Abstract
A dynamic equilibrium bay (DEB) is an embayment with continuous sediment supply and its shoreline planform can remain stable over a long period of time without erosion or accretion. For coastal conservation of sandy headland-bay beaches (HBB), the concept of using a static equilibrium bay (SEB) is well known, but that for DEB has received little attention. Moreover, an empirical equation for the stability of a DEB is not yet available. Experiments on DEB shape that aim to derive new coefficients in the parabolic bay shape equation (PBSE) for DEB are now being conducted in the laboratory. The work commences from an initial artificial HBB in static equilibrium with sediment supply source from the lee of an upcoast headland. A final equilibrium planform is obtained for the condition with a specific wave obliquity and sediment supply rate until no further shoreline change is found. In order to fit the PBSE for a DEB, a new parameter called SSR (sediment supply ratio) that represents the ratio of sediment supply rate from the source and the potential longshore sediment transport rate is introduced to quantify the balance of sediment to the bay. Alternative C coefficients in the PBSE for DEB, which include wave obliquity and the SSR, are then calculated. These new coefficients for DEB can now be used to evaluate the influence of sediment supply from a riverine source on a DEB and to classify its equilibrium status for planning sediment management strategies in coastal conservation.
Similar content being viewed by others
References
Chatchai P (2005) Experimental study on development of dynamic bay shape. Thesis, Asian Institute of Technology
Ho SK (1971) Crenulate shaped bay. Thesis, Asian Institute of Technology
Hsu JRC, Evans C (1989) Parabolic bay shapes and applications. Proc Inst Civil Eng Part 2 87:557–570
Hsu JRC, Yu MJ, Lee FC, Benedet L (2010) Static bay beach concept for scientists and engineers: a review. Coast Eng 57:76–91
Kamphuis JW (1991) Alongshore sediment transport rate. J Waterw Port Coast Ocean Eng 117:624–640
Khoa VA (1995) Experimentation on bayed beaches between headlands for small wave angle. Thesis, Asian Institute of Technology
Klein AHF, Vargas A, Raabe ALA, Hsu JRC (2003) Visual assessment of bayed beach stability with computer software. Comput Geosci 29:1249–1257
Kraus NC, Harikai S (1983) Numerical model of the shoreline change at Oarai Beach. Coast Eng 7:1–28
Krumbein WC (1944) Shore processes and sedimentation. Mem. No. 3
Moreno LJ, Kraus NC (1999) Equilibrium shape of headland-bay beaches for engineering design. Proc Coast Sediments ’99 2:844–859
Silvester R (1960) Stabilization of sedimentary coastlines. Nat Public Group 188:467–469
Silvester R, Hsu JRC (1993) Coastal stabilization : innovative concepts. Prentice-Hall, NJ
Silvester R, Hsu JRC (1997) Coastal stabilization. World Scientific, Singapore (Reprint of Silvester R, Hsu JRC, 1993)
Somruthai T, Sutat W, Babel MS, Clemente RS, Noppadol P (2014) Equilibrium of Crenulated Bays in Thailand. Coast Eng J 56(4):
Tan SK, Chiew YM (1993) Bayed beaches in dynamic equilibrium. Adv Hydro-Sci Eng I : 1737–1742
Tan SK, Chiew YM (1994) Analysis of bayed beaches in static equilibrium. J Waterw Port Coast Ocean Eng 120:145–153
Vichetpan N (1969) Equilibrium shapes of coastline in plan. Thesis, Asian Institute of Technology
Vithana HPV, Weesakul S, Gunasinghe AASK (2000) Sand spit formation in a simulated river mouth. Proc 27th Int Conf Coast Eng : 3817–3828
Xiam VD (2004) Development of dynamic bay shape. Thesis, Asian Institute of Technology
Yasso WE (1965) Plan geometry of headland-bay beaches. J Geol 73:702–714
Yu MMJ, Hsu JRC (2006) Parabolic bay shape equation revisited for practical applications. Proc ICCE Coast Eng II: 3478–3490
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Tasaduak, S., Weesakul, S. Experimental study on dynamic equilibrium of headland-bay beaches. J Coast Conserv 20, 165–174 (2016). https://doi.org/10.1007/s11852-016-0427-y
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11852-016-0427-y