Geography physics compulsory course for senior one 1 (Hunan Education Edition) is mentioned ~
China has not only a vast land area, but also a vast ocean, many islands and a long coastline.
Part of the coastline of Chinese mainland starts from the mouth of the Yalu River in the northeast and extends southward to the mouth of Beilun River in Guangdong, with a length of about 18000 km. The vast sea area and long coastline not only provide convenience for overseas transportation, but also the shallow sea and coastal zone are rich in animal and plant resources and mineral resources.
China coastal natural conditions are extremely complex and diverse, but they also have obvious characteristics. From the point of geomechanics, the outline of the coast, like the whole eastern continent, is basically controlled by two groups of X-shaped fault structural systems in the northeast and northwest. Therefore, in the coastal zone, no matter from the large-scale coastal contour or from the specific large and small bays, headlands, straits and large and small estuaries, they are basically distributed along this X-shaped fault structure (Figure 54). For example, the Yellow River estuary extends northeast, while the Yangtze River estuary and the Pearl River estuary extend slightly northwest; Hangzhou Bay is northeast, while Jiaozhou Bay, Sanmen Bay and Sansha Bay extend slightly northwest. It is particularly noteworthy that the coastal contours of exposed bedrock areas, such as Liaodong Peninsula, Shandong Peninsula and Zhejiang-Fujian coastal areas, are consistent with the Neocathaysian (northeast) structure that controls the eastern part of China.
The coastline south of Hangzhou Bay is almost parallel to the northeast structural line of Zhejiang and Fujian hills. However, from southern Fujian to Guangzhou, it gradually turns to the northeast, and the coastline extends in a fairly regular arc. This is due to the joint action of Nanling banded tectonic system, which distorts Zhejiang-Fujian tectonic system.
Some large rivers, such as the Yangtze River, the Yellow River and the Liaohekou accumulation plain, or some straits, such as Qiongzhou Strait, are located in the fault block subsidence area. However, some coastal islands, such as Changshan Islands on the east side of Liaodong Peninsula, also reflect the influence of this fault to some extent.
A: Strengthening here means that the effect becomes obvious, and it can be associated that one of the basic functions of wetlands is to protect the rocks on the shore. Many kinds of plants grow in the wetland. These wetland vegetation can resist the impact of waves, typhoons and storms and prevent coastal erosion. At the same time, their roots can fix and stabilize banks and coasts and protect industrial and agricultural production along the coast. If there is no wetland, the coast and river bank will be destroyed by waves.
I hope it helps you ~!