There is no simple relationship.

It depends on the mobility number of the sand grains. This mobility number is a function of the amplitude of the wave, and its pulsation.

Have a look on Chapter 10 "Sediment Transport and Morphodynamics in Nearshore Ares" in the book "Erosion of Geomaterials" (link below).

Book Erosion of Geomaterials

Thank you so much for comment and suggestion. But, is there a less complicated relationship between sand grains and inclination of beaches?

You can find at following link a very good article about beach systems, and among other things you can find some answers related to your questions:

http://geology.uprm.edu/Morelock/beachsys.htm

Also, I can recommend you a very good paper of Malvarez et al. (2001), in which you can also find some answers to your question. Here is the link:

http://web.upo.es/export/portal/com/bin/portal/upo/profesores/gcmalgar/profesor/1252488421238_sedp_71_05_0705.pdf

I hope that I helped you at least a bit with provided literature! Good luck in your further research!

Thank you so much, Stanislav Franciskovic-Bilinski. I think literature from your advice

very useful for me.

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

Thank you so much, Burghard Flemming!

Dear Tran Thanh,

just go to the book "Brown, J. et al., 2005. Waves, tides and shallow-water processes; 227 pp. (open university press). It is easy to read an gives good examples.

There is a very nice example of the influence of grain-size and wave energy on beach slope in the classical book of P.D. Komar (1998) "Beach Processes and Sedimentation". Have a look at Fig. 7-16, based on Bascom (1951) and Wiegel (1964)), which shows very clearly the influence of grain-size and wave energy on beach face slope.