The situation in the South China Sea is becoming more and more complicated, but the mainland has been able to deal with it calmly, because the mainland has completed the construction and upgrading of military facilities on Yongxing Island and Chenhang Island in Xisha Island, Fiery Cross Island in Nansha, Subi, Mischief, Nanxun, Dongmen, Huayang, and Chigua Island, among which Yongxing, Fiery Cross, Subi, Mischief and other islands will serve as nodes for patrolling, force projection, and long-range reconnaissance over Xisha and Nansha respectively because they have large runways, and Shenhang Island is gradually building the facilities required for helicopter deployment, which has greatly enhanced China's anti-submarine warfare capability in the region.
Generally speaking, the following conditions need to be met: first, the water depth conditions, that is, the water depth of the port area can accommodate large ships; second, the navigation conditions, that is, the smooth passage to ensure safe navigation; the third is the shelter conditions, that is, whether the atolls have a closed lagoon; and the fourth is the facility conditions, whether the area of the reef is sufficient for the construction of military camps and other facilities.
If the air force facilities are to be constructed, it is also necessary to meet the conditions of the runway site, that is, the reef has a sufficient length of space, and the runway direction should be consistent with the prevailing wind direction as much as possible, and the prevailing wind direction in the South China Sea is mainly northeast and southwest winds.
Combining the above conditions, the mainland garrisoned Mischief Reef in 1995 is simply a perfect atoll prepared for the construction of military bases, the Mischief Reef reef area of 10 square kilometers can build a large area of land, the lagoon area is about 36 square kilometers, the water depth of 20 meters ~ 30 meters can build a super-large shelter, the northwest reef is about 3,000 meters long, about 800m wide, and the southeast reef is 4,000 meters long More than 300 meters wide, these two parts are downwind and suitable for the construction of large airports, so the mainland does not hesitate to spend huge sums of money to build it into the largest island in Nansha.
Satellite image of Mischief Island
Mischief Island's 10 square kilometers of reef land creation ratio is close to 60%, forming a permanent land area of 5.66 square kilometers, the only shortcoming of Mischief reef island is that it is too far from Chinese mainland, because the construction of airport runway engineering is huge, the requirements for logistics conditions are very high, in this sense, the difficulty of building airports on each island and reef is inversely proportional to the distance to the Sanya base.
Under such extreme conditions, Mischief Island started on January 16, 2015, and completed the main island project on June 30, 2015, the construction period was only half a year, but 25.7 kilometers of concrete revetment were built, and the length of the island was equivalent to that of Xisha Qilianyu.
Aerial view of Mischief Island
According to a document issued by the China Oceanic Administration, the construction of such large artificial islands and reefs adopts the idea of "natural simulation", mimicking the natural process of storms and waves in the ocean, carrying coral gravel and other biological debris, and gradually evolving into maritime oases.
The impact of the "natural simulation" process on the ecological environment of coral reefs is local, temporary, controllable, and recoverable. In view of the possible impact of the construction of the project on the marine ecological environment, an expert group composed of academicians and experts in civil engineering, ocean engineering, marine ecology, environmental protection, geology and hydrology conducted scientific demonstrations.
"Nature simulation" blows and fills to form Subi Island
The formation process of Nansha islands and reefs is highly similar to that of Xisha Qilianyu, but the time is thousands or even tens of thousands of times shorter than that of Qilianyu.
The natural process of storms and waves in the ocean, the removal of coral sand and gravel and other biological detritus, and the gradual evolution into a maritime oasis, is still taking place on Qilianyu in Xisha, where a large number of new sandbanks have appeared in recent years.
Aerial photograph of Qilianyu
The islands and reefs on Qilian Island are basically elongated, just like a segment of Mischief Island, of which the longest and largest area is North Island, which is also known as "Changzhi, Long Island".
The North Island is located in the southeast of Zhaoshu Island, like a long arrow, the elevation and area are larger, about 8.2 meters high, 1500 meters long, about 300 meters wide, an area of about 0.4 square kilometers, surrounded by sand banks, the center of the island is a dry lagoon, the area accounts for about 1/2 of the island, there are beach rocks outcrops in the north and south, and coral sand limestone outcrops in the middle.
Satellite image of the North Island
The North Island has a typical butterfly-shaped landform, the island is surrounded by a piece of beach rock, inward is a sandy beach around the island, the inner side of the beach develops a sand bank with a high elevation, the terrain in the middle of the island is relatively low-lying, by the large number of birds gathered in the historical period, often with a relatively hard phosphorus hard rock layer, the habitat of birds provides a large number of nutrients for the development of island vegetation, resulting in a typical tropical coral island ecosystem in the Xisha Islands, and the vegetation cover is characterized by a single dominant vegetation community such as trees and shrubs distributed in a ring belt.
Sandy beaches and shrubs in the North Island
Of course, the Nansha islands and reefs are formed by rapid reclamation, and there will not be such a complex geology as the North Island. The surface layer of the North Island contains black humus coral sand sedimentary layer, the seabird droppings sedimentary layer containing coral sand in the middle and the coral sand sediment layer at the bottom, and the black humus, plant residues and medium to large coral sand particles can be seen on the surface, guano particles and bird bones are rare, and the central part contains a large number of granular guano droppings, bird bones, fish scales and medium to large coral sand particles. A large amount of carbonate biodetris is visible at the bottom.
Schematic diagram of lithological changes in the sedimentary profile of Qilianyu North Island
There are only 3 families with a total of 14 people on the North Island, forming a neighborhood committee, Huang Hongbo, director of the North Island Community Neighborhood Committee, and an identity is the head of the North Island Turtle Protection Station, the North Island of Qilianyu is one of the concentrated spawning grounds of sea turtles in the South China Sea, and every egg-laying season, groups of sea turtles will climb onto the island, and North Island is also known as "Turtle Island".
In the 90s of the last century, sea turtles were listed as national second-class protected animals, and illegal turtle fishing was curbed, but at that time, it was difficult to see turtles on the North Island to lay eggs, and "Turtle Island" was no longer worthy of its name.
After the establishment of Sansha City, no one is allowed to catch turtles and eat turtle eggs, and the all-round protection of turtles and turtle eggs has been carried out in an all-round way, through the unremitting efforts of Huang Hongbo's team and the fishermen on the island, coupled with the improvement of the island's ecological environment and the establishment of the turtle protection station, more and more sea turtles have gone ashore to lay eggs in groups, and the sea turtles that have come ashore to lay eggs have become a landscape in the North Island.
The infrastructure of the North Island is being rapidly renewed, with new settlements being built on the southern tip of the island and a shared port for helicopters.
Construction of the North Island New Area
North Island Deepwater Pier
The island is full of greenery, the water is crystal clear, sea turtles come ashore to lay eggs, and seabirds thrive...... The new appearance of the North Island in harmony with man and nature has initially appeared, and the North Island was briefly open for tourism in the past, and it is likely to be open for a long time in the future.
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