Controls on coastal overwash morphology in natural and built environments

2020 ◽  
Author(s):  
Hannah Williams ◽  
Luke Taylor ◽  
Evan Goldstein ◽  
Eli Lazarus
Keyword(s):  
Vegetation Coverage ◽  
Storm Event ◽  
Built Environments ◽  
Analogue Model ◽  
Sedimentary Deposits ◽  
Scaling Relationships ◽  
Exogenous Forcing ◽  
Set Up ◽  
Natural Settings ◽  
Experimental Basin

<p>Overwash is a key mechanism controlling the flux of sediment from the front of a barrier island to the top and back of an island during a storm event. The process is essential for barrier environments to maintain their height and width relative to sea level. Barrier topography and vegetation – and also road networks and buildings – can direct overwash flow, and thus the shape and size of sedimentary deposits that overwash leaves behind. Controls on overwash deposition have been examined more closely in natural settings than in developed zones. But overwash poses a major hazard to coastal infrastructure, and accurate prediction of storm impacts requires quantitative insight into the dynamics of overwash morphology in built settings. Here, we compare barrier floodplain controls across a range of spatial "fabrics", both natural and built (e.g., sparse to dense vegetation coverage; sparse to dense configurations of roads and buildings), to explore how these fabrics affect scaling relationships for overwash morphology. Integrating empirical measurements from post-storm imagery, trials of an analogue model in a small experimental basin, and results from a numerical toy model, we identify thresholds at which floodplain fabrics cause scaling relationships to change, or "break". Our findings illustrate a continuum in overwash pattern formation between endogenous self-organisation and exogenous forcing templates, and set up further inquiry into the dynamics of flood deposition in built environments.</p>

Temperature and conductivity as control parameters for pollution-based real-time control

2006 ◽  
Vol 54 (11-12) ◽  
pp. 257-263 ◽  
Author(s):  
R.P.S. Schilperoort ◽  
G. Gruber ◽  
C.M.L. Flamink ◽  
F.H.L.R. Clemens ◽  
J.H.J.M. van der Graaf
Keyword(s):  
Real Time ◽  
Monitoring Network ◽  
Storm Event ◽  
Real Time Control ◽  
Normal Behaviour ◽  
Time Control ◽  
Wastewater Systems ◽  
Typical Behaviour ◽  
Good Relation ◽  
Set Up

Most sewer system performance indicators are not easily measurable online at high frequencies in wastewater systems, which hampers real-time control with those parameters. Instead of using a constituent of wastewater, an alternative could be to use characteristics of wastewater that are relatively easily measurable in sewer systems and could serve as indicator parameters for the dilution process of wastewater. This paper focuses on the possibility to use the parameters of temperature and conductivity. It shows a good relation of temperature and conductivity with the dilution of DWF (dry weather flow) during WWF (wet weather flow) a monitoring station in Graz, Austria, as an example. The simultaneous monitoring of both parameters leads to valuable back-up information in case one parameter (temperature) shows no reaction to a storm event. However, for various reasons, anomalies occur in the typical behaviour of both parameters. The frequency and extent of these anomalies will determine the usefulness of the proposed parameters in a system for pollution-based real-time control. Both the normal behaviour and the anomalies will be studied further by means of trend and correlation analyses of data to be obtained from a monitoring network for the parameters of interest that is currently being set up in the Netherlands.

How grass contributes to controlling hillslope erosion

2020 ◽  
Author(s):  
Chengzhong Pan ◽  
Lan Ma
Keyword(s):  
Spatial Distribution ◽  
Soil Erosion ◽  
High Efficiency ◽  
Northern China ◽  
Bare Soil ◽  
Soil Characteristics ◽  
Vegetation Coverage ◽  
Grass Cover ◽  
Run Off ◽  
Set Up

<p>The aim of this study was to investigate how the spatial distribution of grass influenced run-off and erosion from a hillslope with loess and cinnamon soils in the rocky area of Northern China. We set up a trial to test the two soils with different treatments, including bare soil (BS), grass strips on the upper (UGS) and lower (DGS) parts of the slope, grass cover over the entire slope (GS), and a grass carpet on the lower part of the slope (GC), under simulated rainfall conditions. The results showed that the run-off coefficients for the loess and cinnamon soils decreased by between 4% and 20% and by between 2% and 37%, respectively, when covered with grass. Grass spatial distribution had little effect on the run-off, but more effect on erosion than vegetation coverage degree. The most effective location of grass cover for decreasing hillslope erosion was at the foot, and the high efficiency was mainly due to controlling of rill formation and sediment deposition. The soil loss from GS, DGS, and GC on the loess and cinnamon soils was between 77% and 93% less and 55% and 80% less, respectively, compared with the loss from BS. However, the soil characteristics had little effect on soil erosion for well-vegetated slopes. The results highlight the importance of vegetation re-establishment at the foot of hillslope in controlling soil erosion.</p>

Remote sensing of rainfall by satellite as an aid to Oedaleus senegalensis (Orthoptera: Acrididae) control in the Sahel

1995 ◽  
Vol 85 (4) ◽  
pp. 455-462 ◽  
Author(s):  
P.J.A. Burt ◽  
J. Colvin ◽  
S.M. Smith
Keyword(s):  
Rain Gauge ◽  
West African ◽  
Storm Event ◽  
Infra Red ◽  
Cloud Temperature ◽  
Set Up ◽  
West African Sahel ◽  
The Relationship ◽  
Oedaleus Senegalensis ◽  
African Sahel

AbstractThe Senegalese grasshopper, Oedaleus senegalensis (Krauss) (Orthoptera: Acrididae), is a major grasshopper pest of subsistence crops in the West African Sahel. In northern Mali, O. senegalensis spends the dry season in the egg stage in the soil and eclosion is triggered by the first rains which usually occur in May and June. Satellite imagery potentially enables rainfall, and hense O. senegalensis eclosion, to be monitored over much wider areas than those possible for ground-based observers. In 1990 and 1991, rain-gauge networks were set up at Mourdiah, northern Mali, and for each storm event, rainfall and Meteosat infra-red data were collected. The coldest convection clouds (< -70°C) produced rain 93.1% (n = 15) of the time, whereas warmer cloud (>- 10°C) produced rain only once (n = 61). The relationship between minimum cloud temperature and log transformed rainfall data was negative and highly significant (P < 0.0005). The maximum rain-gauge separation for reliable point measurements of rainfall was 8 km. Simulated rainfall experiments showed that O. senegalensis eclosion is influenced both by soil type and by the quantity of water added to the soil. A grasshopper survey after the first rain in 1994 showed that 8 mm of rain was sufficient to cause eclosion 9 days later. The implications of these results for improved O. senegalensis control are discussed.

scholarly journals Research on wave set-up during storms along the coast of Cua Dai, Hoi An

2019 ◽  
Vol 19 (3) ◽  
pp. 337-347
Author(s):  
Nguyen Nguyen Ngoc The The ◽  
Duong Cong Dien ◽  
Tran Thanh Tung
Keyword(s):  
Water Level ◽  
Research Output ◽  
Storm Surges ◽  
Data Series ◽  
Storm Event ◽  
Level Data ◽  
Study Results ◽  
Planning Development ◽  
Coast Of Vietnam ◽  
Set Up

The central coast of Vietnam is frequently prone to storms and floods. Aside from wind damages during storms, the effect of storm surges, which includes wave set-up, on the coast and coastal infrastructures is very severe. Therefore calculation and prediction of wave set-up and storm surges are significant, both scientifically and practically, to serve as scientific bases for sustainable coastal planning, development and protection. This paper presents the study results on nearshore wave propagation and transformation, as well as the distribution of wave set-up during storms in the coastal area of Cua Dai, Hoi An, using SWAN and SWASH models. The models are thoroughly tested against wave and water level data series collected during a campaign in the project framework. The simulation results show the overall picture of the nearshore wave field and the surge height induced by waves during a storm event along Cua Dai, Hoi An coast. The research output also indicates that wave set-up contributes an important part to the extreme water level of the local nearshore area during storms.

scholarly journals Effects of Tillage Methods and Vegetation Coverage on Reducing Runoff and Soil Erosion

2020 ◽  
Vol 194 ◽  
pp. 04039
Author(s):  
Ma Changchen ◽  
Wang Ran ◽  
Li Qingyuan ◽  
Lu Fangchun
Keyword(s):  
Soil Erosion ◽  
Soil Loss ◽  
Vegetation Coverage ◽  
Annual Rainfall ◽  
Monthly Precipitation ◽  
Positive Correlation ◽  
Runoff Depth ◽  
Set Up ◽  
Tillage Methods ◽  
Runoff Plot

To study the characteristics of runoff and soil erosion of natural rainfall conditions, five standard runoff plots were set up in our experiment, and different tillage methods and vegetation coverage types were set up. The 58-month monthly precipitation data and 44-month runoff plot observation data from 2013 to 2017 were analysed. The results show that: 1) The monthly precipitation fluctuates significantly, ranging from 13mm to 683.5mm. The precipitation is unevenly distributed over the year. The largest average monthly precipitation is in June and the smallest is in January. Rainfall is mainly concentrated in the spring and summer. The precipitation from March to June accounts for 58.0% of the annual rainfall. 2) There is a positive correlation between runoff depth and precipitation in each runoff plot (R2= 0. 5101~0. 6676, Sig.<0.01); 3) There is also a positive correlation between soil loss and precipitation (R2=0. 424~0. 558, Sig.<0.01); 4) The amount of soil loss and the runoff depth increase with increasing rainfall. The runoff plot without any vegetation cover or farming measures increase the most. While the one with horizontal steps and shrubs, or a combination of arbor and grass increase the slowest, indicating that they have the best effect of reducing runoff and soil loss.

scholarly journals Are the new mobile wireless EEG headsets reliable for the evaluation of musical pleasure?

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244820
Author(s):  
Thibault Chabin ◽  
Damien Gabriel ◽  
Emmanuel Haffen ◽  
Thierry Moulin ◽  
Lionel Pazart
Keyword(s):  
Gold Standard ◽  
Large Scale ◽  
Rapid Development ◽  
High Price ◽  
Wireless Devices ◽  
Medical Needs ◽  
Set Up ◽  
Natural Settings ◽  
Musical Emotion ◽  
Wireless Eeg

Since the beginning of the 20th century, electroencephalography (EEG) has been used in a wide variety of applications, both for medical needs and for the study of various cerebral processes. With the rapid development of the technique, more and more precise and advanced tools have emerged for research purposes. However, the main constraints of these devices have often been the high price and, for some devices the low transportability and the long set-up time. Nevertheless, a broad range of wireless EEG devices have emerged on the market without these constraints, but with a lower signal quality. The development of EEG recording on multiple participants simultaneously, and new technological solutions provides further possibilities to understand the cerebral emotional dynamics of a group. A great number of studies have compared and tested many mobile devices, but have provided contradictory results. It is therefore important to test the reliability of specific wireless devices in a specific research context before developing a large-scale study. The aim of this study was to assess the reliability of two wireless devices (g.tech Nautilus SAHARA electrodes and Emotiv™ Epoc +) for the detection of musical emotions, in comparison with a gold standard EEG device. Sixteen participants reported feeling emotional pleasure (from low pleasure up to musical chills) when listening to their favorite chill-inducing musical excerpts. In terms of emotion detection, our results show statistically significant concordance between Epoc + and the gold standard device in the left prefrontal and left temporal areas in the alpha frequency band. We validated the use of the Emotiv™ Epoc + for research into musical emotion. We did not find any significant concordance between g.tech and the gold standard. This suggests that Emotiv Epoc is more appropriate for musical emotion investigations in natural settings.

scholarly journals MOVABLE BED MODEL TESTS ON DUNE EROSION

1978 ◽  
Vol 1 (16) ◽  
pp. 122
Author(s):  
P. Vellinga
Keyword(s):  
Sandy Beaches ◽  
Design Criterion ◽  
Dune Erosion ◽  
Scaling Relationships ◽  
Defence System ◽  
Guide Line ◽  
Set Up ◽  
Hydraulics Laboratory ◽  
Movable Bed

The primary sea defence system of the Netherlands consists for a large part of sandy beaches and dunes. The row of dunes, however, is rather narrow in some places, due to long-term erosion, and reinforcement has become necessary (Figure 1 and 2). In this connection a special governmental committee requested the co-operation of the Delft Hydraulics Laboratory to developed a design criterion for a dune sea defence system that could withstand a storm surge with a frequency of occurrence of once in 10,000 years (Figure 3). For that purpose all available field observations on dune erosion were analysed and a provisional, empirical, guide-line was developed in 1972 \_\J , but because of the limited amount of field data and the complexity of a theoretical approach it was decided to check the validity of this guide-line by means of a model investigation. As no adequate scaling relationships are available for movable bed models with waves, the tests were set up in the form of a scale series. A large number of two-dimensional tests with various geometric scales using two types of sand (D50 = 225 um and D50 = 150 urn) was carried out in 1975.

scholarly journals Microbiome dynamics during the HI-SEAS IV mission, and implications for future crewed missions beyond Earth

2020 ◽  
Author(s):  
Alexander Mahnert ◽  
Cyprien Verseux ◽  
Petra Schwendner ◽  
Kaisa Koskinen ◽  
Christina Kumpitsch ◽  
...  
Keyword(s):  
Built Environment ◽  
Microbial Diversity ◽  
Rrna Gene ◽  
Built Environments ◽  
Microbial Monitoring ◽  
Future Space ◽  
Microbiome Diversity ◽  
Set Up ◽  
One Year

Abstract BackgroundHuman health is closely interconnected with its microbiome. Stable microbiomes in, on and around the human body will be key for safe and successful long-term space travel. However, longitudinal dynamics of microbiomes inside confined built environments are still poorly understood. Herein we used the Hawaii Space Exploration Analog and Simulation IV (HI-SEAS IV) mission, a one year-long isolation study, to investigate microbial transfer between crew and habitat, in order to understand adverse developments which might occur in an outpost on the Moon or Mars in the future.ResultsLongitudinal profiles of the 16S rRNA gene revealed significant differences in microbial diversity and composition between samples of the built environment and its crew. While microbial profiles from individual crew members were highly dynamic, the microbiome on built environment surfaces remained more stable. Especially within the first 200 days, archaeal signatures of Methanobrevibacter were regularly transferred between crew members, but did not impact the microbiome on habitat surfaces. In contrast to a rather stable microbial diversity recovered from surfaces of the habitat, microbial diversity from the crew’s skin increased over time. Quantitative observations based on qPCR supported observations of dissimilarity between the built environment and its crew and was also used to track the propagation of antimicrobial resistances in the habitat. Together with functional and phenotypic predictions, quantitative and qualitative data both supported the observation of a delayed longitudinal homogenization between the crew and their habitat, that was mainly caused by the hygiene infrastructure.ConclusionsThe study highlights main routes of microbial transfer, interaction of its crew and origins of microbial dynamics in an isolated set-up. We identified key targets of microbial monitoring, and emphasize the need for defined baselines of microbiome diversity and abundance on surfaces and skin. Targeted manipulation to counteract adverse developments of the microbiome will be a highly important strategy to ensure safety during future space endeavors.

Optimization of the rehabilitation of the Emscher drainage system using continuous rainfall-runoff-modeling

1997 ◽  
Vol 36 (8-9) ◽  
pp. 33-37
Author(s):  
E. Pfeiffer ◽  
M. Simon
Keyword(s):  
Water Resources ◽  
Flood Control ◽  
Anthropogenic Impacts ◽  
Control Strategies ◽  
Drainage System ◽  
Storm Event ◽  
Rainfall Runoff ◽  
Actual System ◽  
Rainfall Runoff Model ◽  
Set Up

The northbound migration of maining activities in the Emscher Region is making the open combined sewer system obsolete. This complex task requires a large number of water resources development activities in the subcatchments of tributaries. To harmonize these single activities and to evaluate their performance as part of the complete system a detailed rainfall-runoff-model of the whole Emscher system has been set up. Intensive anthropogenic impacts made it necessary to use actual system data to run advanced modeling techniques. The model set-up and first applications have been recently completed. The reconstruction of the extreme storm event of January 1995 showed excellent results. One of the major objectives is the reduction of flood levels by decentral retention measures. An evaluation matrix will be set up for the 22 potential sites for flood storage with a total volume of 4.8 million m3. Reconstruction plans developed through interdisciplinary investigations will be ranked concerning potential for realization and water resources benefits. In the mean and long range the applicability of approaches for flood control strategies using real-time forecasting models will be checked.

scholarly journals Study on the effects of wave-induced setup on coastal evolution of the Cua Dai beach, Hoi An

2021 ◽  
Vol 21 (3) ◽  
pp. 247-257
Author(s):  
Ngoc The Nguyen ◽  
Thanh Tung Tran ◽  
Trung Viet Nguyen
Keyword(s):  
Coastal Dunes ◽  
Weather Conditions ◽  
Beach Erosion ◽  
Storm Event ◽  
Coastal Evolution ◽  
Level Data ◽  
Water Level Data ◽  
Set Up ◽  
Wave Induced ◽  
Hydrodynamic Factors

Over the past years, there have been several studies on the hydrodynamic regime, beach erosion, and accretion at the Cua Dai beach in Hoi An city. However, there is still a lack of in-depth research on the effects of hydrodynamic factors on beach evolution in extreme weather conditions such as a storm event or during the Northeast monsoons, characterized by large waves mainly, especially. The wave set-up directly impacts on the evolution of upper beaches and coastal dunes, consequently causing beach erosion. This paper presents the results of nearshore wave propagation and transformation and the distribution of wave set-up during storms in the coastal area of Cua Dai, Hoi An, using the SWAN model and the XBEACH model. The models have been calibrated and validated using measured wave and water level data observed in the study area in October 2016. The simulation results have shown the overall picture of the influence of wave set-up on the morphology evolution of beach profiles in the study area.

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