Where are the Pearl River Delta and the Yangtze River Delta?

Formerly known as Yuejiang Plain. Located in the eastern coast of Guangdong Province, China, it is a delta complex with a radial estuary, which is the general name of the large delta formed by the simultaneous alluvial of Xijiang River and Beijiang River and the small delta formed by the alluvial of Dongjiang River. It is an inverted triangle, with the bottom line starting from Sanshui City in the west, Guangzhou City in the east, and Shilong, with the apex at Yamenwan. The area is about 1. 1 10,000 square kilometers. Alluvium is thin, generally 20 ~ 30 meters. The ground fluctuates greatly, surrounded by hills, mountains and islands, accounting for 30% of the area. The central part is plain, distributed in southern Guangzhou, northern Zhongshan, eastern Jiangmen and western Humen. The annual sediment transport capacity of the Pearl River system is more than 80 million tons, and the delta near the estuary is still extending to the South China Sea. Hekou District can extend 65,438+00 ~ 65,438+020 meters every year, which is one of the key reclamation areas in China. The delta has a subtropical climate, which is warm and humid all year round. The annual average temperature is 2 1 ~ 23℃, the coldest 1 monthly average temperature 13 ~ 15℃, and the hottest July average temperature is above 28℃. There are frequent typhoons from June to 10, with concentrated rainfall and the hottest weather. The annual average precipitation exceeds1500mm. The rainy season is synchronized with the high temperature season, with fertile soil and rivers, which is beneficial to agriculture. The yield per unit area of rice is among the best in China. Tropical and subtropical fruits include litchi, citrus, banana, pineapple, longan, carambola, mango, grapefruit and lemon. Three-dimensional agricultural structures such as mulberry-based fish ponds, fruit-based fish ponds and sugarcane-based fish ponds have been developed, which has become a model of ecological agriculture in China. There are sugar, silk, food, paper, machinery, chemicals, building materials, shipbuilding and other industries, known as the pearl of the South China Sea.

Physical and geographical characteristics of the Pearl River Delta

The Pearl River Delta is a tropical delta, because its geographical location is south of the Tropic of Cancer (for a small delta), and for a large delta, it is also between 23 40 ′-265 438+0 30 ′ north latitude, that is, most of it belongs to the tropical range. From the climate point of view, the big delta also belongs to the tropical region (see Zhu Kezhen et al. Phenology, 1962). Landform development also has this feature, and the vegetation landscape is more influenced by it, developing into tropical monsoon rainforest vegetation. Moreover, because the northern part of the delta is the mountainous area of northern Guangdong, it plays a barrier role to the cold current from the north, so that tropical vegetation can invade the mountainous area north of the Tropic of Cancer along the valley.

The Pearl River Delta region includes Guangzhou, Shenzhen, Zhuhai, Foshan, Jiangmen, Zhongshan, Dongguan and Huicheng, Huiyang, Huidong and Boluo in Huizhou, and Ruizhou, Dinghu, Gaoyao and Sihui in Zhaoqing. The whole area accounts for 23.4% of the total area of the province, and the population accounts for 31.4% of the total population of the province (1.994). In recent years, GDP has accounted for about 70% of the province's GDP. The Pearl River Delta is one of the fastest growing areas in China. With the rapid development of economy, the social development in this area presents the characteristics of high degree of rural industrialization and rapid process of urban-rural integration.

Seen from the topographic boundary of the Pearl River Delta, Luoping Mountain Range is the dividing line between the west and the north, that is, the Xijiang River Valley is west of Luoping Mountain Range, which is customarily called the western mountainous area of Guangdong. To the north of the mountain range is the Beijiang River system, or the mountainous area of northern Guangdong. Luofushan area in the east is the eastern boundary of the delta.

■ Yangtze River Delta

China Yangtze River and Qiantang River are alluvial deltas where they enter the sea. Include Jiangsu province, southeastern Shanghai and northeastern Zhejiang. It is a part of the middle and lower reaches of the Yangtze River. It covers an area of about 50,000 square kilometers. The apex of the delta is in Zhenjiang and Yangzhou, and the north reaches Xiaoyangkou. South bank of Hangzhou Bay. The elevation is mostly below10m, and the low hills (such as Huishan, Tianpingshan, Yushan and Langshan) are scattered, with an elevation of 200-300m. The annual sediment discharge of the Yangtze River is 400-900 million tons. In general, 28% of the sediment is deposited in the Yangtze River, and in some years it is as high as 78%. The delta continues to extend to the sea. The ancient sand mouths in Changzhou, Changshu, Taicang, Jinshan and other counties south of the Yangtze River are mostly 4 ~ 6 meters above sea level; The ancient sand mouth in Yangzhou, Taizhou, Taixing and Rugao, north of the Yangtze River, is 7-8 meters above sea level. The ancient sand mouths in Jiangnan and Jiangbei developed gradually after the highest sea level stabilized in the late glacial period. By about 2000, the north bank sand mouth extended to Liaojiaozui, and the south bank sand mouth extended to the southeast with the mainstream of the Yangtze River and connected with the mouth sand mouth of Qiantang River. Sediment continues to accumulate, advancing annually 1958 ~ 1973. It belongs to the northern subtropical monsoon climate, with abundant rainfall, criss-crossing waterways and dotted lakes, and is known as a water town and a country. The land is fertile, and agriculture mainly produces rice, cotton, wheat, rape, peanuts, silk, fish and shrimp. It is one of the most densely populated areas in China. There are many important towns in the lower reaches of the Yangtze River and on both sides of the Shanghai-Nanjing line, such as Shanghai, Suzhou, Changzhou, Wuxi, Zhenjiang, Yangzhou, Taizhou and Nantong. Among them, Shanghai is the largest industrial and commercial city in China and a world-famous foreign trade port, while Suzhou and Wuxi are scenic spots and emerging industrial cities.