Content Research

Chinese Journal of Oceanology and Limnology

Vol. 27 No. 3, P. 683-696, 2009

DOI: 10.1007/s00343-009-9124-0

Characteristics of modern sedimentation in Qingdao bays*

CHEN Zhengxin,, Paul Huang, HUANG Haiyan,,

DONG Heping,, LI Shaoquan,, LI Chun,

Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology, Ministry of Land and Resources, Qingdao,

266071, China

Qingdao Institute of Marine Geology, Qingdao 266071, China

Faculty of Science, University of Alberta, Edmonton, Alberta, Canada

Received May 29, 2008; revision accepted July 24, 2008

Abstract With available survey data and 237surface sediment samples, the modern sedimentation in

Qingdao bays is studied. The research result shows that the east area is shallower (16.4 m) than that in the

west (45.8 m). The geography was formed by a symmetric wave in a sequence of bank offshore

depression platform tidal channel platform offshore depression foreshore from south to north.

Flood sedimentary systems were formed from inlet of the Jiaozhou Bay in the west to the barrier bar in

the east. Lateral sedimentation includes mainly tidal current ridges in two tidal channels. Gravel sandy

sediments formed by wave lie in midland of from seashore to wave base. Dynamic functions are mainly

tide and wave. Tidal current moves sediment in vertical and horizontal directions, sorting sediments and

providing materials for coastwise beaches. The sources of sediment are mainly from eroded headland

rocks. In general, grain sizes in this area from the inlet of the Jiaozhou Bay in the west (120 17 ) to the

barrier bar outside in the east (120 35 ) are coarse-fine-coarse, forming gravel-gravelly sand (G-S), sand

(S), gravel clay silt (G-YT), clay silt (YT), gravelly silty sand (G-TS), silty sand (TS), gravelly sandy silt

(G-ST), and sandy silt (ST) in turn.

Keyword: Qingdao bays, surface sediments, tidal current ridges, sedimentary dynamics

1 INTRODUCTION regions rather then the entire system of the bays.

As the outcome of project of the 1:50 000 Environ-

Qingdao bays are referred to those located in

mental Geological Survey and Assessment of Qing-

Qingdao in the western edge of middle Yellow Sea,

dao (2002 2004) and Geological Environmental

China, with Jiaozhou Bay to the west. The research

Quality Evaluation and Sustainable Developments of

region is a semi-closed shallow coast, connecting

Ecology & Economy of Qingdao (2003 2005), the

Tuandao in the west (120 17 E), Shazikou in the east

source, distribution, and characteristic of sediments,

(120 35 E), Haixi Peninsula in the south (35 58 N)

hydrodynamic processes, and tidal sand ridges in

and Qingdao City in the north (36 06 N) (Fig.1). The

Qingdao bays are discussed in detail in this article.

research area is about 30 km long east-west, and

The waves are seasonal with wind changes. In

5 15 km wide south-north with an area of about winter, waves are mainly in direction of NWW-

400 km2. The maximum water depth is 45.8 m NNW, of which 18% is in NW, and 7% NNW; in

(120 17 25 E 36 01 45 N). There is no longer large spring the wind waves is in E (14%) and SEE (9%);

river freshwater input except for seasonal runoffs in summer ES is the main wind direction, and 12%

from several creeks and some sewage channels. are in E and 9% in SEE. and in fall the frequency of

Coastal studies in Qingdao dates back to the NW wave is 10%. The ground swell is in EW to SW.

1960 s. Large-scale research initiated in the 1980 s, SE is the most frequent direction swell for taking

and mostly in the Jiaozhou Bay in hydrology, 26% of the total in a year (Table 1). The annual mean

sedimentation, topography, and environment, few in wave height is 0.7 m. Wave height increases

Qingdao bays, especially on sedimentation. Liu et al.

(2004), Yu et al. (2003) and Wang et al. (2000) Supported by the National Natural Scientific Foundation of China (No.

studied the tidal and sedimentary characteristics in 40506013).

Corresponding author: abplju@r.postjobfree.com

Qingdao bays, but these studies are on limited

CHIN. J. OCEANOL. LIMNOL., 27(3), 2009 Vol.27

684

Fig.1 Location map of samples

Table 1 The average seasonal Stormy wave distribution in Qingdao bays *

Month N NNE NE NEE E SEE SE SSE S SSW SW SWW W NWW NW NNW

Jan. 1 1 1 1 5 2 0 1 2 4 5 1 2 7 18 7

Apr. 1 1 1 2 14 9 4 3 5 4 3 0 1 2 7 4

Jul. 0 0 1 2 12 9 6 5 3 2 1 1 1 1 2 0

Oct. 3 2 2 1 6 7 6 5 6 8 4 1 2 3 10 4

*1:50,000 Environmental Geological Survey and Assessment of Qingdao (2002 2004)

gradually in the first half of a year and reaches the coast in the front of the bay; while circle tidal

maximum of 0.9 m in July. In the second half of year, currents occur inside the bay. Flood tide current is

the wave height decreases gradually to the minimum clockwise and ebb tide is anticlockwise in the bay.

The rock in Qingdao bays is mainly the Mesozoic

of 0.5 m in January and December.

granite, and some volcanic assemblages. Breccia tuff

The tide in Qingdao bays is a normal semidiurnal

and volcanic silication zone outcrop near Shilaoren

tide. The mean tidal level, tidal size and tidal

(Stoneman) beach. Faults are mainly developed in

dispersion measured in Maidao Station are listed in

NE-NNE as the controlling factor over the structural

Table 2. The interval of flood tides is 1 hour shorter

and geomorphological patterns, including Cangkou

than that of ebb tides. The flood tide current is

Fault, Licun-Fulongshan Fault, Qingdaoshan Fault,

westward and the ebb tide current eastward in all

Guanshan Fault, and Taipingwan Fault. Qingdao

small bays. The maximum flood tide current appears

bays were resulted from the Holocene transgression,

usually 1 hour before the highest tide and the

and is a stable area of steady uplifting in tectonics.

maximum ebb current 1 hour after the lowest. The

There is only one marine layer of the middle-late

turning of tidal current appears 2 hours after the

Holocene in age, which covers the late Pleistocene

highest tide. To-and-fro tidal currents occur near

fluvial or diluvial deposits. In the west tidal trough of

the research area rocks outcrop.

Table 2 Mean tidal level, tidal size and tidal dispersion in

3 METHODS OF SAMPLING AND

Maidao Station*

ANALYSIS

Mean high tide Mean low tide Mean tide range

Item

(m) (m) (m)

3.1 Sampling

Spring tides 4.18 0.76 3.42

Neap 3.08 1.31 1.77

In 2002 and 2005, 237 surface sediment samples

*1:50 000 Environmental Geological Survey and Assessment of Qingdao

were taken in Qingdao bays in a grid of 1 km 1 km

(2002 2004)

No.3 CHEN et al.: Characteristics of modern sedimentation in Qingdao bays 685

4 RESULTS AND DISCUSSION

(Fig.1) in four cruises, and analyzed in grain size

distribution. The total length of shallow seism

4.1 Geomorphology and topography

profiles is 520 km and that of multibeam measure is

The coast of Qingdao is made of rocky and sandy

600 km.

Box sampler (0.04 m3) and clam snapper (0.01 m3) clastics. Beakheads distribute separately with bays in

between. The beakheads protrude toward the sea,

were used for sampling. Sediments from the upper

which are Tuandao, Xiaoqingdao, Huiquanjiao,

0 5 cm were taken as surface samples.

Taipingjiao, Yan erdao, Maidao and Shilaoren from

DGPS positioning system was used in positioning

the west to the east, and the bays are Tuandao Bay,

with an error of 2 mm) was landform is flat in every bay. The gradient of sea

sieved, and the fine fraction was collected and bottom is flat from the Park of Sculptures to

analyzed with a Laser Grain-size Analyzer, Shilaoren beakhead. There are three geography types

Mastersizer 2000 produced by MALVERN Corp. of sea-bottom in this region: tidal current ridges, tidal

United Kingdom. Sediments were separated in the channel, and tidal flat.

interval of 1/4 . The geomorphology of the sea bottom is

All samples were analyzed in the Qingdao Test characterized by separately distributed tidal channel

Center for Marine Geology of Chinese Geological (depression) and highland (or sand ridge, Fig.2) from

Survey. south to north. Two sides of the ridges in tidal

Fig.2 Transection of the major tidal channel

a. A-A section; b. B-B section; c. C-C section; d. D-D section; e. E-E section

CHIN. J. OCEANOL. LIMNOL., 27(3), 2009 Vol.27

686

276 cm/s; surface tide speed is 150 cm/s. In the sea

channel are generally in east-west and are called

area south of Maidao, the surface flood tide speed is

respectively the Southern Sand Ridge (SSR) and

80cm/s; the ebb tidal current speed is 100 cm/s.

the Northern Sand Ridge (NSR) . The NSR starts

from east of Tuandao (120 17 E), to east of 120 25 E, Moreover, the measured surface flood tidal current in

the northern secondary channel is 76 cm/s (possible

and disappears after entering the vast sea area.

greatest value 109 cm/s); surface ebb tidal current is

Despite an interrupt in the eastern Taiping Bay (Fig.

72 cm/s. Therefore, the flood current speed is

2c.), it is continuous in overall. The NSR is roughly

generally greater than ebb current speed at the

12 km long east-west, and 2 km wide (Fig.13) and the

opening of the bay, the speed in lower level is greater

water depth above the ridge is 11 16 m. The ridge is

than that at the surface. The speed is generally high.

10m above the bottom nearby, and steeper in the

East of 120 20, the ebb tidal current is greater than

north and gentler in the south (Fig.2a, b, d, e). The

SSR is in the south of the tide channel from 120 19 flood. From the area south of Shazikou, the tide turns

to 120 25 in over direction of 110 (SEE). With an back to normal Yellow Sea tide.

interrupt at 120 21 it is generally continuous, too. It According to the data recorded between 1956

1981 in Xiaomaidao Tide-Wave Station, the

is 10 m above the sea bottom around and it is steeper

dominant waves are in three directions, E, SEE, and

in both sides and gentler in the middle (Fig.2b,d).

SE. The average wave height of the E wave is 310 cm,

The widest part is roughly 5.5 km, and roughly

with the maximum wave height 960 cm (frequency

9.6km long (Fig.2b, d, Fig.13).

0.1), and the minimum height of 210 cm (frequency

In 110 eastward is a long low land in Jiaozhou

99). The average wave period is 7.0 s; the average

Bay called the Tidal Channel (TC) . It is gentler and

wave height of the SEE waves is 335 cm, with the

wider in the middle part, and steeper in two sides

maximum wave height 1 460 cm (frequency 0.01)

(Fig.2). The width of the sea bottom is 1.3 km within

and the minimum 220 cm (frequency >95). The

40 m isobath (Fig.1). The deepest point is 45.8 m at

average wave period is 7.7 s; the average wave

the opening of Jiaozhou Bay. The TC extends to the

outside area of Fushan Bay (120 22 ) and gradually height of the SE waves is 320 cm, with the maximum

wave height 1 590 cm (frequency 0.01) and the

disappears eastward in deeper water, changing to

minimum 230 cm (frequency >90). The average

normal phase sea bottom topology.

wave period is 7.9 s. The maximum wind current

Tidal-flat sedimentary topology is seen south of

speed is 82 cm/s. When the wind current is in the

Maidao, and becomes gradually higher eastward.

direction of the tidal current, the speed can reach

The maximum water depth in the middle is only 16.4

140 cm/s (Chen et al., 2006).

m. This area slopes off slowly eastward and

westward, and the width is 15 km.

4.3 Type and distribution of sediments

There is a long oval depression from Taipingjiao

The sediments in the research area are divided into

to Chidao in the north of NSR, called the north

five grain-size types in the Shepard s classification.

secondary tidal channel. It is 9 km long east-west and

The concept of gravel is added to this classification

1.5 2.2 km wide north-south. The shallow area near

in this study to better describer the characteristic of

shore northward to 10m-water depth is called

sediments in this area. Although the content of gravel

seashore intertidal zone and the isolines parallel to

is not further subdivided and marked as prefix G-

the coastal line in east-west. In the south of SSR, no

only, it is described quantitatively in different types

secondary tidal channel is developed, except for an

of sediments. They are gravels (I), gravelly sand

under-developed narrow seashore intertidal zone.

(G-S) and sand (S)(II), gravelly silty sand (G-TS) and

4.2 Dynamics

T he tidal type in research area is normal

semidiurnal. Two sets of flood tides and ebb tides

develop in one solar day. A measurement in 1999

shows that in the east of research area, under normal

sea condition, the tide rate normally range 26

41 cm/s and occasionally to 58 cm/s (maximum). Liu

(2004) found that the maximum speed in the middle

Fig.3 Sand ridge to the south of the tidal channel

layer during ebb tide occurs at the narrowest bay Head(N)of seism section: 36 00 N, 120 22 E;

opening at 241 cm/s, and that during flood tide is End(S): 35 59 N, 120 22 E

No.3 CHEN et al.: Characteristics of modern sedimentation in Qingdao bays 687

Type V gravelly clay silt (G-YT) and clay silt (YT)

silty sand (TS)(III), gravelly sandy silt (G-ST)and

appears mainly in the middle area of tidal channel in

sandy silt (ST)(IV), gravelly clay silt (G-YT) and

water depth of 23 35 m, in the inshore zone from the

clay silt (YT)(V)(Fig.5).

south of Maidao to the east coast of Shilaoren in 6 15

Type I gravel area (I): Almost no accumulation but

m, and to the south of Shazikou.

only a limited detritus and small rocks with some

bio-fragments are present, and distributed within

4.4 Grain size of sediment components

40 m isobath west of research region. The grains are

Characteristic detritus and gravels are seen in the

mainly from angles or sub-angles, and sub-round to

center of the opening of Jiaozhou Bay west of the

round (Fig.5).

research area. The gravel percentage is 15.2% 100%.

Type II gravelly sand (G-S) and sand(S)

Grain size distribution of gravel and gravel sand in

distributes in the east of Type I area, the northern

the east of the opening is mainly in single mode and

shore of the Haixi Peninsula, the Zhuchadao Bay, the

positive skewness (Fig.6a), mostly poorly sorted.

beakheads and nearby beaches. They are in patch and

The sorting coefficients ranges from 0.33 (well

zone in distribution pattern (Fig.5).

sorted) to 3.08 (very poorly sorted), and main

Type III gravelly silty sand (G-TS) and the silty

component features leaping movement.

sand (TS) distributes widely. They are the common

Gravel sands in seashore area less than 15m

sediments in the research area mainly in the central

contain 0.2% 2.53% gravel content and 84.33%

part, in the area to the south of Shazikou, and in the

96.05% sands. The grain size distribution is mainly

tidal zones of small bays, in water depth of 16 22 m

in single mode with positive skewness (Fig.6b). The

(Fig.5).

sorting is in overall poor with the sorting coefficients

Type IV gravelly sandy silt (G-ST) and sandy silt

ranging from 0.79 (moderately sorted) to 2.14 (very

(ST) distributes mainly in the east of the tidal channel

poorly sorted), reflecting the influence of wave. The

in NW-SE and the south of central tidal channel in

gravel content in gravelly silty sand and the silty

east-west (Fig.5).

Fig.4 A transection of the area from the east to the west

Head of seism section(W): 36 00 N, 120 20 E; End(E): 36 00 N, 120 26 E.

Fig.5 The distribution of sediments in the research area

CHIN. J. OCEANOL. LIMNOL., 27(3), 2009 Vol.27

688

Fig.6 Grain size distribution of selected samples

a. 36 1.87 N, 120 18.33 E; b. 36 5.06 N, 120 27.68 E; c. 36 0.79 N, 120 29.68 E; d. 35 59.7 N, 120 24.34 E; e. 36 2.41 N; 120 20.33 E; f.

36 2.95 N, 120 25.67 E

In the gravelly sandy silts and sandy silts area the

sand in central tidal trough is from 2.53% to 5%

content of gravels varies 0.1% 1.83%, while that of

while the content of sands is 54.33% 76.05%, silts

silts, 38.37% 63.37% in average of 53.52%, sands

18.33 38.05%, and clay less than 15%. The grain

19.41% 40.46% in average of 28.12%, and clays

size distribution is mainly in single mode with

11.47% 21.15% in average of 17.15%. The sorting

positive skewness (Fig.6c, e). On the accumulation

coefficients are 1.87 3.84, the poorly to the worst

chart, Fine component grain shows suspended

poorly sorting. The probability curves have both

movement in double suspension state. The sorting is

singlet and split-blip, both positive and negative

poor and the sorting coefficients ranges from 0.48 to

skewness. The shape of the curves is sharp or broad.

2.77 in a series from good satisfactory moderate

Sometimes sharp and broad peaks are both present in

poor very poor, indicating influence of two-

a given sample. (Fig.6d).

direction wave movement.

No.3 CHEN et al.: Characteristics of modern sedimentation in Qingdao bays 689

Fig.7 The distribution of the mean grain size (Mz)

ridge, the wave energy is consumed, the sediments

In the gravelly clay silts and clay silts area, the

are re-suspended, and then settle down in a low

content of clays is 1.27% 32.62% in average of

energy water environment at the rear of the sand

21.53%, while that of the gravels

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