Topography, climate, soil, rivers and traffic in the Pearl River Delta.
The Pearl River in China is an alluvial delta at the place where it enters the sea in central Guangdong. It consists of three small deltas alluvial by Xijiang River, Beijiang River and Dongjiang River, covering an area of about 11,3 square kilometers. Among them, Xijiang River and Beijiang River Delta account for 1/1. There are more than 16 bedrock mounds in the delta, which were originally islands in shallow bays about 6, ~ 2, years ago. There is not much sediment in the Pearl River, and the total sediment is only 1 million tons per year. The shallow bay with many islands is conducive to sediment stagnation, so the delta has developed rapidly in the past 2, years. Canqiu is 3 ~ 5 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. Referred to as the Pearl River Delta. Located in the eastern coast of Guangdong Province, China, it is a delta complex with radial inlets, 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 and Guangzhou City in the east to Shilong, and the apex in Yamenwan. It covers an area of about 11, square kilometers. Alluvium is thin, generally 2 ~ 3 meters. The ground fluctuates greatly, surrounded by hills, mountains and islands, accounting for 3% of the area. The central part is a plain, distributed in the south of Guangzhou, north of Zhongshan, east of Jiangmen and west of Humen. The average annual sediment transport of the Pearl River system is more than 8 million tons, and the delta near the estuary is still extending to the South China Sea. In the estuary area, it can stretch 1 ~ 12 meters every year on average, making it one of the key reclamation areas in China. The delta has a subtropical climate, which is warm and humid all year round. The average annual temperature is 21 ~ 23℃, the coldest January is 13 ~ 15℃, and the hottest July is above 28℃. From June to October, there are often typhoons, with concentrated rainfall and the hottest weather. The average annual precipitation is more than 15mm. The rainy season is synchronized with the high temperature season, with fertile soil and vertical and horizontal 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 position is south of the Tropic of Cancer (in terms of small delta), and in terms of large delta, it is also between 23 4' and 21 3' north latitude, that is, most of it belongs to the tropical range. From the climate point of view, the great delta also belongs to the tropical region (see Zhu Kezhen et al. Phenology, 1962). Landform development also has this feature, and vegetation landscape is more influenced by it, and it develops into tropical monsoon rainforest vegetation. And because the northern part of the delta is the mountainous area of northern Guangdong, it acts as a barrier to the cold current coming 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. According to Zhu Kezhen, in his book "Special Climatology", the tropics are places where "it is summer at all seasons and autumn when it rains". He thinks that the south of the Wuling Mountains is in the tropics. Therefore, the Pearl River Delta is within the tropical zone.