequent inundation of the seaward zone maintains a high water table there, with soil salinity, hence vegetation patterns that reflect the ambient tidewater salinity. At sites inland of the hypersaline band the development of an organic layer with a high moisture content supplied by meteoric water and high specific yield maintains relatively fresh water near the surface, imposing minimal salinity restrictions to vegetation. Intermediate to these zones of high water table is the hypersaline band, which has no organic layer and whose surface is not wetted by tides. Its depressed water table causes flow convergence, and the only water sink is through evaporation, which concentrates the salt imported in groundwater. Key words: James Bay, marsh, salinity, hydrology, vegetation.

Drawdowns at the Free Water Table During Pumping Tests in Artesian and Semiartesian Aquifers

1980 ◽  
Vol 11 (3-4) ◽  
pp. 159-168 ◽  
Author(s):  
Henrik Kærgaard
Keyword(s):  
Water Table ◽  
Free Water ◽  
Pumping Test ◽  
Water Withdrawal ◽  
Specific Yield ◽  
Minor Role ◽  
Long Term Effects ◽  
Long Term Storage ◽  
Term Storage

In an earlier paper I have shown an example of how long term drawdowns can be used for the computation of long term storage in artesian and semiartesian areas. In most cases the long term storage is more or less equivalent to the specific yield at the water table; the storage mechanisms of consolidation playing a minor role in long term situations. The specific yield in artesian areas is a very important parameter in the prediction of long term effects of ground water withdrawal. Especially the stream depletion will often mainly be governed by draw-downs in upper nonpumped aquifers near the water table, and these drawdowns depend to a great extent on the specific yield at the water table. A determination of long term storage will often necessitate long term draw-down data, however, under certain circumstances a determination can be made on the basis of a pumping test of limited duration (3-5 weeks) provided drawdown observations at the water table can be made. In this paper some formulas dealing with water table drawdowns in different geohydrologic systems are reviewed, and two cases in which these formulas have been used in practice are presented.

scholarly journals Quantification of Non-Exhaust Particulate Matter Traffic Emissions and the Impact of COVID-19 Lockdown at London Marylebone Road

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 190
Author(s):  
William Hicks ◽  
Sean Beevers ◽  
Anja H. Tremper ◽  
Gregor Stewart ◽  
Max Priestman ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Measurement Data ◽  
Emission Factors ◽  
Meteorological Conditions ◽  
Traffic Emissions ◽  
Atmospheric Particulate Matter ◽  
Exhaust Emission ◽  
Brake Wear ◽  
The Impact ◽  
Exhaust Particulate

This research quantifies current sources of non-exhaust particulate matter traffic emissions in London using simultaneous, highly time-resolved, atmospheric particulate matter mass and chemical composition measurements. The measurement campaign ran at Marylebone Road (roadside) and Honor Oak Park (background) urban monitoring sites over a 12-month period between 1 September 2019 and 31 August 2020. The measurement data were used to determine the traffic increment (roadside–background) and covered a range of meteorological conditions, seasons, and driving styles, as well as the influence of the COVID-19 “lockdown” on non-exhaust concentrations. Non-exhaust particulate matter (PM)10 concentrations were calculated using chemical tracer scaling factors for brake wear (barium), tyre wear (zinc), and resuspension (silicon) and as average vehicle fleet non-exhaust emission factors, using a CO2 “dilution approach”. The effect of lockdown, which saw a 32% reduction in traffic volume and a 15% increase in average speed on Marylebone Road, resulted in lower PM10 and PM2.5 traffic increments and brake wear concentrations but similar tyre and resuspension concentrations, confirming that factors that determine non-exhaust emissions are complex. Brake wear was found to be the highest average non-exhaust emission source. In addition, results indicate that non-exhaust emission factors were dependent upon speed and road surface wetness conditions. Further statistical analysis incorporating a wider variability in vehicle mix, speeds, and meteorological conditions, as well as advanced source apportionment of the PM measurement data, were undertaken to enhance our understanding of these important vehicle sources.

scholarly journals COVID-19 Pandemic Turns Life-Science Students into “Citizen Scientists”: Data Indicate Multiple Negative Effects of Urbanization on Biota

2021 ◽  
Vol 13 (5) ◽  
pp. 2992
Author(s):  
Jens Schirmel
Keyword(s):  
Citizen Science ◽  
Online Teaching ◽  
Teaching Strategy ◽  
Ecosystem Functions ◽  
Negative Effects ◽  
Ecological Data ◽  
Pollinating Insects ◽  
Impact Of Urbanization ◽  
Data Collections ◽  
The Impact

The COVID-19 pandemic and its restrictions strongly affect the higher education community and require diverse teaching strategies. We designed a course where we combined online teaching with independently conducted ecological data collections by students using a “citizen science” approach. The aim was to analyze the impact of urbanization on biota by comparing urban and rural grasslands. Seventy-five students successfully conducted the data collections and the results provide evidence for prevailing negative effects of urbanization. Individual numbers of ground-dwelling invertebrates (−25%) and pollinating insects (−33%) were generally lower in urban sites. Moreover, animal and seed predation were reduced in urban grasslands, indicating the potential of urbanization to alter ecosystem functions. Despite the general limitations of online teaching and citizen science approaches, outcomes of this course showed this combination can be a useful teaching strategy, which is why this approach could be used to more actively involve students in scientific research.

scholarly journals Climatic Analysis of Wind Patterns to Enhance Sailors’ Performance during Races

Climate ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 80
Author(s):  
Pietro Masino ◽  
Roberto Bellasio ◽  
Roberto Bianconi ◽  
Angelo Besana ◽  
Alessandro Pezzoli
Keyword(s):  
Support Service ◽  
Sport Performance ◽  
Meteorological Conditions ◽  
Meteorological Variables ◽  
Wind Data ◽  
Weather Research And Forecasting ◽  
Innovative Method ◽  
Combined Use ◽  
The Impact ◽  
Wind Patterns

The impact of environmental and meteorological conditions when dealing with sport performance has been demonstrated by several studies carried out in recent years. Among the meteorological variables with the greatest effect are temperature, humidity, precipitation, and wind direction and speed. This research focused on analyzing and forecasting the wind patterns occurring in Enoshima Bay (Japan). In particular, the objective of this study was to provide support and guidance to sailors in the preparation of the race strategy, thanks to an in-depth knowledge of these meteorological variables. To do this, an innovative method was used. First, through the combined use of Weather Research and Forecasting (WRF) and CALMET models, a simulation was performed, in order to reconstruct an offshore database of a recent 10-year period (2009–2018) over the race area, inside the bay. Subsequently, the verification of hind-cast was performed: the wind data measured at sea were compared with the data extracted from the CALMET database to verify the validity of the model. The verification was performed through three statistical indexes: BIAS, MAE, and PCC. The analysis showed mixed results, depending on the examined pattern, but made it possible to identify the days that best simulated the reality. Then, the wind data from the selected days were summarized and collected in plots, tables, and maps to design a decision support service (DSS), in order to provide athletes with the necessary information in a simple and effective way. In conclusion, we state that the application of this method extends beyond the sports field. Indeed, the study of wind patterns may be necessary in the design of actions to contrast and adapt to climate change, particularly in coastal areas.

scholarly journals INVESTIGASI PENGARUH KONDISI LALU LINTAS DAN ASPEK METEOROLOGI TERHADAP KONSENTRASI PENCEMAR SO2 DI KOTA SEMARANG

2016 ◽  
Vol 13 (1) ◽  
pp. 21
Author(s):  
Titik Istirokhatun ◽  
Ita Tetriana Agustini ◽  
Sudarno Sudarno
Keyword(s):  
Air Pollution ◽  
Sulfur Dioxide ◽  
Human Health ◽  
Adverse Reactions ◽  
Meteorological Factors ◽  
Ambient Air ◽  
Health Problems ◽  
Traffic Light ◽  
Road Users ◽  
The Impact

The  presence  of  air  pollution  in  ambient  air  is  closely  related  to  the incidence  of  adverse reactions affecting human health. One of harmful pollutants and potentially major cause health problems is sulfur dioxide (SO 2 ). The number of vehicles that are passing and queuing on the crossroads  because  of  traffic light can  affect  the  concentration  of  SO 2 .  Besides,  in  these locations  there  are a lot of road users  which  are  potentially  exposed  by  contaminants, so information about the concentration of SO 2  is important to know. This study aimed to investigate the  impact  of  meteorological  factors  and  the  number  of vehicles  on  SO 2   concentrations. Impinger was used for air sampling, and pararosaniline method was used for determining SO 2  concentration. Sampling and calculation  of the number of passing vehicles were performed 3 times ie in the morning, afternoon and evening. Based on the results of the study, the highest concentrations of SO 2  were on the range of 15-21 mg/Nm3.

THE EFFECT OF GROUNDWATER ON SOIL FORMATION IN A MORAINAL LANDSCAPE IN SASKATCHEWAN

1985 ◽  
Vol 65 (2) ◽  
pp. 293-307 ◽  
Author(s):  
J. J. MILLER ◽  
D. F. ACTON ◽  
R. J. ST. ARNAUD
Keyword(s):  
Groundwater Flow ◽  
Water Table ◽  
Soil Formation ◽  
Lateral Flow ◽  
Dominant Factor ◽  
Slope Position ◽  
Soluble Salts ◽  
Runoff Water ◽  
Depth To Water Table ◽  
Water Tables

The results of this study indicate the importance of groundwater flow and water table depth on the genesis, characteristics and distribution of soils within a hummocky morainal landscape. Non-saline and non-carbonated soils in upland depressions can be attributed to "depression-focused" recharge by snowmelt and snowmelt runoff in the spring, as evidenced by deep sola and/or eluvial horizons. Non-saline and carbonated soils on lower slopes adjacent to depressions are associated with local discharge and/or lateral flow from the adjacent groundwater mounds under the depressions in spring, as well as upward flow in the summer resulting from water use by phreatophytes such as willows, creating a water table depression around the slough fringes. Saline and carbonated soils at low elevations are associated with shallow and rather stable water tables, and local discharge from surrounding uplands. Soil types on uplands are more dependent on slope position and infiltration than on depth to water table or groundwater flow. Non-saline soils of different profile types occur on mid- and upper slope positions. These areas have a deep water table with mainly recharge or lateral flow occurring in the saturated zone. The infiltration of surface runoff water in upland depressions is the dominant factor influencing the distribution of soluble salts in this hummocky landscape. Key words: Water table, landscape position, recharge, discharge, soluble salts, soil genesis, morphology, carbonate soil

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