Study on headland-bay sandy coast stability in South China coasts |
| |
Authors: | Ji-tao Yu Zi-shen Chen |
| |
Institution: | YU Ji-tao and CHEN Zi-shen 1 Department of Water Resources and Environment,Geography and Planning School,Sun Yat-sen University,Guangzhou 510275,China |
| |
Abstract: | Headland-bay beach equilibrium planform has been a crucial problem abroad to long-term sandy beach evolution and stabilization,
extensively applied to forecast long-term coastal erosion evolvement and the influences of coastal engineering as well as
long-term coastal management and protection. However, little concern focuses on this in China. The parabolic relationship
is the most widely used empirical relationship for determining the static equilibrium shape of headland-bay beaches. This
paper utilizes the relation to predict and classify 31 headland-bay beaches and concludes that these bays cannot achieve the
ultimate static equilibrium planform in South China. The empirical bay equation can morphologically estimate beach stabilization
state, but it is just a referential predictable means and is difficult to evaluate headland-bay shoreline movements in years
and decades. By using Digital Shoreline Analysis System suggested by USGS, the rates of shoreline recession and accretion
of these different headland-bay beaches are quantitatively calculated from 1990 to 2000. The conclusions of this paper include
that (a) most of these 31 bays maintain relatively stable and the rates of erosion and accretion are relatively large with
the impact of man-made constructions on estuarine within these bays from 1990 to 2000; (b) two bays, Haimen Bay and Hailingshan
Bay, originally in the quasi-static equilibrium planform determined by the parabolic bay shape equation, have been unstable
by the influence of coastal engineering; and (c) these 31 bays have different recession and accretion characters occurring
in some bays and some segments. On the one hand, some bays totally exhibit accretion, but some bays show erosion on the whole.
Shanwei Bay, Houmen Bay, Pinghai Bay and Yazhou Bay have the similar planforms, characterized by less accretion on the sheltering
segment and bigger accretion on the transitional and tangential segments. On the other hand, different segments of some bays
have two dissimilar evolvement characters. Dacheng Bay, Shenquan Bay, Hudong Bay, Wukan Bay, Fengjia Bay, Wuchang Bay, Lingshui
Bay and Tufu Bay produce accretion on the tangential segment, erosion on the transitional segment and accretion on the sheltering
segment. However, Guang’ao Bay, Haimen Bay, Jinghai Bay, Sanya Bay(a), Dajiao Bay, Hailingshan Bay, Hebei Bay, Fuhu Bay, Shuidong
Bay, Wangcun Bay and Bomao Bay generate erosion on the tangential part, accretion on the transitional part and accretion on
the sheltering part. It seems to imply some relations between headland-bay beach evolvement and controls on headland-bay beaches,
which may possibly to classify headland-bay beach types and should be further studied. |
| |
Keywords: | Headland-bay beaches parabolic bay shape equation digital shoreline analysis system end point rate |
本文献已被 CNKI 万方数据 SpringerLink 等数据库收录! |
| 点击此处可从《中国海洋工程》浏览原始摘要信息 |
| 点击此处可从《中国海洋工程》下载免费的PDF全文 |
|