scholarly journals SUSPENDED SEDIMENT DISCHARGE ON A NON-TIDAL COAST

1982 ◽  
Vol 1 (18) ◽  
pp. 79 ◽  
Author(s):  
J.P. Coakley ◽  
M.G. Skafel
Keyword(s):  
Field Study ◽  
Suspended Sediment ◽  
Wave Energy ◽  
Sediment Discharge ◽  
Sand Beach ◽  
Data Set ◽  
Longshore Transport ◽  
Suspended Sediment Concentrations ◽  
Tidal Sand ◽  
The Relationship

A field study was conducted on a non-tidal sand beach to measure the relationship between wave energy and the longshore transport of suspended sediment. The range of suspended sediment concentrations was similar to that reported elsewhere. The relation between longshore transport and longshore energy flux derived from this data set is about half that amount predicted by such widely quoted sources as Komar and Inman (1970).

scholarly journals Wavelet analysis for modeling suspended sediment discharge

2004 ◽  
Vol 35 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Hafzullah Aksoy ◽  
Tanju Akar ◽  
N. Erdem Ünal
Keyword(s):  
Suspended Sediment ◽  
Moving Average ◽  
Haar Wavelet ◽  
Finite Variance ◽  
Sediment Discharge ◽  
Average Process ◽  
Moving Average Process ◽  
Discharge Time ◽  
Data Set ◽  
Environmental Processes

Wavelets, functions with zero mean and finite variance, have recently been found to be appropriate tools in investigating geophysical, hydrological, meteorological, and environmental processes. In this study, a wavelet-based modeling technique is presented for suspended sediment discharge time series. The model generates synthetic series statistically similar to the observed data. In the model in which the Haar wavelet is used, the available data are decomposed into detail functions. By choosing randomly from among the detail functions, synthetic suspended sediment discharge series are composed. Results are compared with those obtained from a moving-average process fitted to the data set.

The effect of suspended sediment on fertilization success in sockeye (Oncorhynchus nerka) and coho (Oncorhynchus kisutch) salmon

2006 ◽  
Vol 63 (11) ◽  
pp. 2487-2494 ◽  
Author(s):  
Ryan V Galbraith ◽  
Erland A MacIsaac ◽  
J Stevenson Macdonald ◽  
Anthony P Farrell
Keyword(s):  
Suspended Sediment ◽  
Pacific Salmon ◽  
Oncorhynchus Nerka ◽  
Oncorhynchus Kisutch ◽  
Sediment Concentration ◽  
Fertilization Success ◽  
Suspended Sediment Concentrations ◽  
Controlled Flow ◽  
The Impact ◽  
The Relationship

Suspended sediment is a naturally occurring part of aquatic ecosystems, and unnatural elevation of suspended sediment in streams above background concentrations is known to adversely affect Pacific salmon (Oncorhynchus spp.) at different life stages. Conspicuously lacking in the literature is knowledge of the effect of suspended sediment on egg fertilization success during spawning. Sockeye (Oncorhynchus nerka) and coho (Oncorhynchus kisutch) salmon gametes were used to investigate the impact of different concentrations of suspended sediment particles on the ability of sperm to successfully fertilize eggs. The fertilization process was simulated using a controlled-flow water flume with concentrations of suspended particles ranging from 800 to 47 000 mg·L–1. Egg fertilization success was assessed at eyed stage after incubating eggs in the streambed in the field or in artificial laboratory egg incubation (Heath) trays. Regression model analysis showed that suspended sediment concentrations reduced the percent of fertilized eggs and that reduction in successful fertilization below 80% could occur when suspended sediment levels are in excess of 9000 mg·L–1. The relationship derived herein serves as a preliminary guideline for determining the effect size of suspended sediment concentration on egg fertilization success during spawning.

scholarly journals NEARSHORE SUSPENDED SEDIMENT LOAD DURING STORM AND POSXTSTORM CONDITIONS

1980 ◽  
Vol 1 (17) ◽  
pp. 70
Author(s):  
Timothy W. Kana ◽  
Larry G. Ward
Keyword(s):  
Suspended Sediment ◽  
Energy Flux ◽  
Wave Energy ◽  
Surf Zone ◽  
Field Research ◽  
Bulk Water ◽  
Total Load ◽  
Zone Width ◽  
Longshore Transport ◽  
Wave Energy Flux

As part of the DUCK-X experiment at the CERC field research facility at Duck, North Carolina in September, 1978, suspended sediment measurements were made along the CERC pier. In situ bulk water samples were collected during a moderate northeast storm and two days later during post-storm wave conditions. Concentrations varied from approximately 0.01 g/1 to over 10.0 g/1. Vertical arrays of suspended sediment samples indicated that concentration decreases rapidly up to two meters above the bed, then remains relatively constant, reflecting the nature of the suspension; intermittent suspension of sand near the bed, and continuous washload higher in the water column. Concentrations were at a maximum during storm conditions when measured values were 3 to 5 times higher than during non-storm conditions. The total load of sediment in a pier cross section during sampling periods in storm and post^storm conditions was calculated from arrays of 49 samples each. With H1/3 exceeding 2.3 HI and the surf zone width over 300 m during the storm, the total load of sediment in suspension was approximately 10 times higher than during poststorm conditions (Hi 73 - 1.2 m and surf zone width approximately 100 m) . Estimates of the longshore flux of suspended sediment indicate that as much as 60 times more sediment was transported during storm than during post-storm conditions. Longshore transport of sediment measured from 5 cm above the bed to the surface reached the equivalent of 22,330 m^/day. This value corresponds very closely to longshore transport predicted from wave energy flux. During post-storm conditions, on the other hand, transport of suspended sediment accounts for less than one-third of the transport predicted from wave energy flux.

scholarly journals Comparison of Acoustic to Optical Backscatter Continuous Measurements of Suspended Sediment Concentrations and Their Characterization in an Agriculturally Impacted River

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 981 ◽  
Author(s):  
Zacharie Sirabahenda ◽  
André St-Hilaire ◽  
Simon C. Courtenay ◽  
Michael R. van den Heuvel
Keyword(s):  
Suspended Sediment ◽  
Drainage Basin ◽  
Acoustic Doppler Current Profiler ◽  
Agricultural Watershed ◽  
Indirect Measurements ◽  
Sediment Budgets ◽  
Suspended Sediment Concentrations ◽  
Frequency Monitoring ◽  
Current Profiler ◽  
The Relationship

The increased soil loss in an agricultural watershed raises challengers for river water quality and a reliable automated monitoring for suspended sediment concentrations (SSC) is crucial to evaluate sediment budgets variation in systems. The aims of this study were (1) to test if an acoustic doppler current profiler (ADCP) would give similar results to turbidity probe measurements as a high frequency monitoring tool for suspended sediment; and (2) to analyze the relationship between sediment drivers and SSC in a typical agricultural drainage basin. The acoustic and optical backscatter sensors were used to collect SSC data during the ice-free seasons of four consecutive years in the Dunk River (PEI, Canada). The slopes of the relationships between the two SSC indirect measurements were not significantly different than 1. Correlations between SSC and hydro-meteorological variables showed that the high SSC values were more associated with the streamflow and water velocity than precipitation. This study highlighted the great potential of ADCP for the continuous monitoring of suspended sediment in an agricultural watershed. For summer periods the prevalence of clockwise hysteresis (74.1% of measured rainstorm events with SSC > 25 mg L−1) appeared related to rainstorm behaviors.

scholarly journals ACOUSTIC DOPPLER VELOCIMETER BACKSCATTER FOR QUANTIFICATION OF SUSPENDED SEDIMENT CONCENTRATION IN SOUTH SAN FRANCISCO BAY

2017 ◽  
pp. 34
Author(s):  
Mehmet Öztürk ◽  
Paul Work
Keyword(s):  
Suspended Sediment ◽  
San Francisco ◽  
San Francisco Bay ◽  
Empirical Relation ◽  
Acoustic Method ◽  
Sediment Concentration ◽  
Acoustic Doppler Velocimeter ◽  
Data Set ◽  
Suspended Sediment Concentrations ◽  
Optical Turbidity

A data set was acquired on a shallow mudflat in south San Francisco Bay that featured simultaneous, co-located optical and acoustic sensors for subsequent estimation of suspended sediment concentrations (SSC). The optical turbidity sensor output was converted to SSC via an empirical relation derived at a nearby site using bottle sample estimates of SSC. The acoustic data was obtained using an acoustic Doppler velocimeter. Backscatter and noise were combined to develop another empirical relation between the optical estimates of SSC and the relative backscatter from the acoustic velocimeter. The optical and acoustic approaches both reproduced similar general trends in the data and have merit. Some seasonal variation in the dataset was evident, with the two methods differing by greater or lesser amounts depending on which portion of the record was examined. It is hypothesized that this is the result of flocculation, affecting the two signals by different degrees, and that the significance or mechanism of the flocculation has some seasonal variability. In the earlier portion of the record (March), there is a clear difference that appears in the acoustic approach between ebb and flood periods, and this is not evident later in the record (May). The acoustic method has promise but it appears that characteristics of flocs that form and break apart may need to be accounted for to improve the power of the method. This may also be true of the optical method: both methods involve assuming that the sediment characteristics (size, size distribution, and shape) are constant

PSVI-8 Meta-regression Analysis to Determine the Relationship Between Growing Pig Body Weight and Variation

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 218-219
Author(s):  
Andres Fernando T Russi ◽  
Mike D Tokach ◽  
Jason C Woodworth ◽  
Joel M DeRouchey ◽  
Robert D Goodband ◽  
...  
Keyword(s):  
Body Weight ◽  
Regression Analysis ◽  
Sample Size ◽  
Polynomial Regression ◽  
Data Sets ◽  
Regression Equations ◽  
Prediction Equations ◽  
Data Set ◽  
Rate Of Increase ◽  
The Relationship

Abstract The swine industry has been constantly evolving to select animals with improved performance traits and to minimize variation in body weight (BW) in order to meet packer specifications. Therefore, understanding variation presents an opportunity for producers to find strategies that could help reduce, manage, or deal with variation of pigs in a barn. A systematic review and meta-analysis was conducted by collecting data from multiple studies and available data sets in order to develop prediction equations for coefficient of variation (CV) and standard deviation (SD) as a function of BW. Information regarding BW variation from 16 papers was recorded to provide approximately 204 data points. Together, these data included 117,268 individually weighed pigs with a sample size that ranged from 104 to 4,108 pigs. A random-effects model with study used as a random effect was developed. Observations were weighted using sample size as an estimate for precision on the analysis, where larger data sets accounted for increased accuracy in the model. Regression equations were developed using the nlme package of R to determine the relationship between BW and its variation. Polynomial regression analysis was conducted separately for each variation measurement. When CV was reported in the data set, SD was calculated and vice versa. The resulting prediction equations were: CV (%) = 20.04 – 0.135 × (BW) + 0.00043 × (BW)2, R2=0.79; SD = 0.41 + 0.150 × (BW) - 0.00041 × (BW)2, R2 = 0.95. These equations suggest that there is evidence for a decreasing quadratic relationship between mean CV of a population and BW of pigs whereby the rate of decrease is smaller as mean pig BW increases from birth to market. Conversely, the rate of increase of SD of a population of pigs is smaller as mean pig BW increases from birth to market.

Railroad Integration and Uneven Development on the European Periphery, 1870–1910

2021 ◽  
Vol 45 (2) ◽  
pp. 261-289
Author(s):  
Eduard J. Alvarez-Palau ◽  
Alfonso Díez-Minguela ◽  
Jordi Martí-Henneberg
Keyword(s):  
Economic Development ◽  
Positive Impact ◽  
Data Set ◽  
Per Capita Gdp ◽  
Catching Up ◽  
Nation States ◽  
Railroad Network ◽  
Per Capita ◽  
European Periphery ◽  
The Relationship

AbstractThis study explores the relationship between railroad integration and regional development on the European periphery between 1870 and 1910, based on a regional data set including 291 spatial units. Railroad integration is proxied by railroad density, while per capita GDP is used as an indicator of economic development. The period under study is of particular relevance as it has been associated with the second wave of railroad construction in Europe and also coincides with the industrialization of most of the continent. Overall, we found that railroads had a significant and positive impact on the growth of per capita GDP across Europe. The magnitude of this relationship appears to be relatively modest, but the results obtained are robust with respect to a number of different specifications. From a geographical perspective, we found that railroads had a significantly greater influence on regions located in countries on the northern periphery of Europe than in other outlying areas. They also helped the economies of these areas to begin the process of catching up with the continent’s industrialized core. In contrast, the regions on the southern periphery showed lower levels of economic growth, with this exacerbating the preexisting divergence in economic development. The expansion of the railroad network in them was unable to homogenize the diffusion of economic development and tended to further benefit the regions that were already industrialized. In most of the cases, the capital effect was magnified, and this contributed to the consolidation of newly created nation-states.

scholarly journals The Contribution of Urban Morphology to the Formation of the Microclimate in Compact Urban Cores: A Study in the City Center of Thessaloniki

Urban Science ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 37
Author(s):  
Georgios-Rafail Kouklis ◽  
Athena Yiannakou
Keyword(s):  
Field Study ◽  
Urban Form ◽  
Simulation Method ◽  
Urban Morphology ◽  
Green Spaces ◽  
City Center ◽  
Outdoor Spaces ◽  
Microclimatic Conditions ◽  
The Relationship ◽  
The City

The purpose of this paper is to investigate the contribution of urban morphology to the formation of microclimatic conditions prevailing within urban outdoor spaces. We studied the compact form of a city and examined, at a detailed, street plan level, elements related to air temperature, urban ventilation, and the individual’s thermal comfort. All elements examined are directly affected by both the urban form and the availability of open and green spaces. The field study took place in a typical compact urban fabric of an old city center, the city center of Thessaloniki, where we investigated the relationship between urban morphology and microclimate. Urban morphology was gauged by examining the detailed street plan, along with the local building patterns. We used a simulation method based on the ENVI-met© software. The findings of the field study highlight the fact that the street layout, the urban canyon, and the open and green spaces in a compact urban form contribute decisively both to the creation of the microclimatic conditions and to the influence of the bioclimatic parameters.

scholarly journals RESTING HEART RATE MODERATES THE RELATIONSHIP BETWEEN NEUROPSYCHIATRIC SYMPTOMS, MCI, AND ALZHEIMER’S DISEASE

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S641-S641
Author(s):  
Shanna L Burke
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Heart Rate ◽  
Relative Risk ◽  
Neuropsychiatric Symptoms ◽  
Cognitive Status ◽  
Resting Heart Rate ◽  
Data Set ◽  
Increased Risk ◽  
The Relationship

Abstract Little is known about how resting heart rate moderates the relationship between neuropsychiatric symptoms and cognitive status. This study examined the relative risk of NPS on increasingly severe cognitive statuses and examined the extent to which resting heart rate moderates this relationship. A secondary analysis of the National Alzheimer’s Coordinating Center Uniform Data Set was undertaken, using observations from participants with normal cognition at baseline (13,470). The relative risk of diagnosis with a more severe cognitive status at a future visit was examined using log-binomial regression for each neuropsychiatric symptom. The moderating effect of resting heart rate among those who are later diagnosed with mild cognitive impairment (MCI) or Alzheimer’s disease (AD) was assessed. Delusions, hallucinations, agitation, depression, anxiety, elation, apathy, disinhibition, irritability, motor disturbance, nighttime behaviors, and appetite disturbance were all significantly associated (p<.001) with an increased risk of AD, and a reduced risk of MCI. Resting heart rate increased the risk of AD but reduced the relative risk of MCI. Depression significantly interacted with resting heart rate to increase the relative risk of MCI (RR: 1.07 (95% CI: 1.00-1.01), p<.001), but not AD. Neuropsychiatric symptoms increase the relative risk of AD but not MCI, which may mean that the deleterious effect of NPS is delayed until later and more severe stages of the disease course. Resting heart rate increases the relative risk of MCI among those with depression. Practitioners considering early intervention in neuropsychiatric symptomology may consider the downstream benefits of treatment considering the long-term effects of NPS.

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