The Bohai Strait, located at the Laotieshan Cape at the southern end of Dalian, Liaoning Province, China, andShandong ProvinceBetween Shandong PeninsulaYellow Sea、the bohai seaThe strait ofthe bohai seaIt is the only outlet of the Bohai Sea, so it is called the "throat of the Bohai Sea".The Bohai Strait is 105 kilometers wide from south to north, and Miaodao Islands (belonging to Yantai, Shandong Province) is the main island in the Strait.
The Bohai Strait is located in the transitional zone between the Bohai Sea fishing ground and the Yellow Sea fishing ground. Small yellow croaker is the main fishing resource in the history of the Bohai Strait and the fishing base of Liaoning and Shandong provinces.
Since the west side of the Bohai Sea is the capital of China, Beijing, and Tianjin, an important industrial town, it is also known as the "Beijing Tianjin Gateway", and is a strategic area for coastal defense in northern China.[1]
It has always been the focus of military strategists.At the beginning of the Tang Dynasty, an important defense town was set up on the Miaodao Islands.In the Qing Dynasty, the British and French allied forces successively occupied Beijing and Tianjin through the Bohai Strait three times.The Eight Power Allied Forces also captured Beijing and Tianjin via the Bohai Strait.After the founding of the People's Republic of China, Long Island became a fortress area.Border guards are stationed at both ends of the strait.[2]
Chinese name
Bohai Strait
Foreign name
Bohai Strait，Bohai Haixia
Geographic location
Between Bohai Sea and Yellow Sea, between Liaodong Peninsula and Shandong Peninsula
Bohai StraitShandong Peninsula AndLiaodong PeninsulaIt is the boundary between the Bohai Sea and the Yellow Sea.The width (from south to north) is 57 nautical miles (105 km), and the width from east to west has no reference data.[3]According to the Chronicles of Shandong Province, the Bohai Sea can be divided into five parts: Liaodong Bay, Bohai Bay, Laizhou Bay, Central Shallow Sea Basin and Bohai Strait, so the Bohai Strait belongs to the Bohai Sea area.[4]
The boundary of Liaoning Shandong inter provincial sea area is located in the Laotieshan Waterway in the north of the Bohai Strait. The straight-line distance from Beihuang City Island in Changdao County, Shandong Province to Laotieshan in Lushun is about 40 kilometers. The main marine function is the sea navigation channel.Liaoning and Shandong provinces have never had conflicts or disputes in the history of the sea area, and the natural and social background of sea area demarcation is not complex.After the draft of delimitation of Liaoning Shandong sea area was initially formed in July 2003, the delimitation office of the State Oceanic Administration has coordinated and demonstrated the draft of delimitation of Liaoning Shandong sea area for more than a year.Since Liaoning and Shandong provinces basically adhere to their respective opinions, the Boundary Survey Office of the State Oceanic Administration organized the Second Institute of Oceanography to conduct another multi beam submarine geomorphology scanning and verification survey in the sea area.[5-6]
Sea level at Laotieshan in the northern section of Bohai Strait
Sea level at Miaodao Islands in the south of Bohai Strait
Geology and geomorphology
Announce
edit
Geological alteration
The Bohai Strait (together with Miaodao Islands), located in the east of the Bohai Sea subsidence zone, is a branch of the Changbaishan system and part of the Jiaoliao uplift.
In the late Proterozoic era, the Miaodao Islands were not separated from each other and connected with the northern and southern continents, commonly known as the "Jiaoliao Shield".During the Yanshan tectonic movement 140 million years ago and the later Himalayan orogeny, a series of NEE, NNW, NNE and NE trending faults occurred successively.Since then, the ancient continental block fault depression has separated into the prototype of islands, thus forming the Bohai Strait.[7]
Since the late Pleistocene, there have been three major transgressions and regressions, and the islands have undergone successive "carving".After the "Lushan Glacial Age" about 100000 years ago, the climate entered the warm stage of interglacial period. Glaciers melted, ocean water increased, and sea water rose, which exceeded the Shanya Valley between Jiaoliao and Liaohe, poured into the ancient Bohai Lake and the North China Plain, and even flooded Cangzhou (historically known as "Cangzhou transgression").Since then, the fractured Jiaoliao Shield has become an island in the sea.The surging sea water has occupied the Bohai Sea for tens of thousands of years. About 70000 years ago, the "Dali Ice Age" began. The land suddenly became cold, and the ice and snow were confined. Most of the land precipitation from the evaporation of sea water could not flow back to the sea. The sea water gradually withdrew from the Bohai Basin. In the past, the sea floor became land, and the Miaodao Islands and the Thousand mile Plain became one of the hills on the land.[7]
The cold climate began to warm up 45000 years ago, and transgression occurred again.The scale of this transgression was larger than that of the previous one, and it extended to Xianxian County in Hebei Province (known as "Xianxian transgression" in history), leaving traces of this transgression along the Bohai Sea coast.For example, the Shedao Island in Liaoning Province has a sea erosion cave left by this transgression at an altitude of 100 meters.Beigou Commune in Penglai County is located on the north slope of the west of Yingkou, Beilinyuan, about 4km away from the coast. It still retains intact marine erosion terrains of quartzite, and has 5-6m high marine erosion columns.At the altitude of 60~70 meters in the Miaodao Islands, there are generally signs of sea erosion.After the transgression in Xianxian County, the sea still retreated.[7]
In the Holocene, the climate entered a warm period after the ice age.Glaciers melt in large numbers and the sea level rises again.During the ice age, the sea floor of the Bohai Sea, once a marsh grassland, became a vast sea again.The coast of the Bohai Sea has been pushed to Huanghua, Jinghai and Tianjin (known as the "Yellow Sea transgression" in history).The sea erosion line reaches the Jiuzhang Cliff of Beichangshan Island and the "Banpo" of Beizhuang, Daheishan Island (both about 15m above the sea level today).After this transgression, large-scale regression began again.It was not until 1300 years ago (early Tang Dynasty) that the shoreline of the island was slightly higher than that of the modern island.The whole Miaodao Islands is still in a slight change of "rising from the south to the north".[7]
geological structure
The Bohai Sea is a Cenozoic subsidence basin. The Cenozoic uplift and depression are obviously controlled by the basement paleostructure and paleogeomorphology. The entire seabed is covered by modern sediments. Only the Bohai Strait has exposed Precambrian metamorphic rocks and Mesozoic granites.The Quaternary deposits in the Bohai Sea are 300~500 meters thick.Since the Cenozoic era, the Bohai Sea area has been sinking continuously, so it has deposited several kilometers of sedimentary layers, of which the thickness of the Tertiary sedimentary layer is the largest, which is rich in oil and gas, and is one of the important oil and gas producing areas in China.[3]
The topography of the bottom of the Bohai Sea is greatly affected by rivers, and several huge fan deltas are formed underwater.Tidal delta deposits are also formed in the Bohai Strait.The Bohai Strait is deep and 57 nautical miles wide.At the end of the Pliocene in the Tertiary, the sea water flooded the Miaodao Islands, and at the beginning of the Quaternary, the sea water retreated, making the higher part of the island exposed to the water.Dozens of islands in the middle of the strait form the Miaodao Islands (i.e. Changshan Islands, whose administrative division belongs to Changdao County).[3]
Submarine geomorphology
Landform around the Bohai Strait
The underwater landform of the Bohai Strait is spectacular.The broken wall of Laotieshan Cape and Penglai Cape goes straight down to the seafloor, and Miaodao Archipelago runs across it. Tidal sand ridges hold islands, reef longitudinal extension scour troughs and erosion depressions appear between the seafloor sand ridges.Between islands or between headlands and islands, the cross sections of troughs and depressions are mostly V-shaped, and their bottoms are mostly covered with gravel, with bedrock outcrops. The terrain of the entire strait is descending in steps from south to north.The wide and deep scouring trough of Laotieshan River is located below the northernmost Laotieshan headland.[3]
terrain
The Bohai Sea can be divided into five parts: Liaodong Bay, Bohai Bay, Laizhou Bay, Central Shallow Sea Basin and Bohai Strait. Due to the inflow of rivers with large sediment concentration such as the Yellow River, Haihe River, Liaohe River and Luanhe River, the Bohai Sea has shallow water and flat terrain. The entire seabed is inclined from the three bays of Liaodong Bay, Bohai Bay and Laizhou Bay to the central shallow sea basin and the eastern Bohai Strait.
The sea floor of the Bohai Sea is flat, with an average depth of 26 meters in the middle. The sea area with a depth of less than 30 meters accounts for more than 95% of the total area of the Bohai Sea. The water depth near the estuary of the Dahe River, Laizhou Bay and Bohai Bay does not exceed 20 meters.The water area in the middle and east of the Bohai Bay is deep, and it is an underwater accumulation basin in the Bohai Sea.On the east and west sides of the underwater accumulation basin, the slope is relatively large.The deepest is 86 meters, located in the middle of the Bohai Strait.[3]
waterway
The islands in the strait are divided into 6 main watercourses (12 in size). The watercourses in the north are wide and deep, while those in the south are narrow and shallow.Among them, the Laotie Mountain Waterway, from the west corner of Laotie Mountain to Beihuang City Island, is 22 nautical miles wide and 50~60 meters deep. It is the main channel from the Yellow Sea to the Bohai Sea.The current flowing into the sea increases its velocity due to the narrow terrain (up to 260 cm/s), and is divided into two branches after flowing in from the waterway: one branch flows northwestward, scouring a U-shaped trough with a length of 80 km and a width of 30 km along the seafloor, and the depth locally reaches 70 meters. At the north end of the trough is distributed a finger shaped underwater sand bar, commonly known as "Liaodong Shoal", which is a sandy shoal;The other branch goes westward and crosses the central basin to form a tongue shaped deep trough extending to the north of Bohai Bay.In the Laotieshan Waterway, there are gravels with a grain size of 2~7cm. The gravels are composed of quartzite, granite or phyllite, which are the products of coastal and submarine scouring. In some places of the waterway, bedrock is exposed at the bottom.Several channels in the south of the Strait are the main channels for the Bohai Sea water to flow back to the Yellow Sea.[3]
Sea bottom
Gravel (G): mainly seen sporadically in the Bohai Strait.In Dengzhou Waterway, the diameter of gravel can reach more than 10 cm, in angular or sub angular shape. The lithology is quartzite and siliceous limestone, and the surface is often attached by benthos.Bedrock is exposed in some places of the waterway.In the south of Laotieshan Road, calcareous gravel is found, which is transformed from calcareous nodules in loess.[8]
Fine sand (FS): northern Bohai Strait (120 ° 30 ′ - 122 ° 00 ′ E, 38 ° 10 ′ - 40 ′ N): fine sand is yellowish gray or gray, mixed with a small amount of medium coarse sand and clay, containing a small amount of gravel and calcareous, ferromanganese nodules.There are many shells within a few centimeters of the sediment surface.[8]
Silty fine sand (TS) and fine sandy fine sand (ST): These two kinds of sediments in the Bohai Strait are also distributed in the periphery of fine sand deposits, from the sea area north of Yantai to the northwest, passing through the Bohai Strait and extending to the middle of the Bohai Sea.[8]
Clay silt (YT): starts from the south of Bohai Bay in the northwest, passes through the north of Laizhou Bay in the east, crosses the Bohai Strait, and goes straight to the North Yellow Sea,[8]
Sand silt clay (STY): mainly in the west of Bohai Strait[8]
coast
Bedrock coast at Laotieshan Cape, north end of Bohai Strait
Bedrock coast at Penglai Pavilion at the southern end of Bohai Strait
The coasts at both ends of the Bohai Strait, the north coast of Laotieshan Gaiping, Dalian, Liaoning, and the south coast of Hutouya, Laizhou, Shandong and Dengzhou Cape, Penglai County, Shandong are all outside the bedrock sandy gravel coast.[4]The slope along Penglai coast at the south end is relatively large, with many reefs and narrow beach surface.[9]
Island distribution
Miaodao Islands
Located in the south central part of the Bohai StraitMiaodao IslandsIt is composed of 32 islands, with a total area of 52 square kilometers.Miaodao Islands, 32 islands (21 in Shandong Provincial Records of the People's Republic of China) are distributed in a south-west~north northeast direction.South Changshan Island, North Changshan Island, Daheishan Island, Xiaoheishan Island, Miao Island (commonly referred to as the South Five Islands) in the south, and Tuoji Island, Daqin Island, Xiaoqin Island, Nanhuang Island, and Beihuang Island (commonly referred to as the North Five Islands) in the north are inhabited islands, and the rest are uninhabited islands.
The largest island is Nanchangshan Island, with an area of 12.3 square kilometers, and the smallest island is Xiaogaoshan Island, with an area of 0.0008 square kilometers.The highest island is Gaoshan Island, 202.8 meters above sea level;The lowest island is Dongzui Shidao, 7.2 meters above sea level.The north-south island is 56.4km long at most, and the east-west island is 30.8km wide at most.
List of Miaodao Islands
Island name
relative position
North latitude, east longitude (degrees)
Longest
(km)
Widest
(km)
the measure of area
(square kilometers)
Shore length
(km)
Maximum altitude (m)
South Changshan Island
South end of the archipelago
37°55′，120°44′
seven point two two
four
twelve point eight zero
twenty point zero two
156.1 Huangshan
North Changshan Island
North of South Changshan Island
37°58′，120°42′
five point one
two point six
seven point eight seven
thirteen point eight
1957 Mount Song
Daheishan Island
Western end of the southern part of the archipelago
37°58′，120°36′
four point two two
two point seven
seven point four seven
twelve point zero three
189 Old Montenegro
Xiaoheishan Island
East of Daheishan Island
37°58′，120°39′
one point nine
zero point eight five
one point two nine
five point three
95.1 Dashan City
Miaodao
Centered in the south of the islands
37°56′，120°40′
two point six five
one point one
one point four three
six point seven
98.3 Phoenix Mountain
Tuoji Island
Central Islands
38′10°，120°45′
four point seven five
three point nine
seven point zero five
seventeen point six eight
198.9 Shuangding Mountain
Dachin Island
North of Tuoji Island
38°.18′，120°49′
four point nine
two
six point four four
fourteen point five five
202.44 Nanshan
Xiaoqin Island
North of Daqin Island
38°20′，120°50′
two
zero point eight five
one point one one
six point four four
148.9 Eagle Paving
Nanhuang City Island
South of Beihuang City Island
38°21′，120°54′
three point one
one point six
one point eight three
twelve point zero nine
100.9 Dading Mountain
Beihuang City Island
Northern end of the archipelago
38°23′，120°54′
two point eight five
one point nine
two point six two
ten point three two
159.8 North Peak
Fish scale island
Southeast of Daheishan Island
37°55′，120°37′
zero point one seven
zero point one
zero point zero one
zero point three eight
nineteen point five
Nantuizi Island
Southeast of Daheishan Island
37°56′，120°37′
zero point eight six
zero point four
zero point one three eight
two point three one
fifteen point one
Niutuizi Island
South to the west of Miaodao
37°55′，120′40′
zero point five five
zero point three five
zero point one one
one point three eight
twenty-six point four
Yangtuizi Island
North to the west of Miaodao
37°56′，120°40′
zero point five five
zero point three five
zero point one one
one point three eight
twenty-six point four
Sesame Island
North of Miaodao
37°57′，120°41′
zero point one four
zero point one
zero point zero two
zero point three eight
nineteen point six
Juju Island
North of Xiaoheishan Island
37°58′，120°39′
zero point one nine
zero point zero eight
zero point zero one
zero point four
twenty-two point four
Scorpion island
Northwest of Tanglang Island
37°59′，120°39′
zero point one
zero point zero four five
zero point zero zero four
zero point two one
nine point eight
Houji Island
Due north of Xiaoheishan Island
38°03′，120°38′
one point one
zero point four seven
zero point two eight
two point seven five
ninety-two point nine
Xiaohuji Island
Northwest of Houji Island
38°03′，120°38′
zero point zero four
zero point zero two five
zero point zero zero zero nine
zero point two two
twenty-three point three
Alpine island
Due north of Houji Island
38°08′，120°38′
one point three
zero point seven
zero point four six
three point five five
two hundred and two point eight
Xiaogaoshan Island
Southeast of Gaoshan Island
38°07′，120°38′
zero point zero three five
zero point zero two five
zero point zero zero zero eight
zero point two two
twelve point six
Dazhushan Island
East end of central archipelago
38°01′，120°56′
two point one
one point two
one point four nine
five point two zero
one hundred and ninety-four point five
Xiaozhushan Island
West of Dazhushan Island
38°01′，120°52′
zero point eight
zero point four
zero point two four
two
ninety-seven point two
Car from the island
Northwest of Xiaozhushan Island
38°04′，120°51′
zero point six four
zero point one
zero point zero five
one point two five
seventy-three point five
Tuizi Island
South side of Tuoji Island
38°09′，120°44′
zero point four two
zero point one five
zero point zero five
one point zero six
sixty point three
Dongzui Shidao
Southeast of Tuoji Island
38°09′，120°47′
zero point zero five
zero point zero four
zero point zero zero two
zero point one five
seven point two
Shanzui Shidao
Northeast of Tuoji Island
38°11′，120°45′
zero point zero six five
zero point zero two
zero point zero zero one three
zero point one seven
sixteen point seven
Biegaishan Island
North of Xiaoqin Island
38°21′，120°50′
zero point two
zero point one one
zero point zero two
zero point five seven
forty-two point eight
Slope reef island
Northeast of Nanhuang City Island
38°21′，120°54′
zero point zero eight five
zero point zero two
zero point zero zero one seven
zero point one five
twelve
Mantis Island
West of North Changshan Island
37°58′，120°40′
zero point nine seven
zero point two five
zero point one five
two point zero one
fifty-four point seven
Wave island
Northwest of Scorpion Island
37°59′，120°40′
zero point five
zero point four
zero point one three
one point eight six
thirty-five point nine
Ma Gun Stone Island
North of Wave Blocking Island
37°59′，120°39′
zero point one
zero point zero one six
zero point zero zero one five
zero point one four
eight point nine
[10]
Laotieshan Cape is located at the southernmost tip of Liaodong Peninsula, southwest of Lushunkou District, Dalian City.It is also called Laotie Mountain Cape, Laotie Mountain Head and Laotie Mountain Mouth.The connection with Penglai Cape of Shandong Peninsula is the boundary between Bohai Sea and Yellow Sea.Under the south cliff is Laotieshan Waterway.With lush vegetation, it is a habitat for birds.In autumn, migratory birds migrate southward through this area, so it is called "Bird Station" or "Hundred Birds Garden".Laotieshan Cape is the north end of the boundary between the Bohai Sea and the Yellow Sea.The famous Bird Island and Snake Island are all here.
Marine hydrology
Announce
edit
tide
According to the Chronicles of Changdao County, the tidal nature of the Bohai Strait is regular semi diurnal tide, with the rule of two rises and two retreats in one day and night, commonly known as "four tides".The direction of the current shifts from left to right, turning around once a day and night, which is called "four opening current".It takes 12 hours and 24 minutes for the tide to rise and fall. It takes 24 hours and 48 minutes for the tide to rise and fall twice a day and night. According to the lunar calendar, half a month forms a cycle.Therefore, the tide time of the first day of the lunar calendar corresponds to that of the sixteenth day of the lunar calendar, the fifth day of the lunar calendar, and the twentieth day of the lunar calendar.From the 30th day of the lunar calendar to the 4th day of the lunar calendar, and from the 14th to the 18th National Congress of the Communist Party of China, it is commonly known as the "Great Flood Sea".In the rest of the time, the tide speed is slow and the tide is small, which is commonly known as "dead flood foundation" or "dead bottom".The geographical distribution of tidal height is higher in the north than in the south. The average high tide in August is 212 cm in Tuoji Island and 143 cm in South Changshan Island.Tidal range distribution: 124 cm for Tuoji Island and 119 cm for South Changshan Island.The average high tide interval was 10:10 on Tuoji Island and 10:4 on South Changshan Island.The average low tide interval was 4:6 on Tuoji Island and 3:53 on South Changshan Island.It is 163 cm for spring tide Shengtuoji Island, 161 cm for South Changshan Island, 130 cm for neap tide Shenghuaji Island, 131 cm for South Changshan Island, 89 cm for the average sea level, and 90 cm for South Changshan Island.[11]
trend
The main waterway of the tidal current in the Bohai Strait is mostly east-west flow, and the harbor is mostly backwater flow.The north waterway flows to the west, and the south waterway flows to the east.This rule of "going north and going south" is particularly obvious in winter.In summer, the southern sea area is generally between 0.6 and 1.03 m/s, and Daheishan Island is the smallest, 0.6 m/s;The northern sea area is generally about 1.25 m/s, and the maximum value of Tuoji Waterway is 3.7 m/s.The current velocity of the bay backwater is smaller, and the Houkou Bay of Tuoji Island is only about 0.4 m/s.
sea wave
The wave pattern in the Bohai Strait is mainly "wind wave".In autumn and winter, the wind and waves are northward, and in summer, the wind and waves are southward.The seasonal variation of wave height is: the monthly average wave height in winter (October to January of the next year) is 1.1 m, the monthly average wave height in spring (February to April) is 0.47 m, the monthly average wave height in summer (May to July) is 0.5 m, and the monthly average wave height in autumn (August to September) is 0.8 m.Over the years (1960~1981), the average annual wave height is 8.6 meters, and the extreme maximum wave height is 10 meters, which occurs in the Beihuang Island sea area;The average change of wave height period (peak A - peak B time unit) is 3.4 seconds, and the maximum period is 13.9 seconds.[11]
Sea surface temperature
The annual average sea surface temperature in the Bohai Strait over the years (according to the survey data from 1962 to 1979, the same below) is 11.5 ℃.The monthly average temperature is the highest in August, 22.1 ℃;The lowest temperature is 2.5 ℃ in February.The extreme maximum temperature was 27.3 ℃ (appearing on August 28, 1963), and the extreme minimum temperature was - 1.2 ℃ (appearing on February 28 and March 1, 1969).The temperature rises fastest from April to July every year, with an average temperature rise rate of 4.7 ℃/month;The temperature drops fastest from October to January of the next year, with an average cooling rate of 4.1 ℃/month.The water temperature changes between years, the northern sea area is relatively slow, with an annual range of 22.8 ℃;The southern sea area is relatively fast, with an annual range of 26 ℃.[11]
Sea surface salinity
The salinity of the sea surface in the Bohai Strait is 31.33 ‰ on average over the years.The extreme maximum value was 33.26 ‰ (appeared on April 3, 1962), and the extreme minimum value was 24.79 ‰ (appeared on July 6, 1964).Within the year, February is the highest, with an average of 31.82 ‰ over the years;It was the lowest in August, with an average of 30.49 ‰ over the years.The apparent salinity of the sea water in the northern and southern sea areas (bounded by Tuoji Island, the same below) is higher in the northern sea area and lower in the southern sea area.[11]
Seawater transparency
The transparency of the sea water in the Bohai Strait is quite different from that in the north and south sea areas.The northern sea area is generally between 3.7 and 9.5 meters, and the highest value in the Nanhuang City Island sea area is 13.8 meters;The southern sea area is generally between 1.7 and 3 meters, and the minimum transparency in Miaodaotang is only about 0.2 meters after strong wind.During the year, the seawater transparency has obvious seasonal changes.Generally, the transparency is small in winter and large in summer.After strong wind, the transparency of sea water is generally small.[11]
Sea fog
There are fewer foggy days in the Bohai Strait. The annual average foggy days are 28 days, mostly advection fog, and less radiation fog.The sea fog is the most in spring and summer, accounting for 86% of the whole year's sea fog days, mostly concentrated in June to July;There are fewer foggy days in autumn and winter, with the least foggy days from September to October.Advection fog is characterized by high humidity, wide range and long duration. It is usually generated at night and lasts until noon of the next day, some lasting more than 4-5 days.The radiation fog lasts for a short time and is usually generated at night or in the morning. It mostly weakens or dissipates with the exposure of the sun.Some can disappear within a few hours or minutes, and some can last for 1-2 days.[11]
sea ice
Due to the influence of the mainstream current of the Yellow Sea, the water temperature in the Bohai Strait is relatively high in winter, and there is no ice sealing in the estuary and harbor.The southern islands sometimes have a small amount of thin ice and ice feet along the coast in severe winter, which has no impact on production and traffic.[11]
Sea glow
Spark type (H) sea lights often appear in the Bohai Strait at night. Fishermen call it "sea fire", which can be seen all year round.According to the observation from 1962 to 1979, the frequency of no seawater luminescence (level 0) accounted for 14%, the frequency of level 1 accounted for 67%, the frequency of level 2 accounted for 17%, the frequency of level 3 accounted for 2%, and the frequency of level 4 was quite rare (twice in 18 years).The annual average number of luminous days is 201 days.[11]
plankton
The content of plankton in the Bohai Strait is very high, including phytoplankton and zooplankton.According to the survey in 1985, the annual average plankton amount was 2.887 million/m3.Among them, phytoplankton accounts for 98%.In the year, there are two high peaks in the south and north sea areas: 20.72 million/m3 in the south sea area in March and 5.193 million/m3 in November;In the northern sea area, 13.96 million pieces/m3 were in March and 1.3 million pieces/m3 were in October.[11]
natural resources
Announce
edit
Mineral resources
In the south of Bohai Strait, epidote and zircon are relatively high, reaching 28% and 2-5% respectively;[12]Iron, aluminum and manganese: the low content area is in the north of the Bohai Strait.The northern bohai strait is a low content area of manganese in bohai sediments.Calcium carbonate: there is a small local high content area near the Bohai Strait, which is mainly related to the fact that there are more shells in the sediment.[13]
fishery resources
The small yellow croaker is the main fishing resource in the history of the Bohai Strait. The traditional fishing season of the small yellow croaker (Pseudosciaena crocea) fishing ground is: from 3 to 4 days after Qingming Festival to 4 to 5 days before the beginning of summer in Penglai coastal fishing ground, and the peak flood season is from 2 to 3 days before grain rain to 5 to 6 days after grain rain.The fishing ground in the Bohai Strait starts 7 to 8 days after cold dew and ends with heavy snow. The peak flood season starts 3 to 4 days before the beginning of winter and ends with light snow.Since the 1960s, the traditional fishing grounds have been transferred to the marine island fishing grounds, Yushan fishing grounds, Dasha fishing grounds and Shidao fishing grounds.In the late 1970s, Lvsi Fishing Ground, Changjiang Estuary Fishing Ground and Zhoushan Fishing Ground were opened up.[14]
Hairtail is also a major fishing resource in the history of the Bohai Strait. The traditional fishing season is: Penglai coastal fishing ground, which starts 1 to 2 days after the beginning of summer and ends around the summer solstice, and Wangxun Lake, which starts 1 to 2 days after Xiaoman and ends 3 to 4 days after awning.The fishing ground in the Bohai Strait starts 7 to 8 days before frost and ends before heavy snow, and the peak flood season starts 2-3 days before the beginning of winter and ends before light snow.Since the mid-1960s, the fishery has gradually shifted to Qinglianshi Fishery, Dasha Fishery, Haijiao Fishery, Changjiang Estuary Fishery and Zhoushan Fishery.[15]
The Spanish mackerel fishing season is mainly in the coastal fishing grounds of Penglai. It starts from white dew and ends about 10 days before the beginning of winter. The peak flood season is from the autumnal equinox to around frost.[16]
The fishing season of the flounder fishery is mainly in the fishing grounds around the islands of Miaodao Islands. It starts around the beginning of spring and ends at the end of Qingming Festival. The peak flood season lasts from 4 to 5 days after the rain to about 10 days before the spring equinox.After the 1970s, high-power trawlers emerged, and the fishing grounds expanded to Shidao Fishing Ground and Qinglianshi Fishing Ground.The fishing season is from early spring to February and from autumn to winter to December.[17]
The bottom miscellaneous fish fishing ground is a fishing ground in the northeast of Yantai and the coastal area of Penglai.The fishing season is from spring equinox to light snow.Tanziwang's fishing ground is 13~15 Tuoshui in the east coast of Changshan Island in the south and north.The fishing period is 50~60 days from Qingming to Xiaoman.[18]
During the fishing season, the hole ray fishery is located in the sea area between Huangcheng Island and Laotieshan (Laotieshan Waterway) in the Miaodao Islands.The dry hook operation lasts from light snow to around Qingming Festival.[19]
During the fishing season, the puffer fish fishing ground is located in the east of Huangcheng Island, the northern waters of Yantai and the waters near Chrysanthemum Island in the Miao Islands.The operation time of the hook is from the summer solstice to the beginning of autumn.Since the 1980s, the fishing ground has expanded to the south and southeast waters of the ocean island, and the fishing period is from late July to early November.[20]
The fishing season of shrimp fishing ground: Chengshantou offshore fishing ground starts 6-7 days before the spring equinox and ends before and after the grain rain, and the peak flood season lasts from about 10 days before the Qingming Festival to 1-2 days after the Qingming Festival.Penglai coastal fishing ground starts 3 to 4 days before Tomb Sweeping Day and ends 3 to 4 days before the beginning of summer. The peak flood season starts 4 to 5 days after Tomb Sweeping Day and ends 1 to 2 days before grain rain.The fishing ground in the Bohai Strait starts about 10 days after cold dew and ends 5 to 6 days before light snow. The peak flood season is from 7 to 8 days after frost to around the beginning of winter.In the 1960s, with the increase of high-power trawlers, shrimp resources declined seriously.In 1965, the state formulated the policy of "breeding in summer and catching in autumn", and uniformly stipulated the time when ships enter the Bohai Sea for operation in autumn.After the prawns come out of the bay, chase them to Shidao Fishing Ground or further waters.[21]
During the fishing season, the scallop fishery is near Qindao and Huangcheng Islands of Miaodao Islands.The operation time of pulling net is from light snow to the beginning of spring.In the 1960s, fishing production was stopped due to resource depletion.[22]
The sea area near Miaodao Islands has sea cucumber resources during the fishing season of the sea cucumber fishing ground.Before 1953, they were collected all year round.Since 1953, in order to protect the resources of the sea cucumber, the county has stipulated that the arrest prohibition period of Qindao and Huangcheng Islands is from May 15 to July 5;The fishing ban on other islands lasts from May 10 to June 30.In 1964, it was stipulated that the fishing ban on all islands was from May 25 to July 15.In 1973, the system of inter island annual rotation was implemented.[23]
The abalone fishing season is from the summer solstice to cold dew.Abalone is banned during the same period as sea cucumber.Since abalone resources are rarely found on the five southern islands in history, it is said that "abalone is not the pearl gate".In the 1980s, a small amount of abalone resources were found in the northern waters of South Changshan Island.[24]
Biological resources
Taking Miaodao Islands as an example, the biological resources in the Bohai Strait are as follows:
marine organism
Fish: mainly wrinkled lip shark (shark), spotted star shark (white spot shark), Lu's hammerhead shark (Xianggong hat), white spotted horned shark (spiny shark), Chinese Tornado ray (Dayauzi), Kong ray (Labio), (Yellow border land), Pacific herring (herring), Shounan green scale fish (green scale), Chinese herring (fire scale fish, fast fish), (water rotten), wind coilia (wind tail fish)Yellow crucian carp (hairpin), long snake mullet (barracuda), eel (eel), sea eel (wolf tooth eel), star eel (long worm fish), flat jaw needle fish (beam fish), (fine needle fish), ray (swallow fish), cod (big head fish), sea dragon, hippocampus, Youshu (sweet shuttle), perch (perch), yellow stripe (yellow golden ox), loach (shady fish), small yellow croaker (small yellow flower)Yellow croaker (yellow croaker, copperfish), (croaker), called white croaker (small white fish), white croaker (white rice fish), spiny headed baby plum (big head treasure), black snapper (sea bream), red snapper (red Jiaji), (black wife), scaly fish (boat fish), six line fish (yellow croaker), sea crucian carp (crucian carp), line flounder (big head cotton turtle, catfish), hairtail (swordfish)Mackerel (chub mackerel), blue spotted mackerel (Spanish mackerel), silver pomfret (mirror fish), pike tail piranha (Nili Gouzi), short fin damselfly (red headed fish, magpie), green fin fish (warbler), (plait fish, pointed head fish), Japanese flounder (big tooth piece), spotted flounder (flower point piece mouth, oil piece), tall snapper (long neck), yellow plaice (small mouth fish), stone flounder (feeding fish)Single tongue sole (middle tongue), half smooth tongue sole (sole rice), wide body tongue sole (sole rice), short snout and three spines (machine gun leg), green fin horse face (leather craftsman), insect pattern oriental (face tympa), lead dot round (tympa), fish teeth single nose blunt (yellow tympa), (ruohou fish, scale fish), etc.[25]
Shrimp and crab: mainly Chinese shrimp (prawn), eagle claw brown shrimp (eagle claw shrimp), big mole cricket shrimp, shrimp (shrimp crawling), black spot mouth shrimp, spiny hermit crab, Japanese Guangong crab, Longxian boxing crab, four tooth rock crab, three wart swimming crab (flying crab), Japanese sturgeon, hairy mitten crab, long finger mitten crab, ball meat mitten crab (crab flow), Chinese mitten crab.Molluscs: Shih's scallop, short limpet, bamboo clam, purple mussel, single tooth snail, rust concave snail, Korean corolla small moon snail, short seashore snail, pearl belt foundation snail, pearl belt crab guard snail, red snail, verrucous litchi snail, yellow mouth litchi snail, fragrant snail, common weaved snail, longitudinal rib weaved snail, half pleated weaved snail, small sea cow, kuai clam, protruding shell muscle clam, black partial top clam, chlamys farreri scallopHaliotis discus hannai, oyster moth, Dalian Bay oyster, near river oyster, oyster, Philippine clam, purple stone clam, razor clam, etc.Algae: Chlorophyta includes small reef membrane, reef membrane, Ulva pertusa, Enteromorpha prolifera, Enteromorpha marginalis, feather algae, Chaetomium rigidum, and Erythrina.The Phaeophyta includes water cloud, filamentous algae, mucous membrane algae, Haiyun, acid algae, spotted leaf algae, cysticercus, hemerophyllum, chenodensis, kelp, undaria pinnatifida, netted algae, forked netted algae, staghorn, sargassum, sea artemisia, copper algae, sargassum fusiforme, sargassum fusiforme, sargassum fusiforme, sargassum sargassum sargassum sargassum, giant algae, etc.The Rhodophyta includes Porphyra glycyrrhizae, Hyssophora lasiocarpa, Cladocera vermicularis, Asparagus angustifolia, Shihualai, Gracilaria elegans, Capillaria cristata, Leptoptera ligulate, Coralline alga, Coralline alga, Sea membrane, Antheraea cervicornis, Cladosporium mucronatum, Monochamberella, Gracilaria gracilaria, Gracilaria gracilaria gracilaria, Gracilaria lemarum, Cladosporium biflorum, Rhododendron chamaejasme, Sclerotium, Sclerotinia, Annelida, Trident, SerissaTop group alga, choriophyte, filamentous alga, hornwort, concave top alga, pine knot alga, duck feather alga, mossy duck feather alga, etc.[25]
Other types include sea cucumber, purple sea urchin, jellyfish, sea pan, seals, dolphins, sea turtles, hawksbill, whales, and mullet.[25]
Terrestrial organism
It mainly refers to the creatures on the Miao Qun Islands.
Animals: birds are mainly migratory birds, with 232 species belonging to 45 families and 18 orders.The red crowned cranes, white tailed sea eagles, white shouldered eagles, giant swans, great bustards, magpies, grass bustards, etc. are under state protection.There are also peregrine falcon, heron, mallard duck, bean goose, goshawk, sparrow hawk, quail, yellow legged three toed quail, red breasted frog, Dong chicken, oyster snipe, big curlew, woodsnipe, green legged snipe, black tailed gull, silver gull, flat billed auk, rock pigeon, mountain turtle dove, large cuckoo, four tone cuckoo, common nighthawk, white throated swallow, common green finch, Sambo bird, Dai Sheng, small spotted woodpecker, small sand bailingSmall skylark, golden rumped swallow, grey mountain pepper bird, white headed bulbul, peaceful bird, tiger pattern shrike, black pillow oriole, hair crown curling tail, grey bird, big beaked crow, grey magpie, magpie, blue songbird, tiger spot mountain thrush, grey backed warbler, white bellied thrush, yellow browed warbler, light footed warbler, daiju, longevity bird, great tit, dark green embroidered eye, goldfinch, yellow finch, yellow eyebrow and seagull, sea cormorant, etc.Insects and beasts mainly include agkistrodon halys, white striped snake, tiger spotted snake, skink, tuyuan, scorpion, etc.[25]
In the north of the Bohai Strait, Dalian is located in the warm temperate zone, with a sub humid monsoon climate in the warm temperate zone. There is no cold winter, no cold summer, and four distinct seasons.The annual average temperature of the whole region is about 10 ℃, of which August is the hottest, with an average temperature of 24 ℃. The longest consecutive days with the daily maximum temperature greater than 30 ℃ are 10-12 days, and the annual extreme maximum temperature is about 35 ℃.January is the coldest month with an average temperature of - 4.5 to - 6 ℃ in the south and an extreme minimum temperature of about - 20 ℃.The frost free period is 180~200 days.
The annual average precipitation is between 550 and 950 mm, increasing from southwest to northeast.60~70% of the annual precipitation is concentrated in summer, mostly in the form of rainstorm;12~15% in spring;Autumn accounts for 15-20%, and winter only accounts for about 5%.Due to ocean regulation, night rain is more than day rain, especially in summer.
The prevailing wind direction varies significantly with the seasons.The northerly monsoon prevails in winter, and the southerly monsoon prevails in summer. Spring and autumn are the conversion seasons of southerly and northerly winds.The number of days with strong wind of level 6 or above is 90-140 days per year in coastal areas and 35-50 days in inland areas, with the most in winter and spring and the least in summer.[26]
The southern part of the Straits has a continental climate in the east Asian monsoon region, with a continental degree of 52.3%.Influenced by the alternation of cold and warm air, combined with the temperature regulation effect of seawater, the four seasons are characterized by strong wind in spring and late warming, frequent rain in summer and cool climate, slow drying and cooling in autumn, and frequent cold waves in winter.[27]
The average total sunshine hours over the years (1959~1985, the same below) is 2542 hours, and the annual sunshine rate is 58%.May has the most sunshine hours, 269.7 hours;The sunshine hours in December are the least, 151.1 hours.[28]
The annual average temperature over the years is 11.9 ℃.The highest year is 12.8 ℃ (1959, 1961, 1983), and the lowest year is 10.7 ℃ (1969).The extreme maximum temperature is 36.5 ℃ (July 30~31, 1959), and the extreme minimum temperature is 13.3 ℃ (January 4, 1970).The average temperature in January is the lowest,~1.6 ℃;The average temperature in August is the highest, 24.5 ℃.The annual range is 26.1 ℃.The temperature changes are characterized by the fastest rise in May and the largest drop in November.[29]
The Bohai Strait is located in the wind tunnel, with an average annual gale day of 67.8 days.Niangou on Beihuang Island lasts for 100.8 days, with the maximum age of 129 days.The number of strong wind days throughout the year is the most in winter, with an average of 23.4 days, 19 days in spring and autumn, and the least in summer, with an average of 6.6 days.The maximum wind speed occurred in the No. 9 typhoon on August 19, 1985, which was 40m/s.There are mainly five weather systems that generate strong wind: cold wave and strong wind in autumn and winter, which are formed by Siberian cold air breaking southward, with wind force up to 7~10, mostly northerly, lasting 2-3 days each time.In spring, the strong wind of Mongolia cyclone is formed from Mongolia to northeast China. The wind force can reach 6~10, mostly southwest wind, lasting for 1-3 days each time.At the turn of spring and summer, the strong wind of the Jianghuai cyclone is formed by the strong development of the cyclone, which is generally 6-7 southeast wind to 8-10 northeast wind, lasting no more than 24 hours.Typhoon In late summer and early autumn, due to the influence of the Pacific typhoon periphery, there are always 6~10 strong winds (the wind direction is changeable).Thunderstorm gust In summer thunderstorm weather, sometimes accompanied by 8-10 northerly gust.[30]
The average number of precipitation days over the years in this region is 80 days.The average annual precipitation is 555.5mm.Among them, spring accounts for 14%, summer accounts for 59%, autumn accounts for 22%, and winter accounts for 5%.In 1973, the annual precipitation was the largest, 881.4 mm;At least 282.3 mm in 1965.The precipitation within the county is decreasing from south to north, with an annual difference of more than 100mm.Since the 1970s, spring drought has frequently occurred, and sometimes summer drought has also occurred. The annual rainfall tends to decrease.[31]
The annual average frost days in this area over the years are 121.1 days.The average first frost day is December 1 (October 31 at the earliest), and the last frost day is March 31 (April 16 at the latest).The date between the first frost and the last frost is 154 days at most and 98 days at least.The annual average frost free period is 245.6 days, 276 days at most and 204 days at least.The annual average icing days over the years are 127.8 days, starting on November 21 (the earliest November 5) and ending on March 21 (the latest April 7).The date between the first ice and the last ice is 148 days at most and 113 days at least.[32]
Channel shipping
Announce
edit
Channel conditions
The Bohai Strait is 105.56 kilometers wide, and Miaodao Islands occupy three fifths of the sea surface of the Strait, dividing the Strait into 14 waterways (straits).The islands of Changdao County occupy three fifths of the sea surface of the Bohai Strait, of which the Miaodao Islands are composed of 18 islands and many reefs, dividing the Strait into 12 waterways and 2 navigation gates.Only three waterways (Laotieshan Waterway, Changshan Waterway, Miaodao Strait (also known as Dengzhou Waterway, which is limited to ships with a gross tonnage of less than 200 tons) are allowed to be navigable by commercial ships, and other waterways are prohibited from navigation.Anchoring and fishing are prohibited in the waterways of Miaodao Islands.[33]
Channel and route of Bohai Strait
Laotieshan Waterway, located between Beihuang City Island and Laotieshan Cape, is 42.2km wide in east-west direction and occupies two fifths of the sea surface of the strait. The main channel is 42~78m deep with sediment bottom.yesYellow SeaThe main channel for seawater to enter the Bohai Sea is 4-6 knots, which is strongly scoured by the tidal current. A tidal trench with a depth of 60-80 meters appears in the south. It is the widest and deepest channel in the strait, with sand and gravel bottoms and no obstacles. Navigation aids are set at Laotieshan Cape and Beilong Island, with good navigation conditions.[34]
Laotieshan Waterway
Huangcheng Waterway, located between Nanhuang City Island and Beihuang City Island, runs from east to west, 5.6 kilometers long and 1.5 kilometers wide. The main channel is 19~40 meters deep, with sediment bottom.[34]
Xiaoqin Waterway, located between Xiaoqin Island and Nanhuang City Island, runs from northwest to southeast, 4.5 kilometers long and 4 kilometers wide. The main channel is 40~50 meters deep, with sediment and gravel bottom.[34]
Daqin Waterway, located between Daqin Island and Xiaoqin Island, runs from east to west, 8.5 kilometers long and 2 kilometers wide, with main navigation depth of 31~45 meters and sediment and gravel bottom.[34]
North Tuoji Waterway, located between Tuoji Island and Daqin Island, runs east-west, with a length of 11.5 km and a width of 10 km. The water depth of the main channel is 31~50 meters. There is a reef group (North Reef) in the middle of the channel, with sediment and gravel bottom.[34]
Alpine waterway, located between Alpine Island and Tuoji Island, runs from northwest to southeast, 4.5 kilometers long and 8.5 kilometers wide, and the main channel is 20~25 meters deep, with soft mud bottom.[34]
Nantuoji Waterway is located between Cheyou Island and Tuoji Island. It runs from east to west, connects Houji Waterway in the west, and neighbors Changshan Waterway in the south. The main channel has a water depth of 10~25m and sediment bottom.[34]
Houji Waterway, located between Houji Island and Gaoshan Island, runs from east to west, 6.35km long and 7.5km wide. The main channel is 21-24m deep, with sediment bottom.[34]
Changshan Waterway, located between North Changshan Island and Houji Island, runs from east to west, 17 kilometers long and 7.5 kilometers wide. The main channel is 20~30 meters deep, with soft mud bottom.[34]
Ximen Channel is located between Daheishan Island and Xiaoheishan Island. It runs from north to south, 3 km long and 1.5 km wide. The main channel has a water depth of 7~11 meters, and is sediment laden.[34]
Baotamen Waterway is located on the east side of Xiaoheishan Island, between Lijuba Island and Wave Barrier Island, in the northwest southeast direction, 2.5 km long and 1 km wide. The main channel has a water depth of 10~15 meters, and sediment bottom.[34]
Zhenzhumen Waterway is located between the Wave Barrier Island and North Changshan Island. It runs from north to south, 0.75 km long and 1 km wide. The waterway is deep in the north and shallow in the south. The main channel is 6~14 meters deep.[34]
Tanglang Waterway is located between the Grasshopper Island and the Wave Barrier Island. It runs in the northeast southwest direction, with a length of 1 km and a width of 0.75 km. The main channel is 20~28 meters deep, with sediment bottom.[34]
Dengzhou Waterway
Miaodao Strait (Dengzhou Waterway), located between Nanchangshan Island and Penglai Cape, is 31.5km long and 6km wide in east-west direction. The main channel is 12-37m deep, with sandy bottom.[34]
Port
Long Island Port
Long Island Port, located in Quezui Bay, South Changshan Island, Long Island County, was built in 1976 and is a comprehensive port integrating passenger and freight transport.[33]
Long Island Fishing Port
The Long Island Fishing Port is located at the seaside on the west side of Digou Village, South Changshan Town.The project was started in September 1974 and completed in December 1978.The investment is 3.96 million yuan.The structure of the wharf is block gravity type, with a total length of 613m.The main wharf is 428m long, 30m wide and 4.5m deep;The auxiliary wharf is 185 meters long and 1.7 meters deep.The approach dike is 170 meters long and 10 meters wide.The harbor basin covers an area of 71440 square meters and can accommodate ships below 1000 tons.Water and oil pipelines are laid in the port, and ice bridges are erected.There are 1280 square meters of warehouses and 6500 square meters of freight yards.It is equipped with one 35m deep large well, one 104m deep pump well, and one 1400m3 and 300m3 reservoir respectively.One diving boat and one crane boat are provided.The annual average handling capacity is 8000 tons of fish cargo, 3100 tons of aquaculture products, 2400 tons of diesel oil, more than 5000 tons of materials, 9000 tons of ice and 7000 tons of water.In 1976, the Fishing Port Management Group was established, renamed as the Wharf Management Office in 1979, merged into the Fishing Vessel and Fishing Port Supervision and Management Office in 1981, and restored the Fishing Port Management Office in 1983.It is mainly responsible for calculating and collecting port charges, ship mobilization, arranging loading and unloading, and supplying water for ships.[35]
Yantai Port
Yantai Port, in the fourth year of Tongzhi's reign in the Qing Dynasty (1865), Donghai Customs built the first gravity wharf of Yantai Port - Customs Wharf (now the south wharf of Yantai Port Authority) on the west side of Yantai Port, with a total length of 257 meters, which is an east-west breakwater.By 1894, Yantai Port had successively built the Fukaisen Wharf, Zida Wharf, Shefulifu Wharf and Hutchison Wharf.In December 1996, Yantai Dalian Automobile Ferry Terminal was completed.By the end of 2005, Yantai Port had a total length of 7300 meters and 46 berths (23 berths above 10000 tons).[33]
Longkou Port, in 1918-1919, Longkou Town built a 250 meter long concrete trestle wharf on the north beach, which is the first man-made wharf in the history of Longkou Port.In December 1957, a 60m long and 20.6m wide concrete block gravity quay wall was built on the north side of the original Longkou Wharf.In 1959, a 200m long wharf was built.In October 1972, two 3000 ton medium-sized berths were built.From 1975 to May 1976, special wharves for oil and coal were built.From 1985 to 2005, a 16000 ton coal wharf, a 16000 ton general cargo wharf, a 5000 ton fuel oil wharf, a multi-purpose wharf, a bulk cargo wharf, a 5000 ton Ro Ro passenger ship wharf, a 35000 ton general wharf, a 50000 ton grain wharf, and a 50000 ton liquid chemical wharf were built.By the end of 2005, Longkou Port had a total length of 5000 meters and 21 berths (12 berths above 10000 tons).[33]
Penglai Port, located at the northern end of Jiaodong Peninsula, consists of Penglai West Port, Penglai East Port and Penglai Luanjiakou Port.Penglai West Port is located in the northwest of Penglai City, west of Tianheng Mountain. It was started in May 1958 and completed as a fishery wharf in August 1964.In 1985, the shoreline of the port wharf was 151.5 meters long.By the end of 2005, the port wharf has a coastline of 410 meters long, with four 1000 ton ro ro berths, three 500 ton passenger ro ro berths, and two cargo loading and unloading docks.Penglai East Port (also known as Penglai New Port) is located at the east side of Zaohekou River, 8 kilometers east of Penglai City. It was founded in April 1991. The wharf shoreline is 455 meters long, with 1 berth of 2000 tons, 5000 tons and 10000 tons.Luanjiakou Port is located about 10 kilometers west of Penglai City, facing Changshan Islands across the sea.It was built in April 1995.In May 2005, the 20000 ton oil wharf was completed and put into use, with a coastline of nearly 8000 meters.Penglai sea area includes Dengzhou Waterway, Pengchang Route, Penglv Route and Pengda Route, as well as the entrance and exit channels of Penglai East Port and Luanjiakou Port.Among them, Dengzhou Waterway is an important channel for ships from surrounding ports to get in and out of the western ports of Bohai Bay, Pengchang route is the main channel for land and island transportation, and Penglv and Pengda routes are the nearest routes for transportation between Liaodong Peninsula and Shandong Peninsula.[33]
Yantai Dalian Railway Ferry Port is divided into two ports: the south port is located in the north of the four jetties of Yantai Port, and the north port is located in Yangtouwa Bay, Lushunkou District, Dalian.Nangang Wharf is of pier type layout and pile foundation structure, with continuous piers and abutments within 38 meters of the root. The berth of the ferry wharf is 181 meters long, and the berth of the workboat wharf is 50 meters long.The North Port Wharf is of continuous layout and gravity structure. Two anti-collision piers are arranged at the root. The berth of the ferry wharf is 200m long, and the berth of the maintenance wharf is 220m long.Designed traffic volume: in the initial stage of 2008, the railway freight volume will be 3.5 million tons upward, 3 million tons downward, and 80000 vehicles will be rolled on/off.In recent 2010, the railway freight transport increased by 4.5 million tons, decreased by 3.8 million tons, and the vehicle roll on/roll off volume was 110000 vehicles.In the long term, in 2015, railway freight will rise by 6.7 million tons, fall by 5.7 million tons, and roll on/roll off volume of vehicles will be 180000.[36]
Dalian Port
Dalian Port, located at the southern end of Liaodong Peninsula, is close to the Yellow Sea and 90 nautical miles south to Yantai Port.The port is close to Lushun in the west, neighbors Changshan Islands in the east, and faces Weihai and Yantai across the sea in the south.It is a deep-water natural port, an important hub of land and water transportation between the north and the south, and the largest bulk grain and oil import and export port and major foreign trade port in China.Each port area of Dalian Port is mainly distributed in Dalian Bay, Dayao Bay, Changxing Island and Taiping Bay.In addition, Lushun New Port, Zhuanghe Port and other port areas are distributed outside.Dalian Bay and Dayao Bay are the main port areas of Dalian Port, Changxing Island is a new port area, and Taiping Bay is a planned port area.[37]
Railway ferry
The Yantai Dalian railway ferry starts from Yangtouwa Port, Lushunkou District, Dalian, at the southern end of the Liaodong Peninsula in the north and connects with the Northeast railway network, and ends at the Yantai Four Jetty Port in the northern part of the Shandong Peninsula in the south and connects with the Lanyan and Jiaoxin railways. It runs through the Bohai Strait, with a sea transportation distance of 86.28 nautical miles (159.8 kilometers). It is an important part of the land sea railway corridor from the northeast to the Yangtze River Delta,It is one of the "eight vertical and eight horizontal" railway transportation trunk lines in the national railway network planning.Yantai University Ferry is a comprehensive systematic project involving multiple disciplines, industries and disciplines, integrating railway, port, maritime safety supervision and ferry projects.In 1994, the Ministry of Communications, the Ministry of Railways, the Liaoning Provincial Government and the Shandong Provincial Government jointly submitted the proposal for the Yantai Dalian Railway Ferry Project to the National Planning Commission.In December 1997, the State Planning Commission approved the project.In January 2002, China Railway Bohai Railway Ferry Co., Ltd. (hereinafter referred to as Bohai Ferry Company) was registered in the State Administration for Industry and Commerce.Bohai Ferry Co., Ltd. is jointly invested and established by China Railway Construction Investment Corporation, Yantai Electric Power Development Co., Ltd. and Dalian Construction Investment Corporation as the representative of the investors and China Railway Erju Co., Ltd. under the authorization of the Ministry of Railways, Shandong Province and Dalian Municipal People's Government.As the project legal person, Bohai Ferry Company is responsible for the whole process of early planning, fund raising, construction implementation, production and operation, debt repayment and asset maintenance and appreciation of Yantai Dalian Railway Ferry.The project was commenced in October 2004, and was fully completed in September 2006 and passed the preliminary acceptance of the Ministry of Railways.[36]
At 9:55 on August 7, 2006, the first ten thousand ton "China Railway Bohai No.1" ferry set sail from Dalian and arrived at the four jetty port of Yantai at 16:28.On the morning of August 9, Yantai Terminal of Yantai University Ferry carried out the commissioning of train boarding and disembarking for the first time and achieved success."China Railway Bohai No.1" is a roll on/roll off ship for trains, cars and passengers, with a wind resistance capacity of 8 levels, a speed of 18 knots, a total length of 182.6 meters and a width of 24.8 meters.The ferry has two decks, the upper deck is a car deck, the lower deck is a train deck, and there are five rails in the railway freight car cabin. The way of getting on and off the train is tail in and tail out. The way of side in and side out is used for cars on the starboard side of the tail. Passengers get on and off the ship through the fully enclosed trestle in the middle of the ship.Safe isolation of trains, cars and passengers.The second ferry, Bohai Golden Pearl, is 161.2 meters long and 24.8 meters wide, carrying more than 1200 passengers and more than 200 vehicles.The trial voyage was successful on August 16.[36]
Car ferry
In December 1995, the project of Yantai Port Auto Ferry Wharf was completed. The wharf is an auto ferry wharf connecting Yantai and Dalian, the main highway on both sides of the Bohai Strait.This automobile ferry terminal was officially started on May 1, 1995 according to the national plan of basically building the "two longitudinal and two horizontal" trunk line of the national highway before 2000. After one and a half years of construction, two 5000 ton auto ro ro berths (including 10000 ton hydraulic structure), 25000 square meters of parking lot and access roads, buoys, harbor basins, waterways, etc. were built.The wharf part of the project is a high pile pier trestle structure, with ships berthing on both sides. The total length of the wharf is 165 meters, and the engineering design arrival and departure vehicles are 380000.[38]
Ferry links
In April 1990, Penglai Lushun passenger and cargo ro ro transport route was opened.In December 1992, the local roll on route from Yantai to Dalian was opened.In 1993, Shandong Yantai Shipping Corporation built a luxury high-speed passenger ship, which was put into operation on the Yantai Dalian route.[39-40]
Military coastal defense
Announce
edit
garrison
The southern section of the Bohai Strait is Long Island, with a special geographical location, which has always been the focus of military strategists.In the Tang Dynasty, Wuhu garrison was set up on the island, which was later placed as an important town.In the Tang Dynasty, Zhang Liang, the chief commander of the Pyongyang Daoxing Army, led 40000 troops and 500 warships to Korea via Tuoji Island.In the Song Dynasty, Shamen Island was set up.In the Yuan Dynasty, there was a Shamen patrol department.In the Ming and Qing dynasties, there were garrisons on the island.In the Qing Dynasty, from the eighth year of Xianfeng (1858 AD) to the tenth year of Xianfeng (1860 AD), the British and French allied forces passed through the Bohai Strait three times to occupy Beijing and Tianjin.In the 24th year of Guangxu (1898 AD), the Tsar Russia sent the warship "Mitri Donsky" to occupy Long Island.After the signing of the Sino Russian Grand Concession Treaty and its renewal, the tsarist Russia also tried to force the Qing government to include Long Island in the Grand Concession.In the 26th year of Guangxu (1900 AD), the Eight Power Allied Forces invaded the Bohai Strait and occupied Beijing and Tianjin.During the Russo Japanese War in 1904 and the German Japanese War in 1914, the Japanese army used Long Island as a relay station to capture Lushunkou and Qingdao.In 1912, the warships of the Northern Warlords often parked in the waters of Long Island.In 1917, the Northern Warlords planned to open Long Island as a military port, and planned to build forts on each island. Later, due to war, they failed to achieve this.In 1928, the Bong Navy came to the island to open a military port and sent the Second Fleet of Coastal Defense to Long Island.In 1939, the Japanese puppet army occupied Long Island.In September 1945, Long Island was garrisoned by the Eighth Route Army and became an important sea route for transporting troops to the northeast.In October 1947, Kuomintang troops occupied Long Island.On August 12, 1949, the Chinese People's Liberation Army crossed the sea, liberated and stationed on Long Island.After the founding of the People's Republic of China, Long Island became a fortress area.The garrison and the local government should strengthen military and civil unity, carry out military and civil joint defense training, and achieve the goal of joint defense in peacetime and wartime.[2]
At the northern end of the Bohai Strait, Lushun belonged to the Tashi County in the Han Dynasty. It was named "Mashijin" in the Eastern Jin Dynasty, "Duli Town" in the Sui and Tang Dynasties, and "Shizikou" in the Yuan Dynasty. In the fourth year of Hongwu in the Ming Dynasty (1371), Zhu Yuanzhang, the first emperor of the Ming Dynasty, sent two generals, Ma Yun and Ye Wang, to land here from Penglai, Shandong, across the sea to recover Liaodong. Because the sea journey was smooth, Shizikou was renamed Lushunkou,Always used.In 1880, the Qing government set up the Beiyang Navy here, built a military port, built a fort, built a dock, and set up a camp. Lushunkou became a military fortress, and Lushun Military Port became one of the five famous military ports in the world at that time.As the main battlefield of the Sino Japanese War of 1894 and the Russo Japanese War of 1904, Lushun left an important page in the history of China and the world.Lushun was occupied by Russia for 7 years, enslaved by Japan for 40 years, and experienced many vicissitudes in the long-term colonial rule. It is known as "one Lushun port, half of modern history".On August 22, 1945, the Soviet Red Army stationed in Lvshun until it withdrew from Lvshun and returned home on May 24, 1955.On November 25, 1945, Lushun Municipal Government was established;After the establishment of Luda City in 1950, Lushun City was under the jurisdiction of Luda City;It was changed into Dalian in 1981, and Lushunkou became one of its districts.On July 1, 1996, Lushun was partially opened to the outside world.On November 21, 2009, the State Council and the Central Military Commission approved Lushun to officially open to the outside world.[41]
war
In the Qing Dynasty, from the eighth year of Xianfeng (1858 AD) to the tenth year of Xianfeng (1860 AD), the British and French allied forces passed through the Bohai Strait three times to occupy Beijing and Tianjin.In the 24th year of Guangxu (1898 AD), the Tsar Russia sent the warship "Dmitry Donsky" to occupy Long Island.After the signing of the Sino Russian Grand Concession Treaty and its renewal, the tsarist Russia also tried to force the Qing government to include Long Island in the Grand Concession.In the 26th year of Guangxu (1900 AD), the Eight Power Allied Forces invaded the Bohai Strait and occupied Beijing and Tianjin.During the Russo Japanese War in 1904 and the German Japanese War in 1914, the Japanese army used Long Island as a relay station to capture Lushunkou and Qingdao.[42]
At the end of August 1945, in order to ensure that the main force of Shandong moved into the northeast, Jiaodong Military Region set up a maritime headquarters, with Xu Shiyou as the commander in chief, and set up a maritime office of more than 30 people in Longkou to take charge of the maritime transport work in Longkou and Luanjiakou.In order to ensure the safety of maritime transportation, Xu Shiyou commanded the Jiaodong Military Region troops to eliminate the puppet troops on Changshan Island, control the Bohai Strait, set up military stations on the island, and collected food and grass as a springboard to march into the northeast, ensuring the safety and supply of maritime transportation.At the same time, more than 30 steamships and more than 140 sailboats were mobilized from Jiaodong to transport troops from the above two ports to the northeast day and night.[43]
In the Changshan Island Campaign on 25 July 1949, the front headquarters planned to launch a general offensive on the evening of 29 July. If the wind was not favorable, it could be postponed to the evening of 30 July and 26 July. A strong typhoon of level 12 hit the Bohai Strait, causing 104 heavy losses and 140 light losses, including 23 damaged steamships;33 sailors died and 32 were injured.[44]
