Read the information and introduce the geographical location and economic development conditions of my country's "Pearl River Delta", "Yangtze River Delta", "Yellow Triangle" and "Red Triangle"

Pearl River Delta. Located on the eastern coast of Guangdong Province, China, it is a general name for the large delta formed by the Xijiang and Beijiang rivers and the small delta formed by the Dongjiang river. It is a delta complex with radial branches. It is in the shape of an inverted triangle, with the base being a line from Sanshui City in the west, Guangzhou City in the east to Shilong, and the apex at Yamen Bay. It covers an area of ??approximately 11,000 square kilometers. The alluvial layer is thin, generally 20 to 30 meters. The ground is undulating and surrounded by hills, mountains and islands, accounting for 30% of the area. The central part is a plain, distributed in the south of Guangzhou City, the north of Zhongshan City, the east of Jiangmen, and the west of Humen. The average annual sediment load of the Pearl River system reaches more than 80 million tons, and the delta near the river mouth is still extending to the South China Sea. In the estuary area, it can extend by an average of 10 to 120 meters per year, 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 annual average temperature is 21-23℃, the coldest month, January, has an average temperature of 13-15℃, and the hottest month, July, has an average temperature of over 28℃. From June to October, there are often typhoons, rainfall is concentrated, and the weather is the hottest. The average annual precipitation is more than 1500 mm. The rainy season coincides with the high temperature season, the soil is fertile, and the rivers are crisscrossed, which is beneficial to agriculture. Rice output per unit area ranks among the best in China. There are more than 50 kinds of tropical and subtropical fruits, including lychees, citrus, bananas, pineapples, longans, star fruits, mangoes, grapefruits, lemons, etc. Three-dimensional agricultural structural forms such as mulberry-based fish ponds, fruit-based fish ponds, and sugarcane-based fish ponds have been developed and become a model of ecological agriculture in China. It has sugar, silk weaving, food, paper, machinery, chemical, building materials, shipbuilding and other industries, and is known as the Pearl of the South China Sea. The Yangtze River Delta starts from the Tongyang Canal in the north, reaches Hangzhou Bay in the south, reaches Zhenjiang in the west, and reaches the seaside in the east, including Shanghai, southern Jiangsu Province, northern Zhejiang Province and adjacent sea areas. With an area of ??approximately 99,600 square kilometers and a population of approximately 75 million, it is a vast plain. The coastline here is straight, the water is yellow and muddy, and there is an intertidal shoal about several kilometers to tens of kilometers wide. This urban agglomeration brings together strong strengths in industry, finance, trade, education, science and technology, and culture. It is instrumental in driving the economic development of the Yangtze River Basin, connecting domestic and foreign markets, attracting overseas investment, promoting industry and technology transfer, and participating in international competition and regional restructuring. plays an important role.

The Yangtze River Delta is the largest estuary delta in my country. It generally refers to the alluvial plain formed by the sediment of the Yangtze River east of Zhenjiang and Yangzhou. It is located in the southeast of Jiangsu Province, Shanghai City and the Hangjiahu region of Zhejiang Province. The apex of the Yangtze River Delta is near Zhenzhou Town, Yizheng City, with Yangzhou, Jiangdu, Taizhou, Jiangyan, Hai'an, and Zongcha as its northern boundary, and the Zhenjiang and Ningzhen Mountains, the eastern foot of Maoshan Mountain, the northern foot of Tianmu Mountain to the north shore of Hangzhou Bay. It is bounded to the west and south, and ends with the Yellow Sea and the East China Sea in the east.

The Yellow River Delta is a union of three delta systems: ancient, modern and modern. The terrain of the delta plain is low and flat, with an altitude of 11m in the southwest, the highest elevation of Lijin Nansong Township river beach plateau is 13.3m, the Laodong-Kenli area is 9-10m, the Luojiawu area is about 7m, and the lowest point in the northeast is less than 1m. The natural ratio Reduced from 1/8000 to 1/12000. The Yellow River bed is used as the framework in the area, forming the main watershed on the ground. The delta is a micro landform of alternating hills, slopes and depressions formed by the Yellow River's repeated diversions and breaches. It is distributed with different soil structures of sand and clay and various types of saline soil with varying degrees of salinization. These micro-landforms control the distribution of surface materials and energy, surface runoff and groundwater activities, forming water and salt accumulation areas centered on depressions, which are the main causes of "droughts, depressions, and alkaline slopes". Human activities (Yellow River diversion, construction of Yellow River embankments, reclamation, urban construction, highways, seawalls, oil extraction, etc.) are drastically changing the micro-topography of the area, but its basic framework is still clearly discernible.