Coastal Geomorphology - Science topic

There are several potential reasons, which are hard to distinguish based on what you've written. However, the 'obvious' answer is that sediment transport is ALWAYS a timescale-dependent parameter. The cumulative answer will always be larger the shorter the timescale you are applying it to. This was discussed in some seminal papers like de Vriend et al (1991) and Cowell et al (2003), along with some discussion by Pilkey. For a 'light version' try Gallop et al (2015). It is one of the concepts behind 'morphological' parameters.

I had the same problem and solved it by working on preprocessing. My steps were: Digitize the shorelines (with a fixed zoom scale) and create a baseline on the mainland, you may have to create both on the mainland and on the water (depending on our region). You must use shapefiles in the same coordinate system, and must be based on meters (UTM). In the case of your shorelines had been digitalized in different shapefiles, use the "Merge" tool to join all shorelines in one shapefile. In ArcCatalog, click with the right bottom in the folder you want to put your geodatabase, so go to "New" and in "Personal Geodatabase". After that, with a double click in the archive just created, click with the right bottom in the space of it, and go to "Import" to put there two shapefiles, one with your shorelines and other with the baseline(s).

Some classes and their types are required, so you should check if your shapefiles have:

- Baseline:

--> User created: id (Long Integer)

--> Created by DSAS through Attribute Automator: SHAPE_Length (Double), DSAS_ID (Long Integer)

- Coast:

--> User created: id (Long Integer), Uncy (Double), Date_ (Text).

--> Created by DSAS via Attribute Automator: DSAS_date (text), DSAS_uncy (Double), DSAS_type (text)

I leave the uncertainty field (Uncy) empty and DSAS defaults to 10 meters in this case. After that, I used the DSAS video (https://www.usgs.gov/media/videos/introduction-dsas-v50-sample-data-workflow) as a guide.

I can't find a summary Amaal, but you can look inside parts of the Ebook version here

Convey my thanks for such a relevant article that nicely elaborated of the carbon draining from the terrestrial forest floors arrested in the mangroves ecosystems and that is seen at a glance, I will go through the paper later on and use as citation in my work

The accuracy of the UAV-derived digital surface models was assessed against equivalent topographic profiles via root-mean-square error and found to be <0.21 m based on Lowe et al., 2019.

Lowe, M.K.; Adnan, F.A.F.; Hamylton, S.M.; Carvalho, R.C.; Woodroffe, C.D. Assessing Reef-Island Shoreline Change Using UAV-Derived Orthomosaics and Digital Surface Models. Drones 2019, 3, 44.

You used Modis and Sentinel 3 data for SPM mapping

Delft 3D is a good choice

I used a quadcopter for scanning areas and develop a new map for the area to use it for civil engineering in new projects

This study is novel, I am also carrying out a similar research over the Gulf of Guinea. You would need to access the topographic data from the USGS data archive, there you can download the actual SRTM/ASTER(DEM) data covering your study area. After the data acquisition, you can then perform datum conversions and re-projections. Then, you can process the Digital Elevation model for the area using Spatial Analyst tools, creating TINs, etc.

You will then calculate the levels of sea surface heights at varying distances from the shoreline.

If you have access to LIDAR images, It would generate a better inundation results.

check out this article for further explanation.

Nicolas Pucino Yes, some organic material will likely dissolve depending on soak time and temperature, and quality of OM. However, if you are not concerned with sub-ppt resolution, I cannot imagine that the loss would be significant. A simple trial with a few test specimens may reveal how much mass change is associated with the water extraction.

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

Nitesh Patidar Thx for your suggestions!

Thank for sharing your views Harald G. Dill .

I will keep on investigating until I find an optimal solution.

Best Regards,

Nick

Dear Aleksandr Danchenkov,

I recently read a paper on coastal geoindicators and I think there are some references in it which could be helpful. See : Coastal geoindicators: Towards the establishment of a common framework for sandy coastal environments. @ Carapuço et al., 2016. Textbook and Encyclopedia on coastal geomorphology or coastal science will aslo help you.

Thank you Jan Kinne and Federico Solano the error was very simple to solve. In the guide to program appears the solution.

"The computer must be configured to English (USA) and the date format must be mm/dd/yyyy. From the Control Panel menu, choose 'Regional Configuration and Language'> select 'English (USA)' and modify the date configuration to 'mm/dd/yyyy.'"...

Thanks for answering my question.

Yes, as you have rightly understood, it a complex delta system criss-crossed by mighty estuarine rivers; innumerable creeks; tributaries and mangrove forests. Thanks Dr. Bayan for the map, which serves as a ready reference to the RG readers.

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.

check for the very-high resolution oxygen isotope reference curves, especially in papers based on DSDP sites.

Procure 3 axis digital magnetometer

To model and mapping longterm shoreline changes, you can use DSAS (Arcgis). If you prefer open software you can also use Station Lines plugin (QGIS). 

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.

Please check the below given link and PDF attachments.

You may want to look into CJ Jackson's work using AMBUR software he developed.  Here is a document that may assist in your search:  http://southatlanticalliance.org/wp-content/uploads/2014/09/05-CJ-AMBUR-HVA-GSAA-4th-Annual-Meeting.compressed.pdf

Here also is a project that may provide useful information for you:  https://coast.noaa.gov/digitalcoast/stories/delawarebay.html

Dear Jack, to resolve the question I suggest you a digital terrain model software as Surfer (Golden Software), simply to use. This sw can interpolate/extrapolate georeferenced points, considering the lake shore as a blanket file (impassable), and elaborate curves from your data (through the kriging, minimum curvature or other algorithm) imported/digited in a worksheet. Is possible to obtain in few minutes 2D and 3D maps (DTM, DEM, vector maps, etc.) of both emerged and submerged landscape/parameters. You could test it as free trial: http://www.goldensoftware.com/products/free-trial

Get a look at the overview...

Best, Carlo

Hi,

See the PDF and link bellow.

Good Luck.

Hi Nadia there is a website that contains tidal gauges hourly datasets of 5 local stations in northern part of IRAN (ANZALI / CHALUS / AMOL / BABOLSAR and BEHSHAHR stations ) considering the website is IRNIAN and due to linguistic difficulties I can help you with downloading the data if it is needed.the address link is as follows :

also check : http://subsite.caspinfo.net/caspinfo/edmed.jsp

Dear Francesco,

You may obtain some crude chronological estimate by trying the following:

A) Select the robust taxa and observe their taphonomic state (abrasion, disarticulation, fragmentation, secondary rounding, etc.).

B) Note the annual input rate (seasonally variable) of the chosen taxa and the rate of taphonomic changes with time.

C) Use data from steps A and B to infer the antiquity (very rough estimate only) of the rehash assemblage.

Best wishes

Dear Debasish 

The samples that you have posted , was living or fossil stage ? 

Best 

Aravinda 

Hello David,

Please get in touch with Joseph M Maina of the University of Queensland. That is his expertise, you can visit his researchgate profile at  https://www.researchgate.net/profile/Joseph_Maina8 and also his google page for his publications at https://scholar.google.com/citations?user=Go7V_2AAAAAJ&hl=en

I am also appending one of his recent publications on a study on coral reefs in Madagascar.

Goodluck,

Beckline.

Hi Ridel!

With your question you are addressing a highly complex issue for which there is no simple solution. For all we know, mean global sea level is currently rising at  an average rate of about 1 mm/year or 10 cm/century. Contrary to the claim by NOAA, there is no evidence for an acceleration in the rate of sea level rise, their satellite altimetry data having been unjustifiably manipulated, as recently revealed by Mörner (and conceded by NOAA).

Thus, accepting an average global rate in sea level rise of 10 cm/century since the end of the Little Ice Age, one can offhand say that it is quite impossible to extract this signal from beach morphodynamic and sea level data in the short term because the scale of both by far exceeds the scale of sea level rise (by several orders of magnitude in both the vertical and horizontal). A possible approach would be to trace the landward displacement of the storm high-water line (transition from sand to vegetation) over as long a period as possible, but several decades at the very least. Aerial photographs would be a great asset if they are available (consult Offices of the Surveyor General).

Numerical models are of little value because the output entirely depends on the completeness and accuracy of the input data. Irrespective of how incomplete these data are, a model always gives you an answer, the reliability of which, however, is entirely unknown. Such exercises can therefore serve as useful background information but not as a solution.

As far as individual beaches are concerned, one needs to assess the overall sediment budget, i.e. whether, and if yes, what the magnitude and rate of sand supply from external sources is (streams, coastal erosion, longshore transport). As already pointed out by  Norman and Alexander above, you also need to pay attention to (perhaps) cyclical changes in wave climate induced by, e.g. the change from El Nino to La Ninja conditions, as well as regional tectonic (and neotectonic) crustal movements.

I hope my comments are of some use. You are certainly tackling a formidable but nevertheless challenging issue. Good luck with it.

Regards, Burg

My suggested answer is the work of U.S. Navy Lieutenant Matthew Fontaine Maury, who (1) compiled weather and sea condition information from old sailing logs, (2) asked outbound sea captains to keep regular logs of weather and sea conditions and send them back to him, (3) offer each participating sea captain a set of new nautical charts with compiled information included, and (4) published the compiled information in several books, starting about 1850.  See http://www.oldsaltblog.com/2011/11/the-wave-glider-of-2011-and-matthew-fontaine-maury-of-1850/.  (One of my ancestors was such a participating captain.)

You might also check out Onset Hobo data loggers. The old versions several decades ago were very inexpensive, and needed to be contained in a water proof capsule.  To save funds, extra protection was added with plastic whirl-pak bags as very inexpensive. The new data loggers are likely better and more expensive, and some issues with people finding and damaging, so se started to include a note on who to contact, what the temperature recorders were doing to help identifymand improve fish habitat.  I have had good results with them (Hobos) as long as not damaged,,stolen or taking on water.  The technology has improved in the last 20 years.  I have not used Tinytag, but in an earlier researchgate question, some individuals found them reliable.  I made sure we secured them in sections of plastic pipe that were cabled to strong roots or other relatively immovable oblects, hand burying cable under rocks if available to obscure detection.  It is important to provide map and description of location if the person installing will not be servicing the data loggers, perhaps even capture a picture of site.  If stream is likely to be intermittent, you may want to locate in pool, but I usually preferred sections with more velocity to avoid sediment burial if evident.

PDF, Thanks to all. Regards

Abrasion is a term mainly related to rocky shores. Coastal erosion is a wide concept. More agents are involved in it.

Before you even start to develop an instrument to measure the bed level you have to ask yourself, "How do I define the bed level?". What is "the bottom"? Sometimes it is very clear, but at other times what visually is the bottom is not what one would define as the bottom if probing with a stick. Fluid mud looks like the bottom but a diver can swim through it. Second, for what purpose do you need to know the bottom level? The SediMeter was developed to detect sediment transport. If the sediment transport takes place through migrating bed forms the resolution does not have to be that high, or if there is net accumulation or net erosion. But if the sediment transport takes place as sheet transport, bedload over a flat bed that does not change level, then the instrument needs to be able to detect very small changes. If it can detect the addition or removal of a single grain of sediment, then it for sure has sufficient resolution. As far as I know, only the SediMeter is capable of doing that, and that was the original purpose of me developing it 31 years ago.

There is usually a significant diurnal cycle in wind speeds. At coastal stations, the diurnal cycle is often even much larger than on land due to the sea-breeze system. So if you have less observations, you may end up using the time of the day where wind speeds are on average always higher or lower than using another time of the day etc. Changing the number of observations will always change the mean value systematically.

As an example, see the figure for the daily cycle of different wind farms and imagine you change the time or sampling rate... It will significantly impact the daily/annual mean. I just took one of the first examples I found on that - it may be very different for your location.

Hi Nicolas, it is good to hear about people doing monoplotting with oblique photography!  Thanks to you and to the other specialists giving feedback.

I have no experience extracting features from this kind of material, but I have a bit of experience in doing monoplotting (with ILWIS-ITC, there is a free downloadable academic version) and working with traditional photogrammetric photos (close to vertical).  Also, if you have the opportunity, test the PHOTOMOD software (a russian product), that is very powerful (it includes UAVs processing); you can get freely  the full version but limited to some amount of photos (no more than 15 I think, or no more that some amount of megabytes of data, DEMs, etc). I can´t remember now if it has a monoplotting option,but it is very precise and efficient for traditional photogrammetric processing, also includes satellite imagery processing capabilities. It computes authomatically the tie points using correlation and performs the relative orientation of the photos fastly.

Regarding your question, if you need to test the methodology for oblique photos, I think that the coastal locations are probably the worst scenario (what  is precisely your need). You can test the methodology over cities or places in which you can  accurately measure the coordinates.

I have had good experience processing isolated photos (again, close to vertical) extracted from videos over coastal zones and getting precise planimetric coordinates from high resolution imagery (some GIS commercial software give you access to hi-res satellite imagery when you purchase their software). For the altimetric info I have had good luck with the DEM that I got.

I am speaking of  digital photos with resolution between 50 cm. and 1 meter. Perhaps your coastal oblique photo has 20 cm. or better, for which this kind of satellite sources will be not useful. In any case you need good GCPs...

Hope this helps a bit...

Best regards

Gabriel

Kite are already used for coastal monitoring. You are right, it is an inexpensive method. However, I agree with the previous comment: they are difficult to control and sometimes crash. And if developping, this activity might be regulated.

Coastal monitoring is not only beach monitoring... What about cliffs ?  You can pilot a drone from the top of the cliff, the drone flying at lower altitude than you. This is not possible with a kite.

Moreover, some beaches are surrounding by cliffs and therefore the flight plan of the kite may be restricted...

In my remember the coastal slope concern the inland behind the dune. Because CVI is sea level rise impact oriented, the slope is supposed to take into account the ability of the sea level to submerge the coastal zone. This is the reaseon why cliffs are considered as "safe" to sea level rise and barrriers, salt marshes, deltas... are potentially "very sensitive risk".

Thanks Kenneth. Very helpful paper.

Perhaps it is the interpretation of estuarine that is wrong. The transgression of the Pleistocene glacial termination was very rapid. I published about a lake site in Maine (Borns et al., 2004), Ross Pond, with glaciomarine clays in the bottom 2 m of core, then a narrow (ca 3 cm) pyrite-rich deposit that points to anoxia such as occur in a salinity stratified lake or fjord, then organic rich lake gyttja. The transition from marine to lake occurred within 50 yrs. Other researchers examining late glacial sediments in Maine and New Hampshire (i.e. Belknap and Kelley) have published many papers about offshore transgressive sequences. Perhaps you can find an analogous situation there.

The predominance of rutile over zircon and tourmaline in beach sand sediments occurs when the area of origin consists of high temperature, high pressure igneous rocks, granites, pegmatites and anorthosites. Furthermore, the rutile came from schists, high pressure gneisses and metamorphosed limestones.

Conversely, tourmaline predominates when tourmaline-rich granites and pegmatites or as well as high-temperature hydrothermal veins are present in the area of origin.

The predominant occurrence of zircons points to areas of origin with mafic pegmatites and carbonatites, as well as zirconium-rich igneous and metamorphic rocks.

Dear Colleagues and Friends,

Distance can be measured from image service by using ArcGIS.

Best regard,

V.V. Than

Hi Syed!

I agree with the rest of the respondents that you are in all likelihood dealing with a stromatolitic structure. For the sake of precision, these are produced by microbes (!) not algae, although in earlier days one generally spoke of algal mats. The main culprits, however, are cyanobacteria which, for a long time, used to be erroneously called "blue-green algae", hence the reference to "algal mats". Today one would preferentially speak of "microbial mats". I suggest you get in touch with Nora Noffke (Old Dominion University, USA) who is a world expert on thus structures (e-mail: nnoffke@odu.edu).

Regards, Burg Flemming

Obviously, Malcolm has given a very good and detailed answer and kindly mentioned my paper.

Because rock groynes have voids, they are apriory permeable to water and sediment. Groyne efficiency can often be observed by the elevation differential. This differential was found in the paper to be the main predictor for rate of throughput and this was independent on wave environment, probably just due gravity helped reduced being submerged. There must also be a relationship between void size, void connectivity and sediment size.

One could obviously have a finer core, or have a sheet pile spine within the rock groyne to make it less permeable.

Example of calculation of quatitative parameters of paleoflows using sedimentological data you can see in "Reconstruction of paleohydrodynamic conditions during the formation of Upper Jurassic conglomerates of the Crimean Peninsula"

A. V. Lalomov

Lithology and Mineral Resources 04/2007; 42(3):268-280. DOI:10.1134/S0024490207030066

 A simple model used for different purposes (pdf attached) by the way we have the sandwave as an complete outcrop

The shells are acting as sedimentary particles

The evidence from sedimentary structures and the stratigraphic and biostratinomic context of shell layers are used here to describe how shell beds are formed within a sedimentary sand wave. Shell beds in the Pliocene San Nicola´s Formation,

within the Baja California Central Domain, were accumulated through the physical processes of gravity induced flow currents. The hydraulic regime and sedimentary differences between the up-current slope and the leeward slope part of

the sand wave can be explained by flow stratification. The taphonomic differences between the fossil concentrations of the bottom and the upper layers in the leeward slope are a result of a change in the current dynamics for the basin. The

leeward slope side of the sand wave represents episodic, short-term, dynamic bypassing in gravity-induced, low-flow current beds creating shell beds.

thank you Mr. Van

The real answer depends upon the estimated amount of shoreline change for the are in question.  One to two feet of shoreline change is not detectable within satellite imagery, whereas 30 to 200 feet of change would be.  High resolution aerial imagery is best for electing and measuring small mounts of shoreline change. Also, the precision of the spatial geometry is potentially the most important parameter to be aware of.  If the imagery spectral resolution is 1 meter or less, but the spatial resolution is 3 meters or more (as most satellite imagery is) then you can not be sure that your amount of shoreline change measured is than the spatial resolution. In fact, the estimated error would be double the spatial resolution, meaning the placement of your shoreline will be somewhere within six meters of its location in the image.

Hello Vasudevan -

I am not certain that I understand the question.  Are you saying that you have RMSE estimates and want to know what values went into estimating them?  That would appear to be a problem that has many possible solutions. I mean, the solutions are not unique. Many values could have given the same result.  

Perhaps I do not understand. Could you supply more details for everyone? 

Cheers - Jim 

Hi David, - Risk models and vulnerability assessments and work on the Western Victorian coastline is quite limited, perhaps considering looking at the latest Victorian Coastal Strategy 2014, and the Victorian Coastal Hazard Assessment 2012 for relative citations on coastal process modelling. Hydrology and geomorphology models could assist. 

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.

Have you tried the Global Self-consistent, Hierarchical, High-resolution Geography Database?

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.

The PEEP can use to monitor the real-time change of beachface ?

Well, what you could do is: 1. establish a series of control points along your digitised shorelines, with profile lines perpendicular to the shore at these control points. 2. Use the measure tool in ArcMap to measure the distance between each different epoch (age) shoreline along these profile lines. 3. Divide the measured distance by the time difference for each digitised shoreline. This will give you rates of shoreline change (positive for accretion, and negative for erosion) at each profile/control point location. This is, obviously, the manual way of doing things, and something that I had to do to calculate rates of change for my PhD and is, therefore, something I am very familiar with.

Another method is to use the Digital Shoreline Analysis System - available from: http://woodshole.er.usgs.gov/project-pages/dsas/ . This is a freely available shoreline analysis add-on for ArcMap, which can calculate rates of change statistics for historic shoreline data. I haven't actually used it myself, although I did get as far as downloading one of the older versions, but I would go for this first. You can always try the manual way, if you really want to, at a later date.

Take in mind that water strongly decreases its reflectance when move to the Infrared. If it is not possible for you take NIR or SWIR images, tray at last to “play” with the Red region of the spectrum.  

Dear Dr. Hubert, this is an excellent research paper link which you have provided by Vanhellemont & Ruddick. Precisely what I have been looking for. I have started following your updates. I see that you have also done some work in 'ocean color remote sensing'. Are you still associated with the coastal water study in Hanoi? Thank you so much for your pertinent answer. 

Dear Dr. Mauricio, you have a very keen sense of observation. This is a brilliant idea. Thank you for this first-rate research paper. Those guys in Scripps have been doing some great quality research. I am deeply thankful for your efforts in putting together these significant research papers related to S.California bight and Chile's river plumes. Have you also been doing your research in Chile area?

These are some of the finest answers I've received so far for my question. Since I am just a budding researcher my motivation has always come from being able to observe things by 'standing on the shoulders of giants' like you. Therefore I will be indebted if you have any advice, suggestions or recommendations in order for me to do some quality research which would be beneficial for humans and mother nature alike. Right now I'm at the stage of collecting and examining closely relevant research papers related to remote sensing of coastal regions, all the possible threats which might range from small-scale sand erosion to mighty coastal hazards and the prospect of planning mitigation measures along with analyzing pre and post disaster scenarios for coastal resilience. Conservation of biodiversity in these regions is another area of concern for me.

We sent two interesting cites on the subject:

Lario, Javier; Luque, Luis; Zazo, Cari; Goy, José Luis; Spencer, Chris; Cabero, Ana; Bardají, Teresa; Borja, Francisco; Dabrio, Cristino J.; Civis, Jorge; González-Delgado, J. Ángel; Borja, Tsunami vs. storm surge deposits: a review of the sedimentological and geomorphological records of extreme wave events (EWE) during the Holocene in the Gulf of Cadiz, Spain César; Alonso-Azcárate, Jacinto. Zeitschrift für Geomorphologie, Supplementary Issues, Volume 54, Number 3, July 2010, pp. 301-316(16)

M.A. Rodríguez-Pascua, R. Pérez-López, J.L. Giner-Robles, P.G. Silva, V.H. Garduño-Monroy, K. Reicherter. A comprehensive classification of Earthquake Archaeological Effects (EAE) in archaeoseismology: Application to ancient remains of Roman and Mesoamerican cultures. Quaternary International 242 (2011) 20-30.

C/N ratios of bulk organic matter are cheap and easy to determine with high accuracy. However, the problem is that the C/N ratio of each and every organic matter source varies greatly, and not just with the tissue type of the source material (there is great differences in the C/N ratio between woody tissues and leaf tissue of the very same tree, for example) but also with the level of organic matter degradation. In a forest, the leaf litter on the ground may have C/N ratios between 20 and 30. In the underlying topsoil the ratios will have dropped to values between 10 and 20. Degraded organic matter in some clay-rich tropical soils (e.g. oxisols) can have C/N ratios down to 8. Litter and soil are already two potential end-members on the terrestrial side with great ranges in their individual C/N ratio. Plants from the littoral zone have variable C/N ratios, bacterial biomass has very low C/N ratios (~4) etc. ...

As you already recognised yourself there is a great range of sources, definitely more than three, and organic matter degradation will just add further variability. It depends on your study site. In some settings, where long-distance transport processes have averaged out the details, C/N ratios may well work to identify, for example, phases of generally higher or lower terrestrial input. However, using C/N ratios to disentangle contributions from anything more specific than the usual aquatic vs. terrestrial organic matter sources, I'm afraid, this won't work. This requires a multi-proxy study and organic-geochemical fingerprinting of the potential organic matter sources in your study area. Isotopes are a good start and biomarkers are very useful, too.

Hope this helps.

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.

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

I am quite late but here are some explanations about the Tait equation. It was established in the 19th century according to experimental results on sea water. The gamma coefficient has nothing to do with some volume weight. It is only a coefficient used to get close to experimental results. Trying to use this equation of state with sand and/or soil seems to be out of its domain of use.

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

Amr Saleem,

I was wondering if you were looking for an image processing system, in such case the answer depends very much on the dataset you are going to use. Automated recognition from single images isn't working perfectly as yet in gavel environments.

I drilled lots of meander cutoffs for my PhD with a 100mm diameter commercially available hand auger set. Different auger heads are available for both sandy sediments and for more clayey sediments. In my meander cutoffs which had filled with a silt-clay plug, I used the 'soil' auger head until I reached the sandier former bedload sediments at depth where I switched to the 'sand suger' head. It is easy to extract sediment samples at 5-10 cm intervals from the auger heads with a dinner knife and collect the sediments in plastic bags for laboratory processing. Attached is a book chapter that outlines some of this work - hope this helps!

Dear Filippo, you are talking about very different tools and as all numerical models there is not the "medicine for all illnesses". First of all, you must realize that none of the tools available at the moment can cope with a 10 year simulation over 25 km of coastline! For sure it is not very feasbile with 2-d or 3-d computational domains, where even building a grid over 25 km would make you miss all coastal features, unless you have a 25 km straight coastline, which I doubt. Over such a space you are forced to work in 1-d mode and for this I think Xbeach is far better that other models at least for dune-beach erosion. The fact is that to run 10 years of waves will not be easy, unless you play around a lot with time-scaling, which may make the mode unstable. If the 10 years of waves means instead a wave climate representative of those 10 years, that is a different thing. I hope it helps

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

You can build a polygon of the shape of your study area and measure the area of this polygon. If you measure the area over time, you can obtain the quantitative change over time.