What's the difference between muddy coast, sandy coast and reef coast? How to be applied by human beings?

Type of coast: coast, according to its shape and origin, can be roughly divided into bedrock coast, sandy (gravel) coast, muddy coast and biological coast.

Bedrock coast, also known as harbor coast, is mainly formed by geological tectonic activities and wave action. It is characterized by steep terrain, winding coastline and rapid water depth.

Sandy (gravel) coast, also known as accumulation coast, is formed by plain materials being transported to the coast and transformed and accumulated by waves or wind. It is characterized by loose sand (gravel), narrow beach and steep slope.

Muddy coast, also known as plain coast, is mainly formed by rivers bringing a large number of fine sediments into the sea under the action of tidal currents and waves. It is characterized in that the beach material components are mostly clay, silt, etc. The coastline is straight and the terrain is flat.

Biological coast includes coral reef coast and mangrove coast. The former is formed by the accumulation of tropical reef-building coral remains; The latter consists of mangrove plants and muddy tidal flats. Biological coasts only appear in tropical and subtropical regions.

The coast of Hainan Island belongs to biological coast, some of which are mangrove coast and some are coral reef coast.

coral reef coast

Coral is an advanced coelenterate and cannot move in the ocean.

Coral has strict requirements on the place where it grows.

The optimum seawater temperature should be above 20℃

. It lives an honest and clean life and can't stand unclean sea water. It doesn't like salt, and it doesn't like fresh sea water.

It is required that the salinity of seawater should be kept at about 35‰.

.

It likes the fresh and rich oxygen in seawater. The depth of its growth does not exceed 40-60 meters.

If you don't meet the above conditions, you can't be sheltered. If the original comfortable living environment deteriorates, then fight to the death, which really has the spirit of "I would rather die than live". At the estuary, there are no coral reefs growing there due to the invasion of fresh water and sediment. In the bay where the sea is too calm, the coral community grows very slowly and is on the verge of death because of lack of oxygen. Because corals have strict requirements on growth conditions, corals can only grow in tropical and subtropical seas with necessary conditions and temperate regions affected by warm currents. So,

Coral growth boundary is mainly in the sea area between 28 degrees south latitude and 28 degrees north latitude on both sides of the equator.

Many dead reef-building coral skeletons are cemented with some shells and calcareous algae to form a large porous calcareous rock mass, which is as hard as a reef, so it is called a coral reef. Coastal coral reefs formed in shallow water constitute a beautiful coral reef coast. Coral reef coast is one of the important coastal types in China. Coral reefs are widely developed in the coastal areas of Guangdong, Guangxi, Taiwan Province and Hainan south of the Taiwan Province Strait, as well as Dongsha, Xisha, Zhongsha and Nansha Islands.

According to the rock characteristics, coral reefs can be divided into two types: coral reef limestone and coral clastic rock. The former is a huge coral reef group, which accumulates into reefs in the original place and is not moved. The latter is the situation that the fragments and debris of primary reefs or reef-building corals are transported to other places for deposition after being destroyed to form reefs. In the process of coral debris formation, there are some complete shells and fragments, calcareous algae, and even some gravels with different lithology and size, so the composition of coral debris rocks is complex, unlike coral reef limestone.

The main component of some coral reefs is not coral skeleton, but granular debris of many other kinds of calcium-containing animal shells and plants living on coral reefs. The composition of coral reefs in the Caribbean is mainly calcareous algae, which gives people a deeper understanding of coral reefs.

Coral reefs form a unique coral reef coast. So, where are their roots? Coral reef is not a rootless tree, it also needs a fixed place. Most of the coral reefs on the north coast and west coast of Hainan Island are fixed on basalt on the seabed. Rocks are the best appendages of coral reefs. Besides rocks, coral reefs can also be built on fine sand and muddy bases. There is a sediment interlayer between the coral layers of the Great Barrier Reef in Australia, and some coral reefs in Indonesia were formed on silt. Whether it is rocks, fine sand or silt, it can hold up beautiful "coral reef buildings".