Its a bit appropriate, but if you want to receive more result, I would recommend "Reverb". Firs you can register and than download ASTER images according various dates. For erosion study its will be more suitable than Google Earth.

You can see next link: http://reverb.echo.nasa.gov/reverb/#utf8=%E2%9C%93&spatial_map=satellite&spatial_type=rectangle

Also, you can use "earthexplorer", its also free, after register you can download Landsat aerial images. See next link: http://earthexplorer.usgs.gov/

After than you can use GIS, or ENVI, or other suitable program.

Actually yes since it gives you the coastline position and the date of the image, but you have to understand the limitations of the satellite imagery. One of them is the inability to show the very steep cliffs due to hanging of the upper soil layers above the lower ones.

Yes, definitely. However, you may not get latest satellite images of your study area.

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..

http://earthobservatory.nasa.gov/Features/WorldOfChange/cape_cod.php

Yes but Google earth  image may not support some analysis using standard image processing software. 

Thank you all.  It is really helpful.

Absolutely no! Accuracy is genery lower the erosion/accretion yearly rate. You cannot correct for tide, unless you have tide measures at the overflyght time and beach slope. But if you must go on the field to measure beach slope you can survay the shoreline, which is the zero meter contour, not any other indicator, e.g. litter line, vedetation line. I can give you references if you need. Cheers, Enzo

…in fact it is depending of what you are looking for and the order of magnitude of shoreline changes. On pocket and stable beaches (shoreline change 10m/yr) it could be accurate. But you have to correct the images by GIS procedures (orthorectification). You cannot directly use GoogleEarth to quantify shoreline changes. It is appropriate to describe coastal feature and qualitative evolution (not so bad at all !).

 Dr. Enzo

I would be grateful if you would kindly send me the references 

Be aware that registration may lead to problems in accuracy. That's my biggest caveat. We've seen some very interesting registration errors with Google Maps and Google Earth overhead imagery that presented problems for us.

Yes, it is possible with results achieved. Everything depends on the magnitude of erosion and sedimentation processes. If these are large-scale (greater than 3 meters per year), good results were achieved, but not in those shores where the amount is less, as it would be in the order of the error of the picture and changes the amplitude of the tides, element to keep in mind.

Sure, google images preprocessing lead out but there are several videos on youtube that explain how to do it.

Best wishes

Yes, it is possible with results achieved. Everything depends on the magnitude of erosion and sedimentation processes. If these are large-scale (greater than 3 meters per year), good results were achieved, but not in those shores where the amount is less, as it would be in the order of the error of the picture and changes the amplitude of the tides, element to keep in mind.

Sure, google images preprocessing lead out but there are several videos on youtube that explain how to do it.

Best wishes

 Dear all thanks and Thanks Levan Tielidze ,

My question,  NASA Earth Explorer (EE) offers Aerial imagery all over the worlds! or only it offers satellite images such as Landsat archive? 

With Google Earth you can make a diagnosis in the short term. About 10 to 15 years.

If you want to do it long term will have to resort to other sources generated by other institutions. Especially if what you want is to quantify the evolution observed.

One more suggestion for imagery source. I could also try SAR Sentinel 1 data offered by ESA. It needs more processing, but will offer 0.5m resolution. For historical data one may refer to ERS1/2. 

Hi, Nalin and everybody!

After reading all the answers in this topic, and stating the variability of these anwers, I think that your first step should be to construct a methodological approach to your analysis.

You will probabaly have to define what property of coastal erosion you want to analyze, the extent of your analysis and the scale of details that you need to get in your results.

Only after defining your initial methodological approach, you will know if it is possible or not to use Google Earth data in your analysis, taking in mind the constraints that Enzo and others cited in this forum.

I believe that Google Earth may help you at least to spot some erosion occurrences in your study area, but I am not sure if you are going to spot ALL erosion occurrences, because there may be many places where the data is not available with the repetition you would need to assess it.

But I can say that in order to quantify soil erosion, you would need to have very detailed data to get good results, and they must be orthorrectified, as someone mentioned before.

Nevertheless, if your analysis approach fits a coarse-30 m resolution dataset, I would tell you to try programming in Google Engine, so that you could use the complete Landsat series dataset that they had stored in their database.

Sorry for answering so late. Look at this book.

http://www.beachmed.it/Portals/0/SOUSPROJETS/2_1%20OPTIMAL/BeachErosion%20lowres.pdf

Pag 51 - 60 has some specific considerations on shoreline extraction from satellite images.

Regards, Enzo

As stated above, it depends on the magnitude of erosion, but is also important date image, since the effect of a temporary may be misleading in evaluating erosion. At the end of the day, it can be understood as the result of sediment exchange between submerged beach side beach and air transport in the medium term.

Personally I think it is OK as long as you know the features (spatial, spectral, temporal, and radiometric resolutions) of these images, so other people can repeat your work.

How exactly may one carry out rectification of images obtained from Google Earth for Remote Sensing studies?

I think both James Varghese and François Sabatier have answered your question perfectly. Google Earth can be a useful tool in studies of coastal erosion, but taking into account the type of study to be carried out (the coastal erosion processes are much more complex than the simple fact of the coastline retreat in several years) Resolution of work and correction of the images.

hi

its better to use aerienn image , with very good precision and with high resolution.

Good luck

HoW an you correct for tide? Not only astronimical but also baric; and the apply correction considering swashzone slope (which cannot be retrieved by images).

Go to the beach with due instruments! It's more accurate and ... amusing!

In my opinion it is not appropriate to remain only on Google Earth images to quantify shoreline changes / to study the coastal erosion / measurements of shoreline change rates. With Google earth images you may use the tool Historical imagery (using the time slider to move between acquisition dates – the seventh “clock” icon). Aerial photography is also useful tool for the analysis. In Montenegro we communicate with the Real estate Agency for some of the aerial photographs. In some cases the simple topographical (army) maps from the previous century (centuries – Austro-Hungarian maps) in the Balkans – this part of Mediterranean, may also be useful. We use the old maps to analyse the evolution of some lakes in Montenegro. On top of it you may include in the analysis the approach of repeat photography to record the changes. See some examples on: (1) Repeat Photography Collections for Sustainability and Working Forests); (2) Using Repeat Photography to Capture Landscape Change; (3) Repeat Photography Project (U.S. Geological Survey); (4) See also: Nyssen, J., Van den Branden, J., Spalevic, V., Frankl, A., Vandevelde, L., Curovic, M., Billi, P., 2014. Twentieth century land resilience in Montenegro and consequent hydrological response. Land Degradation and Development, 25: 336–349.

Using the instruments, as recommended by Professor Enzo Pranzini, is correct for the current status. (more accurate as he stated). But the time machine is with the Google earth images, Repeat Photography Collections, old Army maps, Old Aerial photographs…

I think it can be quite useful to use google earth images as background when drawing. It is definitely better to use an ortho-photo if available

I think it is better to use sattalite images with high resolution than google earth images if available.

i think google earth can be your first step. Using the time-line tool you can observe hotspots areas of interest. Then, I think you can rather use images like Worldview 2 or Iconos, if possible (they can be expensive). Anyway, I think it is better than use Landsat, which has a 30m pixel size. We know coastal changes within a decadal scale comonly don't go further..

It is better to use an ortho-photo if available, but it is possible to use high resolution images from google earth when have earth control points, to make a good rectification and referencing of images, particularly on micro-tidal beaches.

Check the link https://www.researchgate.net/publication/339364264_Erosion_of_Carbonate_Beaches_on_the_Northeastern_Coast_of_Cuba

Thanks to the very dense temporal sequences that Google Earth offers, I have used it as a tool to locate and date mass movements in low-middle cliffs that I have subsequently mapped in correctly projected and georeferenced orthoimages.