Coastal Processes - Science topic

A seven-day forecast can accurately predict the weather about 80 percent of the time and a five-day forecast can accurately predict the weather approximately 90 percent of the time. However, a 10-day—or longer—forecast is only right about half the time.

But Extreme Weather Prediction models are yet to reach accuracy

Reduction in water transport improved the water quality during lockdown

yes, you can do that also using eave models, like Delft 3d

Ariel Mohan Aesthetics in cities are not merely a matter of taste, but something that is linked to culture and what is most noble in a community. It reflects a world of meaning about that space and the people who occupy it, in addition to maintaining order and a sense of transcendence. Urban aesthetics is a way to exalt this world of meaning and express the ideals and values of a people. It is not a question of preserving the traditional because it is old, but of preserving the past due to its importance and beauty. Beauty is a spiritual good and, as a spiritual good, it is part of who we are. I recommend reading the attached text.

I would review Springs Stewardship Institute Protocols for springs flow measurement. https://springstewardshipinstitute.org/downloadsandpdfs @Lawrence_Stevens2

there are many mathematical and model based methods are available for shoreline prediction.

the one of the simple method is given below

Future Shoreline Change = Slope * Time interval + Intercept

Inlets to coastal lagoons through sandy barrier beaches exist in a delicate equilibrium between wave-driven littoral drift of beach sand (which tends to close inlets), versus tidal curents and riverine currents (which tend to scour sand from the bed of an inlet and keeps it open). Some inlets open and close seasonally if there is a pronounced rainy season-dry season climate.

If an earthquake suddenly decreases the surface area of a lagoon, or diverts a tributary river away from the lagoon, the balance could be sufficiently upset to allow the littoral drift to close the inlet.

For a world-scale bathymetry grid, the ETOPO1 maps of NOAA can be found here https://maps.ngdc.noaa.gov/viewers/wcs-client/.

For more detailed bathymetry of ocean areas surrounding europe check EMODnet databases: http://www.emodnet-bathymetry.eu/

Data can be obtained in an xyz ASCII format (three columns of x-cordinates (lon), y-cordinates (lat) and z (elevation), or in NetCDF which can be converted to ASCII.

Also naval maps of navionics can be traced for bathymetry in a certain area, http://webapp.navionics.com/?lang=en. Of course local sources are the best choice as the other user suggested.

ThanX Hom..

As far as I know Prof. K. S. Jayappa in Marine science Department of Mangalore University has such data on western coastal area of the Arabian Sea. I do not have his email address.

Dear Sergiu,

Sorry for my late reply, but I have just had the opportunity to read your answer. Thank you very much for this extensive description of sediment movement. I found very interesting your point about the geostrophic currents as they are not wave generated; and yes I will have a look at Leo van Rijn web page.

 Thanks Norman, I will follow that up. I am working in that same estuary myself!

Tubular Immersion heaters are best option. It can be designed to based on Tank dimensions n with a suitable control System ( Panel). We make such heaters.

Dear Fazly,

I recommend you to use this index carefully . It is a relative index, since it is supposed to assign a maximum and a minimum value to your study area. I consider it is really useful in large areas, where the variables mentioned by Daniel ofte show a wide range. But even so, sometimes they do not: we applied to the coast of Andalusia (850 km length), and we did not dare to apply as it is supposed to be applied in the variable "mean tidal range", since our coast ranges from 3.7 meters to 0.4, but nothing else. But strictly, things should not have been done like that.

I recommend it to you to find "where the problems are". And then go to a deeper and more detailed study.

Good luck!

Very interesting question. The bottom current has an effect on detrital input which in turn, may influence the feeding activities of macrobenthic polychaete community.

The following references may help you more.

Regards.

First of all you may want to make sure how the direction measurements you have are computed: for surface buoys, this is usually done from the 1st moments a1 and b1: a1(f)=sum of (E(ftheta) *cos(theta)*dtheta  

b1(f)=sum of (E(ftheta) *sin(theta)*dtheta  

th1m(f)=atan2(b1(f),a1(f))

That gives you a mean direction for each frequency. You can also define an overal direction for a frequency range fmin to fmax (be careful to use the same range in model and data when you compare them). 

see chapter 3 in https://www.researchgate.net/publication/304990310_Ocean_Waves_in_Geosciences

Finally to get statistics, I usually go to complex numbers: Z = (cos theta,  sin theta)  and compute correlations and other things on these complex numbers. 

Hi Moin, please check Ranasinghe and Sato (2007) - Beach morphology behind single impermeable submerged breakwater under obliquely incident waves,” Coastal Engineering Journal 49 (1), 1-24 for some data from small-scale physical models. I think should be good enough for model validation.

The Coastal Vulnerability Index (CVI) is one of the most commonly used and simple methods to assess coastal vulnerability to sea level rise, in particular due to erosion and/or inundation (Gornitz et al., 1991).

Usually, 2D models are used for oceanographic and beach variations because of the large plan area. Maybe Flow3D is useable for variation in small areas!!

It will be nice to analyze clearly the predominant direction and volume of sediment movement per year and into the entry channel of the gulf.  Based on this study, you can design building a smooth curved wall to allow nature to bypass the sediment from one side to other. This way, you can reduce the annual maintenance cost for dredging. We are facing similar problem for a marina in Failaka island in Kuwait and this is the solution e are studying now.

Hi vasudevan

This can be done in many ways according to your choice of platform or software.

Data visualisation and analysis tools like Ferret, Matlab,cdo etc  will do your needs.

sample script in matlab to do it : modify according to ur need

s=dir('filename.nc')  %%% load ur files

nc_dump(s(1).name) %% see the description of variables

lat=nc_varget(s(1).name,'lat'); %% change the varible name as in ur file

lon=nc_varget(s(1).name,'lon');

uwnd=nc_varget(s(1).name,'u10');

vwnd=nc_varget(s(1).name,'v10')

windspeed=sqrt(u.^2+v.^2);

(PLZ  note For matlab  sometimes u may need SNCTOOLS for carrying out the analysis with netcdf files : http://mexcdf.sourceforge.net/ )

best regards

shanas

You can use MODIS data. To gain more information about its products, you can refer to the following publication:

Antonios,

Please have some refs. attached; perhaps general but maybe they will help.

Best regards,

Greg

Why not? I am wondering if coastal erosion studies have been carried out with moderate resolution satellite data such as Landsat, then why not use Google Earth with much better resolution sometimes even to centimeters of spatial resolution. I came across a Featured article in NASA Earth Observatory on Coastal erosion in the East Coast of US (link attached). Although they have used Landsat Images from the past 30+ years, you can download the kml file (link attached) and study the area with the historical imagery slider on Google Earth. I think it is a very useful image analysis tool. Gives you much better perspective and more importantly you can make quantitative measurements of shoreline change rates. Having said that, I think for Coastal Geologists, Engineers and Planners Google Earth is an excellent tool for studying shore line changes and coastal features. I am sure you will find more examples on the web if you search.

I would be interested to read what others have to add against using Google Earth for coastal erosion studies..

With 1D model, you can use Sbeach, Xbeach, Duros Plus, Litpack, Genesis, Unibest-CL,  to simulate erosion beach or dune.

With 2D model, you use more model as Delft 3D, Telemac, EFDC.

Dear Saman

As Prof.Towe said, your question is so opaque. I can't imagine it. Could you please explain your question step by step? Maybe after that, I'll understand your aim.

Thanks

I know such author - Efim Pelinovsky - who has studied the theory of wave propagation in the ocean, including nonlinear. For example, this book is on the emergence of extreme ocean waves as a product of nonlinear wave interaction:

Efim Pelinovsky, Christian Kharif, eds. "Extreme Ocean Waves" Springer 2008

He also has many papers on the evolution of tsunami waves. For tsunami wavelengths all the ocean is shallow water since they are long comparing to depth. You can find more of his publications on his RG page: https://www.researchgate.net/profile/Efim_Pelinovsky/contributions

Hello 

I hope this may help

Application of telemac:

Horritt, M. S., and P. D. Bates. "Evaluation of 1D and 2D numerical models for predicting river flood inundation." Journal of Hydrology 268.1 (2002): 87-99.

Yu, Dapeng, and Stuart N. Lane. "Urban fluvial flood modelling using a two‐dimensional diffusion‐wave treatment, part 1: mesh resolution effects." Hydrological Processes 20.7 (2006): 1541-1565.

Awad, Mohamad, and Talal Darwich. "Evaluating Sea water Quality in the Coastal Zone of North Lebanon using Telemac-2D TM." Lebanese Science Journal 10.1 (2009): 35.

Horritt, M. S., and P. D. Bates. "Predicting floodplain inundation: raster‐based modelling versus the finite‐element approach." Hydrological processes 15.5 (2001): 825-842.

Bates, Paul D. "Flood Routing and Inundation Prediction." Encyclopedia of Hydrological Sciences (2005).

Other methods:

STRATIGAKI, Vasiliki, et al. Large-scale experiments on wave propagation over Posidonia oceanica. Journal of Hydraulic Research, 2011, 49.sup1: 31-43.

SÁNCHEZ-GONZÁLEZ, José Francisco; SÁNCHEZ-ROJAS, Virginia; MEMOS, Constantine Demetrius. Wave attenuation due to Posidonia oceanica meadows. Journal of Hydraulic Research, 2011, 49.4: 503-514.

INFANTES, Eduardo, et al. Effect of a seagrass (Posidonia oceanica) meadow on wave propagation. Marine Ecology Progress Series, 2012, 456: 63-72.

MANCA, E., et al. Wave energy and wave-induced flow reduction by full-scale model Posidonia oceanica seagrass. Continental Shelf Research, 2012, 50: 100-116.

KOFTIS, Theoharris; PRINOS, Panayotis; STRATIGAKI, Vasiliki. Wave damping over artificial Posidonia oceanica meadow: A large-scale experimental study. Coastal Engineering, 2013, 73: 71-83.

CAVALLARO, Luca, et al. Response of Posidonia oceanica to wave motion in shallow-waters-preliminary experimental results. Coastal Engineering Proceedings, 2011, 1.32: waves. 49.

PRINOS, PANAYOTIS; KOFTIS, THEOHARRIS; GALIATSATOU, PANAGIOTA. Wavelet analysis of wave propagation over Posidonia Oceanica. In: Proceedings of Coastlab10 Conference, Barcelona, Spain (full paper in CD-ROM). 2010.

KOFTIS, Theoharris; PRINOS, Panayotis. Estimation of wave attenuation over Posidonia Oceanica. In: th 5 SCACR 2011 International Short Conference on Applied Coastal Research. 2011. p. 264.

Kind regards

An approach we are using is using squared distance weighted interpolation:

u=(u1/r1^2+u2/r2^2+u3/r3^2+u4/r4^2)/(1/r1^2+1/r2^2+1/r3^2+1/r4^2)

where u is the sought for speed, r1, r2, ... are the distances and u1, u2, ... are the wind speeds at the four grid points.

Best regards

Takvor

thank you Mr. Van

Dear Shahrouz,

SLR is a very trick proposition. A better term would be relative sea level rise. There are several projections by different group of scientists who have different values. I do not have exact values for your regions. But being a Gulf region precise calculations would have to be done for your area.

Try it yourself,

I think you can be successful.

As a student PhD. you may obtain a free, time-limited license for MIKE Powered by DHI software.

Juan Carlos,

There is excellent experience in the UK with beach replenishment in macro-tidal ranges - especially gravel beach replenishment. The CIRIA Beach Management Manual (2010) is perhaps the "go to" information source for our practitioners when considering a potential scheme. It was free to download for those registering onto CIRIA's website back in 2010/11 when it was published. From what I can see the free download has been discontinued. Do try to see if you can find a free download from CIRIA, but if not a wider web search for a download of the manual might be productive. This manual is absolutely excellent and I really cannot recommend it strongly enough - its vital for all applied coastal scientists working in macro- and meso- tidal environments!

I estimate the challenges involved with beach replenishment in macro-tidal environments as follows:

1. Potentially large quantities of recharge sediments would be required to cover the long cross-shore profiles. This is a key issue with sand recharge as beach gradients are lower and profiles are longer. A second related problem is that its very difficult to control longshore transport losses using groynes as the long profiles mean that groynes would need to be uneconomically long and high. A successful scheme I know in this category is the "Lincshore" replenishment on the Lincolnshore coast (tidal range 5 to 7m). Its a very large and expensive scheme that has involved several cycles of replenishment, but it is seen as sustainable as the beach performs very important coastal defence and amenity functions and there are appropriate sources of marine dredged sand available. a paper can be downloaded from the following link: 

At Blackpool  (8m tidal range) the UKs largest coastal resort town has been protected by a major new sea wall rather than a replenishment scheme due to concerns about the quantity of replenishment sand required and its potential stability on the beach if constructed. 

2. There are concerns of offshore loss of replenished sediments in areas with high tidal range. Risks are lessened in the case of your beaches since the short fetches mean lesser exposure to high storm waves. However, there are also risks of sediment loss due to tidal currents if there are any tidal channels or fast flowing currents near to the toes of your beaches.

A solution would be to consider gravel rather than sand replenishment as gravel is preferentially retained on the upper portion of the beach profile and is less easily transported seaward during storms - also it generates steeper and shorter profiles. It does however remain susceptible to losses if there are tidal channels adjacent to the toes of your beaches. Best practice is to try to source replenishment sediment that is on average a little coarser than the indigenous gravel at your beach. Its OK if there are some finer sediments incorporated, but large quantities of intermixed sand are not recommended as it can significantly reduce beach porosity and hence increase risks of offshore losses in the early stages before the replenished beach can become naturally sorted. If there is significant drift on your beaches then you may wish to consider using short rock groynes to control the upper beach. Another possibility could be to use a longer terminal groyne at the downdrift end of a beach to collect drifting gravel and then excavate and truck it back updrift and reintroduce it to the beach (recycling). Good beach monitoring is required to optimise such management operations.

If appropriate sources of gravel for replenishment are not available reasonably close to your intended scheme sites then you may wish to consider a sea wall and/or rock revetment scheme. If your beaches are heavily depleted be aware of the potential problem of wave reflection and toe scour that can be caused by constructing sea walls on such beaches.

I hope the information is useful and I wish you success in your feasibility studies.

Hello Atteleth, 

I personally don´t think you should use the advection/dispersion module from MIKE 21, which takes into account decay of the modeled substance. What you can do is do a MIKE 21 HD simulation and then in plot composer add particules. This particules will move according to the hydrodynamics in your modelling and they can give you an idea of how the propagule will distribute in your study area. An alternative is to use the ABM from MIKE 21, which allows you to determine how the propagule will propagate, but since they are only floating, then I guess there is no point on complicating your study!

I hope this helps. Cheers.

Hola Juan, if you look at Figure 3a in the below from Pisco Peru 2007 tsunami you will see a tsunami runup induced slump and wrackline on Playa Tunga along Bahia de la Independencia’s desert coastline (sandy desert beach and continuous desert sand inland). This location is south of the Paracas Peninsula in Peru.

Fritz, H.M., Kalligeris, N., Borrero, J.C., Broncano, P., Ortega, E. (2008). The 15 August 2007 Peru tsunami runup observations and modeling, Geophys. Res. Lett., 35, L10604, doi:10.1029/2008GL033494.

You may find out some information at:

Vasko, Lyubka, Haider, Hilmi,

Thanks a lot for your response to my question. I will look at the recommended papers and may come with more specific questions.

Kind regards,

Boyan

You can find a brief description of varius methodologies in :

Balouin.Y., Howa.H., Pedreros.R., Michel.D. (2005) Longshore sediment movements from tracers and models, Praia de Faro, South Portugal., Journal of Coastal Research, Vol. 21, n°1, pp. 146-156.

Deltaic systems are so dynamic (on a spatio-temporal scale) to a level that it is near impossible to estimate their variations. Further, 5km is too great a distance that may show numerous variations.

I have simulate sediment and flow interaction using Moving Particle Semi Implicit method which is a particle method same as SPH. As you may know, MPS and SPH are the most similar methods among other Lagrangian methods. Please, feel free to ask your question on the issue.

Dear Tran Thanh

Yes, there is, provided the beach slope and mean grain size are both measured at mid-tide level. This was already shown by Bascom (1951) Relationship between sand size and beach face slope. Transactions American Geophyssical Union 32:866–874. This simple empirical approach does not require any high-tech equipment other than an angle meter (e.g. a Bevel-Box) but still gives a very good first-order impression of beach morphodynamic state and its temporal evolution if slope angles (and mean grain size) are measured frequently at the same location(s). An improved plot can be found in Flemming (2011: Geology, Morphology, and Sedimentology of Estuaries and Coasts, page 17-19, Fig. 13) and Flemming and Göttisheim (2013: Geo-Marine Letters 33, Fig. 8). Both papers can be downloaded from my publication profile in ResearchGate.

Best regards

Burg Flemming

Thanks Clark,

Good answer for everyone. Since I never used EB before I was confused a bit, but for the future I'll be careful (for both EB and EA).

Good luck and hope to see you soon!

Fred

In general set the coastline using remote sensing techs is quite tricky. According to my experience the accuracy of any methods depends on the amount of field data you have (number of images, local tide prediction, wave climate, etc). That's why we had been using Video cameras in conjunction with tide measurements and topographic surveys to set the coastline position. Using such a system you will be able to build a huge database of coastlines for each wave-tide condition. There are many algorithm to estimate the coastline position from video images (i.e: Plant et al., 2007 "The Performance of Shoreline Detection Models Applied to Video Imagery" and Almar et al., 2012 "Video-Based Detection of Shorelines at Complex Meso–Macro Tidal Beaches"), but none of them work for all conditions. Changes in light, bright, solar radiation, clouds, sand reflectance, etc may affect the detection process and also the accuracy of the method. However, those methods may work with satellite images as well.

For a more general view on RS techniques applied for Shoreline detection see Moore (2010) "Shoreline Mapping Techniques".

Hope it will be helpful

The scatterring produced by gases and aerosols in the atmosphere are very important for remote sensing techniques in the visible and near infrared regions. Aerosol particles visible in satellite imagery can also be used to study dust storms, wildfire smoke, volcanic ash and urban pollution dispersion. Aerosols also influence the earth radiative heat budget and are one uncertainty in studies prediction global climate change. That´s is a very short answer to your question. The are several books about atmospheric aerosols. Ex: http://www.amazon.com/dp/3540262636/ref=rdr_ext_tmb

you may have a look to Sabatier et al., 2005 (JCR) and Brunel and Sabatier 2009 (Geomorphology) if century scale is your interest.

The following two papers provide a good overview of the effect of tide range and displacement on beach morphology

Masselink and Short (1993) The effect of tide range on beach morphodynamics and morphology: a conceptual beach model.

Short (1996) The role of wave height, period, slope, tide, range and embaymentisation in beach classifications: a review

The ratio would depend on source area composition. For example, if the mudflat sediments are derived from felsic sources, the ratios would be different from those derived from mafic sources.

I don't have an answer. Just to say that I'm interested too in knowing data base of shoreface slopes.