Tianjin is located in the lower reaches of the Haihe River, across the banks of the Haihe River. It is the traffic throat of Beijing's railway to Northeast China and East China and the port of ocean transportation. It is called "the hub of rivers and seas" and "the gateway to Kyrgyzstan". North-south length 189 km, east-west width 1 17 km. The land boundary is 1 137 km long and the coastline is 153 km long. The hinterland is vast, radiating to North China, Northeast China, Northwest China 13 provinces, municipalities and autonomous regions, and facing Northeast Asia externally. It is the largest coastal open city in northern China. The geological structure of Tianjin is complex, and most of it is covered by Cenozoic sediments. The terrain is dominated by plains and depressions, with low mountains and hills in the north, and the altitude gradually decreases from north to south. The highest in the north, with an altitude of1052m; The lowest in the southeast, 3.5 meters above sea level. The highest peak in the city: Jiushan Peak (elevation1078.5m). The general outline of the landform is high in the northwest and low in the southeast.
Tianjin has three kinds of topography: mountains, hills and plains, with plains accounting for about 93%. Except the mountainous area bordering the southern foot of Yanshan Mountain in the north, the rest are alluvial plains, and the mountainous area in the north of Jixian County is a low mountain and hill below 1000 meters above sea level. Near the mountain is an inclined plain composed of alluvial fans, which is fan-shaped The southern part of the inclined plain is alluvial plain, and the southeastern part is coastal plain. Tianjin straddles the banks of the Haihe River, which is the largest river in northern China. There are more than 300 tributaries, with the upstream length exceeding 10 km, which join the North Canal, Yongding River, Daqing River, Ziya River and South Canal near the middle reaches. Five rivers join the Haihe River at Sanchakou near Tianjin Jingang Bridge and enter the sea from Dagukou. The main stream is 72 kilometers long, with an average river width of 100 meter and a water depth of 3-5 meters. Historically, this river was navigable for 3000 tons of seagoing ships.
There are 19 first-class rivers flowing through Tianjin, with a total length of 1095.438+0 km. There are also six artificial rivers, including Ziya New River, Liu Du Reduction River, Machang Reduction River, Yongding New River, Chaobai New River and Returning Home New River, with a total length of 284.5438+0 km. There are 79 secondary rivers, with a total length of 1363.4km and deep canals 106 1, with a total length of 4578km. Tianjin has also transferred water from the Yellow River to Tianjin many times, and there is a certain amount of groundwater.
The Luanhe River Diversion Project is a large-scale water conservancy project built in Tianjin in the 1980s, which transfers water to Tianjin and delivers water to Tianjin every year/kloc-0.00 billion cubic meters. Tianjin is rich in groundwater, karst fissure water in mountainous areas, with the best water quality and low salt content. The flow rate of spring water is generally 7.2- 14.6 tons/hour, and it can reach 720-800 tons/hour in rainy season. There are three large reservoirs in the city with a total storage capacity of 340 million. mineral
There are more than 20 kinds of metal, nonmetal and fuel minerals in Tianjin. Metal minerals and nonmetallic minerals are mainly distributed in the mountainous areas in northern Tianjin. Metal minerals mainly include manganese, boron, manganese, gold, tungsten, molybdenum, copper, zinc and iron, among which manganese and boron are not only discovered for the first time in China, but also rare in the world. Non-metallic minerals mainly include cement limestone, barite, stromatolite, marble, natural oilstone, purple mud and medical stone, all of which have high mining value.
Cement stone is the dominant mineral among nonmetallic minerals in Tianjin. There are five proven deposits in industrial reserve, and the ore bodies occur in the limestone of Tieling Formation in Jixian system of Mesoproterozoic, containing 48% ~ 50.7% Cao. The five proven deposits in industrial reserve are Dongying Fang, Zhuanshan, Tieling, Laohuding and Yushan, with proven reserves of 654.38+0.8 billion tons. Marl minerals have become an important resource of Tianjin cement industry.
Zisha clay mineral in Jixian County, Tianjin is located in two layers of illite shale in Chuanlinggou Formation and Hongshuizhuang Formation of Middle-Upper Proterozoic. Among them, the Yili shale of Chuanlinggou Formation is distributed in the first line from Xia Ying Town to Xiaogang Township, with a total length of 12km and a width of 2 km, with an exposed area of 24 square kilometers and an open-air reserve of 700 million tons. Illite in the two layers is a large clay deposit, which is a high-quality mineral raw material for purple sand pottery.
associated gas
Tianjin is rich in oil and gas resources. Fuel mines are mainly buried in Bohai Bay Plain and continental shelf, with oil, natural gas and coal-formed gas. Tianjin has two major oil fields, Bohai and Dagang, which are the key oil and gas fields developed by the state. The proven oil reserves are 4 billion tons, the oil field area is 100 square kilometers, the natural gas geological reserves are 150 billion cubic meters, and the coal field area is 80 square kilometers. Tianjin coastline is located in the west of Bohai Sea, starting from Qikou in the south and reaching Jianhekou in the north, with a length of 153 km. Marine resources are characterized by tidal flat resources, marine biological resources, seawater resources and marine oil and gas resources. The beach covers an area of more than 370 square kilometers and is being developed and utilized. Marine biological resources, mainly plankton, swimming organisms, benthos and intertidal organisms. Seawater is a famous salt-producing area with high salinity since ancient times, and it has the largest salt field in China. Seawater desalination has great potential to solve the shortage of fresh water. Marine oil and gas resources are abundant, and 45 oil-bearing structures have been discovered, with considerable reserves.
Tianjin has inexhaustible sea salt resources. The coastline of Tianjin is about153km long, and Luchang Yantian, the most famous sea salt producing area in China, is located here. In 2005, the annual output of crude salt was 2.3 million tons, accounting for110 of the national total sea salt production. Vegetation can be roughly divided into 1 1 species, such as coniferous forest, mixed coniferous and broad-leaved forest, deciduous broad-leaved forest, shrub grass, meadow, halophyte, swamp vegetation, aquatic vegetation, desert vegetation, artificial forest and farmland planting plants.
As of September 2006, there are 497 species of wild animals in Tianjin, including 73 species of national key protected animals. Among the wild animals in the city, weasels, wolves and badger pigs account for 4 1 species, birds such as domestic swallows, sparrows and seagulls account for 389 species, amphibians such as toads account for 7 species, reptiles such as domestic snakes and turtles account for 4 1 species, and fish such as green eels account for 41species. Tianjin is rich in land resources. Among them, the cultivated land area is 485,600 hectares, accounting for 40.7% of the city's total land area; The garden area is 37,324 hectares, accounting for 3.13%; 34,227 hectares of forest land, accounting for 2.87%; 594 hectares of grassland, accounting for 0.05%; Residential area and industrial and mining land 2 18345 hectares, accounting for18.33%; The traffic land is 32,937 hectares, accounting for 2.76%; The water area is 3 15089 hectares, accounting for 26.43%; The unused land is 67,845 hectares, accounting for 5.69%. Of the total land area, the state-owned land is 50 16800 mu, accounting for 28.06%; Collective land12,862,800 mu, accounting for 7 1.94%. The land of the whole city, except the mountains and hills in northern Jixian County, is developed on deep sediments. There are 1, 2 1.4 square kilometers of wasteland and beaches to be developed in the coastal areas of the lower reaches of Haihe River, which are ideal places for developing petrochemical and marine chemicals.