scholarly journals RATE OP SEDIMENT MOTION USING FLUORESCENT TRACER

1972 ◽  
Vol 1 (13) ◽  
pp. 49
Author(s):  
Abdel-Latif Akadib
Keyword(s):  
Rational Design ◽  
Drift Rate ◽  
Sandy Beaches ◽  
Beach Erosion ◽  
Remedial Measures ◽  
Natural Conditions ◽  
Littoral Drift ◽  
Tracer Concentration ◽  
Fluorescent Tracer ◽  
Study Zone

A rational design of coast protection works requires a knowledge of the behaviour of beach under natural conditions. The estimation of the littoral drift rate is thus a necessary preliminary to the analysis of the cause of beach erosion and the evaluation of the effect of projected remedial measures. This study presents a method for estimating the rate of littoral drift along sandy beaches. The derived method is based on the use of fluorescent tracer, and observing the tracer concentration reaching the different profiles along the study zone, as function of location and time of sampling. Steps followed in estimating the rate of littoral drift, using the derived formula, are included in this paper.

scholarly journals Are saltflats suitable supplementary nesting habitats for Malaysian Plovers Charadrius peronii threatened by beach habitat loss in Thailand?

2007 ◽  
Vol 17 (3) ◽  
pp. 211-223 ◽  
Author(s):  
Maï Yasué ◽  
Allison Patterson ◽  
Philip Dearden
Keyword(s):  
Hatching Success ◽  
Low Cost ◽  
Sandy Beaches ◽  
Beach Erosion ◽  
Breeding Habitat ◽  
Success Rates ◽  
Large Area ◽  
Air Temperatures ◽  
Aquaculture Ponds ◽  
Resort Development

AbstractResort development and coastal beach erosion have led to declines in beach breeding habitat for the near-threatened Malaysian Plover (Charadrius peronii) in the Gulf of Thailand. Semi-natural saltflats may provide supplementary nesting areas. We compared the environmental conditions, incubation behaviour and nesting success of plovers breeding on sandy beaches and saltflats in Thailand. In total we monitored 21 and nine nesting attempts in 2004 (beaches and saltflats, respectively) and 26 and 22 nesting attempts in 2005. Despite higher air temperatures in the saltflats (P < 0.0001), we detected no significant differences in nest attendance (P = 0.542 and P = 0.885 for 2004 and 2005, respectively), number of incubator changes between parents (P = 0.776 and P = 0.823) or number of parental nest departures (P = 0.087 and P = 0.712) during 120 incubation observations on 55 nests. There was also no difference in hatching success between beaches in 2004 (beach = 0.65, saltflat = 0.55; P = 0.692, n = 26) and 2005 (beach = 0.46, saltflat = 0.35; P = 0.539, n = 41). These results suggest that saltflats may provide nesting habitat for Malaysian Plovers and could help enhance overall hatching success rates by reducing nesting densities on beaches. Although there are few remaining intact saltflats in coastal Thailand, there are currently vast areas of abandoned tiger prawn aquaculture ponds that could be rehabilitated into saltflats at relatively low cost. Given the large area of disused aquaculture ponds throughout Thailand and South-East Asia and the substantial human pressure on coastal habitats, there could be considerable conservation benefits to the restoration of aquaculture ponds.

Quantitative analysis of debris torrent hazards for design of remedial measures

1984 ◽  
Vol 21 (4) ◽  
pp. 663-677 ◽  
Author(s):  
O. Hungr ◽  
G. C. Morgan ◽  
R. Kellerhals
Keyword(s):  
Rational Design ◽  
Design Tool ◽  
Provincial Government ◽  
Remedial Measures ◽  
Runout Distance ◽  
Organic Debris ◽  
Discharge Velocity ◽  
Frequency Peak ◽  
Retention Barriers ◽  
Run Up

Debris torrents, which are rapid flows of soil and organic debris down steep mountain channels, are a major natural hazard in many parts of British Columbia.A series of recent occurrences along the Squamish Highway, north of Vancouver, led the provincial government to initiate a systematic study of debris torrents in this area. This 2 year study involved hazard risk assessment and resulted in the design of a comprehensive system of remedial measures comprising debris retention barriers and basins, channel improvements and diversions, and the reconstruction of bridges. It was necessary in the course of this effort to formulate new design procedures covering the dynamic behaviour of debris torrents, as there was no accepted practical methodology suitable for Western Canadian conditions.This paper provides an approach to determining magnitude (volume of debris material involved), frequency, peak discharge, velocity, conditions for deposition, runout distance, behaviour in bends and run-up against barriers, and dynamic thrust and impact loadings. The procedures are based on some of the more practical concepts available in the specialized literature, supplemented by simple original theories and calibrated against several recent debris torrent events from British Columbia for which sufficiently detailed observational data exists. To be generally applicable, the procedures require a wider and more thorough calibration. They are presented here as working hypotheses that can be used as a guide to the assembly of additional data and provide a rational design tool to supplement the application of experience and judgement. Key words: debris torrents, debris flows, slope hazards, landslide dynamics, remedial measures, engineering design.

scholarly journals Beach Erosion and Consequential Impacts Due to the Presence of Harbours in Sandy Beaches in Greece and Cyprus

2015 ◽  
Vol 2 (S1) ◽  
pp. 55-71 ◽  
Author(s):  
V. K. Tsoukala ◽  
V. Katsardi ◽  
K. Ηadjibiros ◽  
C. I. Moutzouris
Keyword(s):  
Sandy Beaches ◽  
Beach Erosion

EFFECTS OF THE IXTOC I OIL SPILL ON THE INTERTIDAL AND SUBTIDAL INFAUNAL POPULATIONS ALONG LOWER TEXAS COAST BARRIER ISLAND BEACHES

1981 ◽  
Vol 1981 (1) ◽  
pp. 467-475 ◽  
Author(s):  
Larry C. Thebeau ◽  
John W. Tunnell ◽  
Quenton R. Dokken ◽  
Mary E. Kindinger
Keyword(s):  
Oil Spill ◽  
Sandy Beaches ◽  
Beach Erosion ◽  
Seasonal Fluctuations ◽  
Population Densities ◽  
Texas Coast ◽  
Tropical Depression ◽  
Intertidal Population ◽  
Abundance And Diversity ◽  
The Impact

ABSTRACT Pre-spill (August 4 to 11, 1979) and post-spill (September 24 to 29, 1979) sampling of intertidal and subtidal infaunal populations along lower Texas coast sandy beaches was conducted to determine the impact of the Ixtoc I oil spill. Transects sampled between the Rio Grande and Port Aransas produced 52 species of macroinfauna primarily dominated in abundance and diversity by polychaetes and haustoriid amphipods. Analyses revealed visible, though not significant, decreases in pooled intertidal population densities and significant reductions in pooled subtidal population densities. Numbers of species did not significantly change. Population density changes may have been caused by Ixtoc I impact, tropical depression/storm beach erosion, seasonal fluctuations, beach cleanup techniques, or a combination of these.

scholarly journals THE RELATIONSHIP BETWEEN WAVE ACTION AND BEACH PROFILE CHARACTERISTICS

2011 ◽  
Vol 1 (7) ◽  
pp. 14 ◽  
Author(s):  
P.H. Kemp
Keyword(s):  
Rational Design ◽  
Break Point ◽  
Coarse Sand ◽  
Beach Erosion ◽  
Beach Profile ◽  
Model Study ◽  
Materials Used ◽  
Profile Characteristics ◽  
The Relationship ◽  
The Waves

The rational design of coast protection works requires a knowledge of the behaviour of the beach under natural conditions. The understanding of the relationship between the waves acting on the beach and the characteristics of the beach profile produced, is thus a necessary preliminary to the analysis of the causes of beach erosion and the evaluation of the effect of projected remedial measures. The present paper describes the results of a series of preliminary hydraulic model experiments carried out by the author prior to a model study of the behaviour of groynes in stabilising beaches. Most of the beach materials used represented coarse sand or shingle in nature. The results demonstrate the fundamental importance of the "phase difference" in terms of wave period between the break-point and the limit of uprush, in relation to flow conditions, cusp formation, and the change from "step" to "bar" type profiles. Within the limits of the experiments an expression connecting the breaker height, beach profile length, and grain diameter is developed, and its implications examined in relation to beach slope, and to the previous "wave steepness" criterion for the change from step to bar type profiles. Observations are included on the rate of recession of a shoreline due to the onset of more severe wave conditions.

scholarly journals PHYSICAL MODELLING OF BEACH EROSION AND LITTORAL DRIFT

1988 ◽  
Vol 1 (21) ◽  
pp. 134 ◽  
Author(s):  
Otavio J. Sayao ◽  
Robert B. Nairn
Keyword(s):  
Grain Size ◽  
Physical Model ◽  
Scale Effects ◽  
Physical Modelling ◽  
Beach Erosion ◽  
Model Design ◽  
Littoral Drift ◽  
Sedimentary Processes ◽  
Dynamic Similarity ◽  
Proposed Model

A new procedure for physical modelling of beach sedimentary processes is presented. It is shown that the modelling requirements proposed by Dean (1985) are necessary but not sufficient for dynamic similarity. Quantification of scale effects due to slope and relative grain size scaling conditions enables extrapolation of the physical model results to prototype situations. Selected examples of the application of the proposed model design are also given.

scholarly journals An application of fluorescent tracer to groundwater tracking

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Vigilija Cidzikienė ◽  
Vaidotė Jakimavičiūtė-Maselienė ◽  
Raselė Girgždienė ◽  
Rūta Ivanec-Goranina
Keyword(s):  
Flow Direction ◽  
Unconfined Aquifer ◽  
Natural Conditions ◽  
Fluorescent Tracer ◽  
Injection Wells ◽  
Hydraulic Connection ◽  
Nuclear Site ◽  
Flow Velocities

AbstractA well network at a potential new nuclear site in Lithuania examined a semi-confined intertill aquifer 10–19 m deep and an unconfined aquifer 4.5–9 m deep. Tracer results indicate a northwest flow direction and great hydraulic connection between observation and injection wells. Natural conditions affect tracer flow velocities.

scholarly journals A Class of Probability Models for Littoral Drift

1970 ◽  
Vol 1 (12) ◽  
pp. 52
Author(s):  
William R. James
Keyword(s):  
Average Rate ◽  
Accurate Method ◽  
Sediment Flux ◽  
Transport Rate ◽  
Constant Thickness ◽  
Burial Depth ◽  
Tracer Transport ◽  
Probability Models ◽  
Littoral Drift ◽  
Tracer Concentration

The major goal in the development of sediment tracer technology is to produce an accurate method for the field measurement of short term volume littoral rate Many of the technical difficulties involved in tagging, injecting, and sensing the movement of radioisotope sand tracers in the littoral zone have been overcome by the RIST project However, quantitative determination of volume drift rate requires more than knowledge of tracer position in time and space A mathematical model is required to relate the flux of tracer material to the sediment flux A linear (or average) rate of tracer transport along the coastline can be measured to a fair degree of accuracy with tracers These measurements, when determined from tracers injected along a line source which span the transport zone, can be used to provide an estimate of an areal transport rate However, it is not obvious how to measure the third dimension, depth of transport This, of course, is needed to provide the desired estimate of volume transport rate This problem arises, even if the relation of tracer concentration to burial depth is everywhere known without error Sediment transport does not occur as a sheet of constant thickness moving at a constant rate If this were so tracer concentration would rapidly attain a uniform concentration over a fixed depth and no tracers would appear below that depth In fact no observations of the relation between tracer concentration and burial depth support this model as even a first approximation Studies such as those of Courtois and Monaco (1969) and Hubble and Sayre (1964) suggest that the concentration of tracers is related to burial depth in a complex fashion The concentration on the surface is finite, but not maximal The concentration increases with depth to some point where a maximum is reached and diminishes in a "long tailed" fashion.

Sign in / Sign up

Export Citation Format

Share Document