Topography, climate, soil, rivers and traffic in the Pearl River Delta.

The Pearl River Delta, referred to as the Pearl River Delta for short, is a delta formed by the impact of Xijiang River, Beijiang River and Dongjiang River, with an area of about 1 10,000 square kilometers. Generally speaking, its westernmost point is defined in Sanshui.

The Pearl River in China is a delta formed by alluvial deposits in the middle of Guangdong. It is composed of three small deltas alluvial by Xijiang River, Beijiang River and Dongjiang River, with an area of about 1. 1.3 million square kilometers. The Xijiang River and Beijiang River Delta account for110. There are more than 160 bedrock mounds in the delta, which were originally islands in shallow bay about 6000 ~ 2000 years ago. There is not much sediment in the Pearl River, and the annual total sediment is only 65438+ 100 million tons. Shallow bays with many islands are conducive to sediment stagnation, so the delta has developed rapidly in the past 2000 years. Canqiu is 300 ~ 500 meters above sea level and often becomes a beautiful scenic spot, such as Xiqiao Mountain, Wugui Mountain and Yashan Mountain.

Formerly known as Yuejiang Plain. The Pearl River Delta for short. Located in the eastern coast of Guangdong Province, China, it is the general name of the big delta formed by the confluence of Xijiang River and Beijiang River and the small delta formed by the confluence of Dongjiang River, and it is a delta complex with radial inlets. 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℃, with the highest Leng Yue 13 ~ 15℃ and the hottest month 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.

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 tropical climate in the Pearl River Delta is characterized by four unknown seasons, no snow in three winters, evergreen trees, evergreen fields and no frost. Zhu Kezhen said in his book "Special Climatology" that the tropics are places where "all seasons are summer, and it rains in autumn". He thinks that the south of Wuling Mountain is in the tropics. Therefore, the Pearl River Delta belongs to the tropical region.