The history of the ocean

Our ancestors began to fish in the ocean in ancient times.

There are a lot of fish bones and piles of fish scales in the Neolithic Dawenkou cultural site discovered in jiaozhou city.

After identification, they belong to 3 orders and 4 families, such as giant salamander, barracuda, black snapper and blue snapper.

It shows that about 4000 ~ 5000 years ago, our coastal ancestors were able to hunt pelagic fish migrating between the ocean and the offshore, and people's understanding of marine fish habits has reached a certain level.

The word "sea" appears many times in The Book of Songs, which describes the situation of the Zhou Dynasty from1BC to the 6th century BC, and has the understanding that rivers live in the sea.

During the Western Han Dynasty, a route from the Pacific Ocean to the Indian Ocean was opened.

According to records, China's first tidal monograph appeared in the Three Kingdoms period ── Yan Gang's Tide Theory (lost).

During the Tang and Song Dynasties, tidal research in China reached a high level.

In the Ming Dynasty, the earliest existing regional marine fauna in China appeared ── Tu Benjun's China Fujian Series.

From 1405 to 1433, Zheng He made seven voyages to the Western Ocean in the Ming Dynasty, reaching the east coast of Africa south of the equator and Madagascar Island as far as possible, which was more than half a century earlier than Columbus's voyage from Europe to America (1492 ~ 1504), and he also far surpassed in navigation technology and understanding of the ocean.

Visible, in ancient times for a long time, China's understanding and utilization of the ocean is in the forefront in the world.

China's understanding and research on the ocean in ancient times mainly focused on four aspects: marine landforms, marine meteorology, marine tides and marine life.

At the same time, in order to make use of beaches and resist marine natural disasters, many achievements have been made in coastal protection and reclamation projects.

During the Warring States Period, Zou Yan of Qi (305-240 BC) put forward an ocean view of the earth-the theory of nine continents, and expounded the general trend of land and ocean distribution in the world.

He believes that the world is very big, with 8 1 piece of land as big as China, separated by the "blue sea", surrounded by the "Great Yinghai Sea", and the outside is the place where heaven and earth meet.

The "Pihai" and "Daying Sea" here are equivalent to today's "sea" and "ocean" respectively.

Ge Hong of Jin Dynasty put forward "Three Mulberry Fields in the East China Sea" in the book "Fairy Biography", which clearly expressed the idea of frequent changes between land and sea.

Terrain navigation was mainly used in ancient China, and the navigation books, needles and charts used included the navigable landforms on the route as detailed as possible, such as mountains, water potential, islands, reefs, harbors and seabed silt.

For example, the coastal sand map, coastal county map and Dengsai-Liaotu in Hu Zongxian's Chart Compilation in Ming Dynasty, the coastal map and nautical map of Wan Li in Zheng Kaiyang's Miscellanies, the coastal map and Zhenghe's nautical map in Mao's Wu Beizhi, etc.

Among them, Zheng He's nautical chart is the most detailed record of marine landforms, which is the peak of China's traditional cartographic method. 846 Chinese and foreign islands are accurately described and divided into island, continent, sand, shallow, stone pond, harbor, reef, moraine, stone, gate, continent, etc. 1 1 landform types.

The ancient seawalls in China are actually geomorphological maps of estuaries and coasts, such as Guancheng Fang's seawalls in Zhejiang and Zhai Junlian's seawalls in Qing Dynasty.

It can be clearly seen from the figure that the seawalls are not distributed continuously, and there are seawalls on the low-water coast and large beaches outside the pond. However, there are no seawalls in coastal mountainous areas.

Marine Meteorological Knowledge There were many books about marine meteorological knowledge in ancient China. Only 136 volumes are mentioned in the records of Han Dynasty, among which 18 volume is "The Comet of the Sun, Moon and Rainbow in the Sea".

During the Yuan and Ming Dynasties, people used five-character poems and four-character poems to express the weather experiences of sailors and fishermen.

For example, Zhang Xie's "East-West Studies" in the Ming Dynasty recorded that "dark clouds greet the sun, rain falls", "clouds win people's hearts, and the wind and rain turn" and "the rainbow breaks, and I will see you later. I don't know what happened. If the rainbow breaks, I will hang up early, not afraid of the wind. "

In maritime activities, wind is a crucial weather element, so the understanding of wind in ancient times is more profound.

Sailors and fishermen in ancient China knew how to predict ocean storms by various methods.

They write down the days of the year when there are often storms at sea. These days are called "storm days" or "hurricane days".

Some nautical books record the stormy days and their names throughout the year. For example, there are bad winds every month in Seeing the Wind.

Summarize the regularity of storm season and the frequency of storm days in different seasons, and find out the dangerous period and safe period of maritime activities.

One way to predict typhoons in ancient times was to observe ocean phenomena.

Long waves in the ocean move very fast. When the typhoon is still in the ocean, its long wave has spread to the offshore, forming swells, causing tidal anomalies, stirring up seabed silt, stinking seawater, abnormal behavior of marine animals and so on.

People call the above phenomenon "before the gods move, the sea gods move first", and this windless surge is called "wave shift" or "agitation".

China has long used wind and sails to assist navigation.

During the Eastern Han Dynasty, the use of monsoon navigation has been recorded in writing, and the southeast monsoon that appears after the rainy season every year is called "ship?" The wind. "

After the Tang and Song Dynasties, monsoon navigation was widely used.

Zheng He went to sea for seven times in Ming Dynasty, most of which set sail in winter and spring, and returned by southwest monsoon in summer and autumn, which showed that he had fully understood and utilized the seasonal variation law of wind direction and current in South Asia and North Indian Ocean.

During the voyage, they observe the appearance and displacement of the sun, moon and stars, the changes of wind direction, sky, clouds, haze and fog, temperature and waves, predict the changing trends of marine meteorology and hydrological tides, and ensure the safety of navigation.

The word "Dao" () appeared in China during the Shang Dynasty, and it was later interpreted as a synonym for "Chao".

It is now found that Wang Chong of the Eastern Han Dynasty gave the earliest scientific explanation to the tide phenomenon in China's ancient books.

In the book Lun Heng Xu Shu, he put forward the viewpoint that "waves rise and fall with the moon" and discussed the relationship between tides and the moon.

Yang Quan in the Western Jin Dynasty, Dou He in the Tang Dynasty, Zhang Junfang, Yan Su, Yu Jing and Shen Kuo in the Song Dynasty, Shi Boxuan in the late Yuan Dynasty and early Ming Dynasty, etc. Adhere to the development of Wang Chong's theory.

Ge Hong in the Eastern Jin Dynasty and Zhao Lu in the Tang Dynasty introduced the role of the sun in tides.

Dou Shumeng pointed out: "If you go with the flow, you must stay on the moon.

The moon and the sea push each other, and the sea and the moon phase period "; The calculation of tidal period is also very insightful; And draw the theoretical tide table "Doutao time chart" (figure 1).

Yan Feng explained the cause of the tide with the argument that "the latent phase induces the body to contract".

In the theory of tides, Zhang Junfang first determined that the daily delay of tides was 3.363 (100 in ancient times).

Yan Su, on the other hand, put forward the theory that tides correspond to the sun, and the yin is attached to the yang, and improved the calculation of theoretical tidal time, pointing out that the daily extension of tidal time can be divided into the maximum (30 days in the first lunar month) and the minimum (29 days), with the maximum being 3.72 and the minimum being 3.735.

Shen Kuo insisted on the theory of "according to the month" and gave a clear definition of "average * * * gap" at the earliest, and advocated modifying the regional tidal table with * * * gap.

In ancient China, there was also a profound understanding of the causes of tidal bore in trumpet-shaped estuary.

After refuting the superstition that Wu Zixu's ghost drove water to form a tidal bore, Wang Chong pointed out that the tidal bore only "overflowed" in the sea and only caused it after entering an almost small and shallow estuary.

Ge Hong put forward the "force" and "potential" of tides.

Zhao Lu pointed out that rivers and tides meet in narrow rivers, and they fight with each other to form tidal bore.

Yan Su pointed out that the tidal bore in Qiantang River was caused by the existence of sandbars in the estuary.

In Qing Dynasty, Zhou Chun noticed that the tides in Qiantang River can be divided into south tide and north tide.

The place where the two tides overlap happened to fall in Haining Pond, so Haining became a tidal scenic spot.

Tide gauges developed very early in China.

In the Eastern Han Dynasty, Ma Yuan built "Chaoxin Monument" on both sides of Qiongzhou Strait.

The existing Tidal Weather Map of Four Seasons in Zhejiang compiled by Lu Changming in the Northern Song Dynasty on 1056 was carved into a stone tablet and stood on the Qiantang River for crossing the river.

It is much earlier than the earliest tide table in Europe-the "London Bridge Tide Table" collected by the British Museum in13rd century.

There were also many tide gauges in Ming and Qing Dynasties.

The study of tides in ancient China reached its peak in the Song Dynasty.

Because there are many discussions on paleotide research, there are also many documents handed down, including dozens of monographs alone.

Among them, Tide Collection edited by Yu in Qing Dynasty and Tide Records edited by Zhai Junlian collected and preserved many ancient tidal works.

Understanding of Marine Life In ancient China, most of the understanding and research on marine life focused on the morphology, ecology, distribution and utilization of species.

Among them, many kinds of names are still in use today.

From ancient times to16th century, China's knowledge about marine life was mainly scattered in medical books and coastal local chronicles.

After 16, a monograph describing marine life appeared.

Huangdi Neijing, published in the 3rd century BC, mentioned the marine mollusks squid and abalone.

Shennong's Classic of Materia Medica in the 1 century recorded the morphology, origin, dietotherapy characteristics and utilization methods of six kinds of marine mollusks, such as Sargassum, Sargassum fusiforme and oyster.

Kouzong in Song Dynasty? #93; In Materia Medica Yi Yan, there are more than ten kinds of marine biological drugs, such as seal, clam, tortoise shell, oyster and squid.

There are many records about the ecological habits of marine life in ancient times.

Wu Renkangtai's Biography of Fu Nan mentioned that there was a rock at the bottom of coral island in the South China Sea, and corals were born on it.

The Biography of Foreign Bodies in Linhai by Shen Ying of the Three Kingdoms describes the biological rhythm of Zhao Chao (a small crab) synchronized with the tidal cycle.

In the Tang Dynasty, Youyang Za recorded that ship maggots "save wood and eat boats"; Hermit crabs are "exotic insects" ... they have no shells, but are packed in empty snail shells "; Flying fish "fish is a foot long, flying is lingyunkong, breathing at the bottom of the pool"; Squid "when you meet a big fish, don't put ink, measure a few feet and mix it up" and so on.

During the Ming and Qing Dynasties, many regional monographs on marine life appeared.

There are mainly the Fujian Sea Magazine written by Tu Benjun in Ming Dynasty and the Sea Magazine written by Guo Baicang in Qing Dynasty, which mainly record the marine life along Fujian coast.

In the Qing Dynasty, Hao Yixing and Li Tiaoyuan compiled the Record of Sea Fog and the Record of Rhinoceros respectively. The former recorded the marine life along the coast of Shandong, while the latter recorded the marine life along the coast of Guangdong.

Understanding and mastering the ecological habits of marine life promoted the development of ancient mariculture in China.

According to the discovered documents, oysters, pearl oysters and octopus were cultivated as early as the Song Dynasty, and the culture history of mullet is also very long.

Coastal engineering seawall storm surge disasters are very serious in China's coastal areas, especially in the southeast coast.

According to historical records, there are 2 13 times.

In order to protect life and property and develop agricultural production, seawalls were generally built in ancient coastal areas, among which Jiangsu and Zhejiang seawalls were the most magnificent and the technology was the most complicated.

Together with the Great Wall of Wan Li and the Grand Canal, it became the three major projects in ancient China.

The seawall originated very early.

In the Eastern Han Dynasty, Jiangsu and Zhejiang seawalls began to exist, and the scale of the Tang Dynasty was large.

Since then, the technology has been continuously improved, and there have been plate building method, bamboo cage compaction method, slope-lump method, vertical and horizontal stacking method and so on. , and the preparation of Tanghe, Tanshui and other supporting projects.

In the Qing Dynasty, Kang Yong mobilized a lot of manpower to build a stone pond from jinshanwei to Hangzhou on the basis of previous projects.

A permanent tidal sluice in the ancient estuary of China.

Putian Mulanbei, built in the Northern Song Dynasty, is a large-scale water conservancy project.

Before the dam was built, streams and seas were indistinguishable, with ebb and flow of tides, flooding and frequent droughts and floods in farmland.

After the completion of the dam, the salt tide was reduced, the fresh water was cut off, and more than 1 10,000 hectares of farmland were irrigated, which still plays a role in water conservancy.

Water City The ancient water city of Penglai, Shandong Province (Figure 2), with a small sea and calm waters, was an important coastal defense place in the Song, Yuan, Ming and Qing Dynasties and still exists today.

Founded in 1043 and expanded in 1376.

Shuicheng has wave platforms, breakwaters and sluices. They cooperate with each other to effectively curb the tides and waves flowing into the sluice.

The facade design of Shuicheng Wharf is also reasonable.