scholarly journals Assessing the capabilities of the SWOT mission for large lake water surface elevation monitoring under different wind conditions

2020 ◽  
Author(s):  
Jean Bergeron ◽  
Gabriela Siles ◽  
Robert Leconte ◽  
Mélanie Trudel ◽  
Damien Desroches ◽  
...  
Keyword(s):  
Water Surface ◽  
Management Strategies ◽  
Water Volume ◽  
Spatial And Temporal Variability ◽  
Large Lakes ◽  
Spatial Coverage ◽  
Lake Hydrodynamics ◽  
Ocean Topography ◽  
Set Up ◽  
Net Flows

Abstract. Lakes are important sources of freshwater and provide essential ecosystem services. Monitoring their spatial and temporal variability, as well as of their functions, is an important task within the development of sustainable water management strategies. The Surface Water and Ocean Topography (SWOT) mission will provide continuous information on the dynamics of continental (rivers, lakes, wetlands and reservoirs) and ocean water bodies. This work aims to contribute to the international effort evaluating the SWOT satellite (2022 launch) performance for water balance assessment over large lakes (e.g., > 100 km2). For this purpose, a hydrodynamic model was set up over Mamawi Lake, Canada, and different wind scenarios on lake hydrodynamics were simulated. The derived water surface elevations (WSE) were compared to synthetic elevations produced by the Jet Propulsion Laboratory (JPL) SWOT high resolution (SWOT-HR) simulator. Moreover, water storages and net flows were retrieved from different possible SWOT orbital configurations, as well as synthetic gauge measurements. In general, a good agreement was found between the WSE simulated from the model and those mimicked by the SWOT-HR simulator. Depending on the wind scenario, errors ranged between approximately −2 and 5 cm for mean error, and 30 to 70 cm root mean square error. Low spatial coverage of the lake was found to generate important biases in the retrievals of water volume or net flow between two satellite passes in the presence of local heterogeneities in WSE. However, the precision of retrievals was found to increase as spatial coverage increases, becoming more reliable than the retrievals from 3 synthetic gauges when spatial coverage approaches 100 %, demonstrating the capabilities of the future SWOT mission in monitoring dynamic WSE for large lakes across Canada.

scholarly journals Assessing the capabilities of the Surface Water and Ocean Topography (SWOT) mission for large lake water surface elevation monitoring under different wind conditions

2020 ◽  
Vol 24 (12) ◽  
pp. 5985-6000
Author(s):  
Jean Bergeron ◽  
Gabriela Siles ◽  
Robert Leconte ◽  
Mélanie Trudel ◽  
Damien Desroches ◽  
...  
Keyword(s):  
Surface Water ◽  
Water Surface ◽  
Management Strategies ◽  
Water Volume ◽  
Spatial And Temporal Variability ◽  
Large Lakes ◽  
Spatial Coverage ◽  
Lake Hydrodynamics ◽  
Ocean Topography ◽  
Set Up

Abstract. Lakes are important sources of freshwater and provide essential ecosystem services. Monitoring their spatial and temporal variability, and their functions, is an important task within the development of sustainable water management strategies. The Surface Water and Ocean Topography (SWOT) mission will provide continuous information on the dynamics of continental (rivers, lakes, wetlands and reservoirs) and ocean water bodies. This work aims to contribute to the international effort evaluating the SWOT satellite (2022 launch) performance for water balance assessment over large lakes (e.g., >100 km2). For this purpose, a hydrodynamic model was set up over Mamawi Lake, Canada, and different wind scenarios on lake hydrodynamics were simulated. The derived water surface elevations (WSEs) were compared to synthetic elevations produced by the Jet Propulsion Laboratory (JPL) SWOT high resolution (SWOT-HR) simulator. Moreover, water storages and net flows were retrieved from different possible SWOT orbital configurations and synthetic gauge measurements. In general, a good agreement was found between the WSE simulated from the model and those mimicked by the SWOT-HR simulator. Depending on the wind scenario, errors ranged between approximately −2 and 5 cm for mean error and from 30 to 70 cm root mean square error. Low spatial coverage of the lake was found to generate important biases in the retrievals of water volume or net flow between two satellite passes in the presence of local heterogeneities in WSE. However, the precision of retrievals was found to increase as spatial coverage increases, becoming more reliable than the retrievals from three synthetic gauges when spatial coverage approaches 100 %, demonstrating the capabilities of the future SWOT mission in monitoring dynamic WSE for large lakes across Canada.

Seagrass characterization on the southern Pacific coast of Costa Rica: history, vegetation, and environment

2020 ◽  
Vol 63 (5) ◽  
pp. 429-438
Author(s):  
Jimena Samper-Villarreal ◽  
Jorge Cortés
Keyword(s):  
Costa Rica ◽  
Pacific Coast ◽  
Management Strategies ◽  
Shoot Density ◽  
Nutrient Concentrations ◽  
Seagrass Habitat ◽  
Spatial And Temporal Variability ◽  
Seagrass Species ◽  
Seagrass Biomass ◽  
Herbarium Collections

AbstractSeagrass conservation and management requires scientific understanding of spatial and temporal variability, information that is currently limited for the Eastern Tropical Pacific (ETP). Here, we analysed seagrass presence based on previous reports, herbarium collections and stakeholder knowledge, combined with field characterization in Golfo Dulce, southern Pacific coast of Costa Rica. Seagrasses were found at multiple locations along a narrow border close to shore and in up to 6 m depth within Golfo Dulce, dating back to 1969. Two seagrass species were found, Halophila baillonii and Halodule beaudettei. Seagrass biomass values for Golfo Dulce (12.0 ± 8.5 g DW m−2) were lower and water nutrient concentrations were higher than previously reported in the gulf. Shoot density (1513 ± 767 shoots m−2) was similar to previous reports. Stable isotope values in seagrass were −11.3 ± 1.0‰ δ13C and 1.2 ± 0.9‰ δ15N; while those in sediments were −26.1 ± 1.3 and 2.5 ± 0.9‰. In Golfo Dulce, isotopic values of both seagrass species do not overlap with other known primary producers. Management strategies should aim to minimize known seagrass stressors, protect potential seagrass habitat, and take into account the dynamic life strategies of the two seagrass species found.

The Tahaddart estuary, NW of Morocco: evidence of marine submersion events during the last 3500 years 

2021 ◽  
Author(s):  
Otmane Khalfaoui ◽  
laurent Dezileau ◽  
Jean-Philippe Degeai ◽  
Maria Snoussi
Keyword(s):  
Late Holocene ◽  
Atlantic Coast ◽  
High Energy ◽  
Mitigation Strategies ◽  
Spatial And Temporal Variability ◽  
Progressive Change ◽  
Marine Facies ◽  
Set Up ◽  
Long Term Studies

<p>The Atlantic coast of Morocco has been confronted with several marine submersion events. Historically, some of them have resulted in significant economic and human damage, including the 1755 AD event (known as the tsunami of Lisbon). This indicates the need to implement adaptation and mitigation strategies, based on long-term studies of these extreme events to deduce their spatial and temporal variability. Using two cores (TAH17-1 and TAH17-3) collected from the Tahaddart estuary (NW of Morocco), this work aims to identify deposits, set up by these high energy events during the mid to late Holocene period. The sedimentological, geochemical and geochronological analyses carried out on these geological archives show two fining-upward sequences, indicating a progressive change from a purely sandy marine facies, between 6500 and 3500 BP, to another finer and more terrigenous one. The fine sedimentation, which has dominated in the estuary during the last 3500 years, has facilitated the recording of several marine submersion events in the form of isolated sandy layers. Chronological data have made it possible to date four deposits. Two (1-E1 and 3-E1) were put in place about 250 years ago, which corresponds, according to historical records, to the 1755 AD Lisbon tsunami. Two other deposits (1-E13 and 1-E14) are dated around 3200 BP and represent unknown submersion events on the Moroccan Atlantic coast.</p>

scholarly journals Low Genetic Connectivity of Strongly Inbred Ruppia brevipedunculata in Aquaculture Dominated Lagoons (Viet Nam)

2021 ◽  
Vol 2 ◽  
Author(s):  
Ludwig Triest ◽  
Jasper Dierick ◽  
Thi Thuy Hang Phan ◽  
Quang Doc Luong ◽  
Nguyen Quang Huy ◽  
...  
Keyword(s):  
Water Surface ◽  
Ecological Factors ◽  
Survival Strategies ◽  
Genetic Connectivity ◽  
Spatial And Temporal Variability ◽  
Gene Pools ◽  
Aquaculture Ponds ◽  
Genetic Differentiation Of Populations ◽  
The Many ◽  
Private Alleles

Lagoonal environments exhibit high levels of instability depending on hydrological, climatic and ecological factors, thereby influencing the distribution and structure of submerged plant communities. Conditions typically fluctuate widely due to the interaction of freshwater from rivers with saltwater from the sea, as well as from aquaculture activities that together influence submerged hydrophyte community spatial and temporal variability depending on plant survival strategies. Ruppia species feature either underwater pollination mediated by an air bubble or by the release of pollen floating at the water surface, the former promoting self-pollination. Tropical Asian Ruppia brevipedunculata Yu and den Hartog was assumed to pollinate below the water surface and identified as a separate lineage among selfed Ruppia taxa. We used nine nuclear microsatellites to estimate inbreeding levels and connectivity of R. brevipedunculata within a large SE Asian lagoon complex. Ruppia brevipedunculata meadows were strongly inbred as could be derived from the many monomorphic or totally fixed loci for unique alleles in different parts of the lagoon, which appears consistent with selfing behavior. Those from aquaculture ponds were highly inbred (FIS = 0.620), though less than open lagoon sites that showed nearly total inbreeding (FIS = 0.942). Ruppia brevipedunculata from two major lagoon parts were highly differentiated with spatially structured gene pools and a strong barrier between parts of the lagoon over a 30 km distance. Migration-n analysis indicated unidirectional though limited gene flow and following potential hydrological connectivity. Overall, private alleles under homozygote conditions explained a stronger genetic differentiation of populations situated inside aquaculture ponds than of open lagoon populations. Kinship values were only relevant up to 5 km distance in the open lagoon. Within a confined area of aquaculture ponds featuring dense vegetation in stagnant water, there would be opportunity for mixed pollination, thereby explaining the higher diversity of unique multilocus genotypes of aquaculture pond habitats. Low connectivity prevents gene pools to homogenize however promoted sites with private alleles across the lagoon. Complex hydrodynamic systems and human-made habitats enclosed by physical structures impose barriers for propagule dispersal though may create refugia and contribute to conserving regional genetic diversity.

scholarly journals Surface Heat Budget estimation for Laurance Lake, US

2021 ◽  
Vol 877 (1) ◽  
pp. 012005
Author(s):  
Dahlia S. Abed-Zaid ◽  
Hussein A. M. Al-Zubaidi
Keyword(s):  
Surface Temperature ◽  
Water Surface ◽  
Heat Budget ◽  
Meteorological Data ◽  
Longwave Radiation ◽  
Atmospheric Conditions ◽  
Large Lakes ◽  
Water Surface Temperature ◽  
Maximum Water ◽  
The Many

Abstract Estimating heat budget factors are important to understand the many physical processes of large lakes and their reaction to the atmosphere. Some of these components are affected by water temperature, while the other depends on atmospheric conditions. This paper estimates the total heat flux for Lawrence lake via a code developed in MATLAB environment. The code can deal with different time resolutions if the lake water surface temperature data were at different time resolutions from the meteorological data. Results showed that solar energy peaks at 842 Watt/m2 at 540 Julian day, which is very normal for a sunny summer day, while the longwave radiation has 204 Watt/m2 as a min value. The back radiation did not make any reaction for the variation, but it revealed a small gradient. Furthermore, evaporation recorded - 67 Watt/m2 as a minimum value at 659 Julian day and 360 Watt/m2 as a maximum value at 578.43 Julian day close to the maximum water surface temperature event.

scholarly journals Comparison among Different Rewetting Strategies of Degraded Agricultural Peaty Soils: Short-Term Effects on Chemical Properties and Ecoenzymatic Activities

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1084
Author(s):  
Vittoria Giannini ◽  
Eleonora Peruzzi ◽  
Grazia Masciandaro ◽  
Serena Doni ◽  
Cristina Macci ◽  
...  
Keyword(s):  
Peat Soil ◽  
Management Strategies ◽  
Chemical Properties ◽  
Total Carbon ◽  
Available Phosphorus ◽  
Total Carbon Content ◽  
Peatland Restoration ◽  
Physico Chemical ◽  
Wetland System ◽  
Set Up

In 2013, a pilot experimental field of about 15 ha was set up within the basin of Lake Massaciuccoli (Tuscany, Italy) in order to compare different management strategies—a paludicultural system (PCS), a constructed wetland system (CWS), a nearly-natural wetland system (NWS)—for peatland restoration after almost a century of drainage-based agricultural use (CS). After five years, changes in peat soil quality were investigated from a chemical, biochemical, and ecoenzymatic perspective. The soil in CS was mainly characterized by oxidant conditions, higher content of overall microbial activity, low levels of easily available phosphorus for vegetation, and medium total carbon content ranging from 25.0% to 30.7%. In PCS, the levels of total carbon and the content of bioavailable P were higher, while the oxidant conditions were lower compared to the other systems. As expected, the soils in CWS and NWS were characterized by the most reduced conditions and by the highest levels of arylsulphatase activity. It was noteworthy that soils in the NWS systems were characterized by the highest level of nonavailable P. Outputs from ecoenzymatic activity confirmed the physico-chemical and biochemical results.

scholarly journals Analysis of repeat LSCS in a tertiary care centre

2018 ◽  
Vol 7 (5) ◽  
pp. 1963
Author(s):  
M. Poovathi ◽  
Suilharsini T. S.
Keyword(s):  
Caesarean Section ◽  
Tamil Nadu ◽  
Caesarean Section Rate ◽  
Tertiary Care ◽  
Management Strategies ◽  
Negative Consequences ◽  
Care Needs ◽  
Tertiary Care Centre ◽  
Medical College ◽  
Set Up

Background: Caesarean section (CS) rates continue to increase worldwide, particularly in middle and high-income countries without evidence indicating substantial maternal and perinatal benefits from the increase and some studies showing negative consequences for maternal and neonatal health. The objective of this study is to analyse the repeat caesarean section rates in a tertiary centre.Methods: This is a retrospective study carried out in the Department of Obstetrics and Gynaecology, Pudhukottai Medical College, Tamil Nadu, India for a 12-month period from January 2017 to December 2017 with the aim to analyse the rate and indications for caesarean section and to identify the measures to decrease its incidence if possible. A total of 2654 cesarean deliveries were conducted in one year, out of which 1380 (51.99%) were primary cesarean sections and 1274(48%) were repeat cesarean sections.Results: Repeat LSCS is more common in age group of 21-30 years (80%) and in second gravida (90.42%). The incidence of caesarean section is 94.6%. Patients who had successful trial of scar were 73. In all these patients, measures were taken to shorten the 2nd stage of labour either by giving episiotomy alone or by application of outlet forceps or vacuum. Out of these 62 (84.9%) patients were delivered by episiotomy alone.Conclusions: Caesarean section has become one of the commonly performed surgeries in obstetric practice. Implementation of standard labour management strategies can reduce primary caesarean section rate without compromising maternal and fetal safety. One important strategy is ROBSON ‘S 10 GROUP classification system for caesarean section needs to be adopted. Targets of care needs to be set up which also depends on the available resources and expertise. With continuous critical review as described and frequent comparison with other delivery units, the caesarean section rate in each individual unit can be reduced to an appropriate level.

scholarly journals Contributing Factors, Prevention, and Management of Playing-Related Musculoskeletal Disorders Among Flute Players Internationally

2014 ◽  
Vol 29 (3) ◽  
pp. 155-162 ◽  
Author(s):  
Karen Lonsdale ◽  
E-Liisa Laakso ◽  
Vanessa Tomlinson
Keyword(s):  
Longitudinal Study ◽  
Teaching Methods ◽  
Management Strategies ◽  
Extended Period ◽  
Education History ◽  
Contributing Factors ◽  
Current Survey ◽  
History Of ◽  
Set Up ◽  
The Relationship

Major studies have shown that flutists report playing-related pain in the neck, middle/upper back, shoulders, wrists, and hands. The current survey was designed to establish the injury concerns of flute players and teachers of all backgrounds, as well as their knowledge and awareness of injury prevention and management. Questions addressed a range of issues including education, history of injuries, preventative and management strategies, lifestyle factors, and teaching methods. At the time of the survey, 26.7% of all respondents were suffering from flute playing-related discomfort or pain; 49.7% had experienced flute playing-related discomfort or pain that was severe enough to distract while performing; and 25.8% had taken an extended period of time off playing because of discomfort or pain. Consistent with earlier studies, the most common pain sites were the fingers, hands, arms, neck, middle/upper back, and shoulders. Further research is needed to establish possible links between sex, instrument types, and ergonomic set up. Further investigation is recommended to ascertain whether certain types of physical training, education, and practice approaches may be more suitable than current methods. A longitudinal study researching the relationship between early education, playing position, ergonomic set-up, and prevalence of injury is recommended.

scholarly journals Wind-induced Stresses on Water Surfaces: A Wind-tunnel Study

1963 ◽  
Vol 16 (4) ◽  
pp. 475 ◽  
Author(s):  
LM Fitzgerald
Keyword(s):  
Wind Tunnel ◽  
Surface Stress ◽  
Water Surface ◽  
Surface Films ◽  
Surface Slope ◽  
Wind Speeds ◽  
Induced Stresses ◽  
Set Up ◽  
Wind Tunnel Study ◽  
Good Agreement

A laboratory wind tunnel has been used to study the effect of wind on a water surface. The surface shearing stress 7'0 and the slope of the surface induced by wind have been measured. Values of the surface stress, in good agreement with each other, have been obtained from: (a) the velocity profile of the wind above the water surface, (b) the measured values of surface slope or set-up, and (c) the spreading characteristics of surface films. The drag coefficient, Cn = TO/ pu2n, was found to be constant for wind speeds up to about 412 cm/s and then to rise gradually for higher wind speeds.

scholarly journals 10-year spatial and temporal trends of PM<sub>2.5</sub> concentrations in the southeastern US estimated using high-resolution satellite data

2014 ◽  
Vol 14 (12) ◽  
pp. 6301-6314 ◽  
Author(s):  
X. Hu ◽  
L. A. Waller ◽  
A. Lyapustin ◽  
Y. Wang ◽  
Y. Liu
Keyword(s):  
Spatial Resolution ◽  
Urban Areas ◽  
Prediction Error ◽  
Atmospheric Correction ◽  
Temporal Trends ◽  
Continuous Distribution ◽  
Spatial And Temporal Variability ◽  
Significant Drop ◽  
Southeastern Us ◽  
Spatial Coverage

Abstract. Long-term PM2.5 exposure has been associated with various adverse health outcomes. However, most ground monitors are located in urban areas, leading to a potentially biased representation of true regional PM2.5 levels. To facilitate epidemiological studies, accurate estimates of the spatiotemporally continuous distribution of PM2.5 concentrations are important. Satellite-retrieved aerosol optical depth (AOD) has been increasingly used for PM2.5 concentration estimation due to its comprehensive spatial coverage. Nevertheless, previous studies indicated that an inherent disadvantage of many AOD products is their coarse spatial resolution. For instance, the available spatial resolutions of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Multiangle Imaging SpectroRadiometer (MISR) AOD products are 10 and 17.6 km, respectively. In this paper, a new AOD product with 1 km spatial resolution retrieved by the multi-angle implementation of atmospheric correction (MAIAC) algorithm based on MODIS measurements was used. A two-stage model was developed to account for both spatial and temporal variability in the PM2.5–AOD relationship by incorporating the MAIAC AOD, meteorological fields, and land use variables as predictors. Our study area is in the southeastern US centered at the Atlanta metro area, and data from 2001 to 2010 were collected from various sources. The model was fitted annually, and we obtained model fitting R2 ranging from 0.71 to 0.85, mean prediction error (MPE) from 1.73 to 2.50 μg m−3, and root mean squared prediction error (RMSPE) from 2.75 to 4.10 μg m−3. In addition, we found cross-validation R2 ranging from 0.62 to 0.78, MPE from 2.00 to 3.01 μg m−3, and RMSPE from 3.12 to 5.00 μg m−3, indicating a good agreement between the estimated and observed values. Spatial trends showed that high PM2.5 levels occurred in urban areas and along major highways, while low concentrations appeared in rural or mountainous areas. Our time-series analysis showed that, for the 10-year study period, the PM2.5 levels in the southeastern US have decreased by ~20%. The annual decrease has been relatively steady from 2001 to 2007 and from 2008 to 2010 while a significant drop occurred between 2007 and 2008. An observed increase in PM2.5 levels in year 2005 is attributed to elevated sulfate concentrations in the study area in warm months of 2005.

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