Taking Dujiangyan-Dayi-Hongya-Emei line as the boundary, there are significant differences in natural landscape and socio-economic conditions between the east and the west.
To the west of this line, the terrain is high, the mountains and valleys alternate with each other, the terrain is complex, and hydropower, forests and mineral resources are very rich. To the east of this line is the famous hilly basin in Chengdu Plain, with flat terrain, field buildings, rich products, concentrated population and towns, and developed industry and agriculture.
The area above Dujiangyan of Minjiang River is located at the junction of Qinghai-Tibet Plateau and Chengdu Plain. There are many fold belts with strong tectonic movement in geological structures, which are also part of the seismic active belts in the north and south of China. The regional geology is complex, and the exposed strata are mainly Cambrian-Devonian sandstone, phyllite and foreshock granite, Huanggang diorite intrusive rock mass, Devonian-Jurassic sandstone shale and limestone from top to bottom.
The basic earthquake intensity in this section is generally from ⅶ to ⅷ, but the intensity in the central area of Songpan Mao Wen earthquake is >: ⅸ.
Dujiangyan belongs to the western edge of Sichuan platform, with simple structure, only a few wide domes and small folds, and relatively flat strata. The exposed strata are mostly Jurassic and Cretaceous sandstone, shale and clay rock, with uneven lithology and many weak interlayers. The earthquake intensity in this area is very low, only V to VI degrees.
The upper reaches belong to the plateau climate zone, and the middle and lower reaches belong to the subtropical climate zone. The temperature and rainfall increase from north to south with the terrain.
In areas above 2500 meters above sea level, the annual average temperature is 5-9℃, and the annual average precipitation is 700-800 mm; Altitude 1500-2500m, annual average temperature113℃, annual average rainfall of 400-800mm；; The altitude is 750- 1500m, the average temperature for many years is above 15℃, and the average annual rainfall for many years is1000-1600mm; In areas below 750 meters above sea level, the average annual temperature is above 15℃ and the average annual rainfall is above1000 mm.
The Minjiang River Basin includes 36 counties in 8 cities, prefectures and states.
According to the data of the third census, the population is about150,000, accounting for 654.38+05% of the total population in Sichuan Province. The population is concentrated in the plains and shallow hills east of guanxian, Ebian and Mabian counties.
Minjiang River Basin is a multi-ethnic area, including Han, Tibetan, Yi, Qiang, Hui and Man.
There are abundant forest resources in the basin, and the total timber accumulation in Aba Prefecture in the upper reaches is 65.438+0.46 billion cubic meters, mainly in Lauraceae, Fagaceae and Lauraceae.
The forest area is also a natural zoo. There are many rare animals in Wolong Nature Reserve, Wenchuan, and many fur animals in plateau area.
Land resources are the most famous in Minjiang River Basin.
Paddy fields in plain areas can account for more than 90% of cultivated land, and are important commodity grain bases, mainly producing rice, wheat, corn, rape, sweet potato, vegetables, cotton, sugarcane and tea.
There are also abundant mineral resources in the basin, such as gold, lithium, beryllium, peat, glauberite, phosphorus and rock salt.
Songpan Zhanzhang Gold Mine, Meishan Glauber's Salt Mine and Mabian Phosphate Mine are all famous.
1952- 1982, the total industrial output value of the river basin grew at an average annual rate of 12%, and the total agricultural output value increased at an average annual rate of 3.3%, among which the machinery industry developed the fastest.
The traffic in the basin is developed, the middle and upper reaches of the river are networked by roads and railways, and the downstream is transported by water. Chengdu, Leshan, Yibin and other important cities control the upper, middle and lower reaches and become political and economic centers.
Chengdu is the capital of a province, Leshan belongs to Sanjiang, Yibin is an internationally famous wine city, living in the Yangtze River port, and has a bright future.
Minjiang River Basin (excluding Dadu River and Qingyi River) includes 32 cities and counties (districts) in Aba Prefecture, Chengdu City, Meishan City, Ya 'an City, Leshan City, Neijiang City, Zigong City and Yibin City.
By the end of 1999, the total population of the region was13.99 million, and the gross national product reached103.3 billion yuan.
Among them, the primary industry 19 1 billion yuan, the secondary industry 46.7 billion yuan, and the tertiary industry 37.5 billion yuan.
The upper reaches of Minjiang River belong to Aba Tibetan and Qiang Autonomous Prefecture, including Songpan, Heishui, Maoxian, Wenchuan and Lixian.
The upper reaches are rich in forest resources, with a total timber volume of 65.438+0.46 billion cubic meters. Mineral resources mainly include coal and iron ore.
The territory is mountainous and mountainous, with sparse arable land and population.
The local economy is dominated by agriculture, animal husbandry, forestry and electricity.
In recent years, hydropower development in Aba Prefecture has made great progress and has become a pillar industry of local finance.
Traffic along the river is mainly by highway, which is more convenient.
Farming has existed in the middle and lower reaches of Minjiang River since ancient times. After the completion of Dujiangyan by Qin Shu Garrison, Chengdu Plain became a "land of abundance", including 19 cities and counties, covering an area of nearly 8,000 square kilometers. It is an important grain and oil producing area in Sichuan with a good agricultural foundation.
High-tech industries and modern industrial and mining enterprises in this area are relatively developed, and transportation such as aviation, railways and highways extend in all directions.
Dujiangyan, which fully embodies the wisdom of working people in ancient China, has increasingly enhanced its functions and benefits, and its irrigation area has reached 6,543,800+000,600 mu. It is also the largest artesian irrigation area in Sichuan and the main source of urban water supply in Chengdu.
Chengdu is the capital of Sichuan Province, the political, economic, transportation and cultural center of the province, and one of the famous historical and cultural cities. Chengdu has become a new industrial base and a central city in western China.
At present, Chengdu is accelerating the pace of infrastructure construction, constantly enhancing its comprehensive service functions, and marching towards an international metropolis.
Minjiang River is a hilly basin below the mouth of Pengshan River. It is an important producing area of cash crops in Sichuan Province, with convenient land and water transportation and rich mineral resources, especially salt, coal, phosphorus and sulfur.
The main industries are salt making, wool spinning, coal, iron, chemicals, paper making, building materials, machinery and electricity.
There are many towns in the basin and the economy is prosperous. Chengdu, Leshan, Dujiangyan and Yibin have long enjoyed a good reputation.
The transportation in every town is very convenient.
These railways include Chongqing, Baocheng and Cheng Kun. There are national highways 108, 2 13, 3 17, 3 19, 32 1, trunk highways such as Sichuan-Tibet, Sichuan-Shaanxi, Chengdu-Chongqing, Sichuan-Yunnan and Chengdu-A, and provincial, county and township highways. The origin of Minjiang River water transport is very early. The voyage of Jiangkou-Leshan middle reaches is 1 15km, which can be used by 25t ships, and the load must be reduced by 40%-50% in dry season. The downstream voyage from Leshan to Yibin is 162km, with sufficient water, which can be used for 50-300-ton barges. The upstream current is so fast that it is difficult for the ship to pass.
Haizi, the size of the earthquake lake in the upper reaches, is closed to tourists now, but it has attracted the attention of people at home and abroad.
Some experts believe that there is no better place in the world to study the formation of earthquake lakes except beautiful scenery.
The steep cliffs and dilapidated ruins there still retain their original appearance after the strong earthquake 50 years ago, which is of great help to scientific investigation.
The famous Wolong Nature Reserve and Siguniang Mountain, located in the upper reaches of Yuzixi in the southwest of Wenchuan County, are ideal resorts for biological science research and mountain geological survey.
Dujiangyan is also a famous scenic spot.
The An Lan Bridge at the fish mouth leads people to the Erwang Temple on the mountainside of Lei Yu, overlooking the river, enjoying many ancient water control aphorisms left on the wall, and inspiring people's willingness to devote themselves to water conservancy in the beautiful scenery.
There is an ancient Fulong Temple on the pile of the bottle mouth, from which you can see the scene of Dujiangyan and Neijiang entering the water.
Many cultural relics preserved in the museum are enough to arouse people's nostalgia for the past.
Not far away, Qingcheng Mountain is famous for its "quiet world" and was once one of the birthplaces of Taoism in China. Taoist temples are everywhere on the mountain, especially the caves in the middle of the mountain.
The scenery behind Qingcheng Mountain developed in recent years is better than that in front. Along the way, there are deep valleys and dense forests, slow water flow, overlapping waterfalls and the sound of the waves accompanying people, which is a must.
From Dujiangyan to Chengdu, the famous cultural cities stand shoulder to shoulder and the scenic spots are invincible. There are mainly Wang Cong Temple in Pixian, Baoguang Temple in Xindu, Guihu Temple, Wuhou Temple, Caotang Temple, Wangjianglou, Baihuatan, Qingyang Palace, Zhaojue Temple and Wang Jian Tomb.
Down the river, there are famous sea mountains such as the Han Cliff Tomb in Pengshan, Susan Temple in Meishan, Thousand Buddha Rock in Jiajiang, Xiaoxihu Lake in Wu Tong and Leshan Giant Buddha. There are Cuiping Mountain, Thousand Buddha Rock, Daguanlou, Baita and other scenic spots in Yibin downstream.
Among these tourist attractions, there are also world-famous specialties. Wenchuan in the upper reaches is famous for its Sydney, apples and medicinal materials. Chengdu has had various famous snacks since ancient times, such as rice paper from Jiajiang, silk from Leshan, yamen seat in Yibin, rotten eggs and peanuts from Xufu, which have long been famous all over the world.
Leshan Giant Buddha is near Minjiang River. Here is a brief introduction.
This giant Buddha was originally carved in the Tang Dynasty. Known as "the mountain is the Buddha, and the Buddha is the mountain". It is tall and magnificent, and is known as the largest Buddha statue in the world.
The total height of the Giant Buddha is 7 1 m, the head length is14.7m, the ear length is 6.2m, the eye length is 3.3m, and the shoulder width is 24m. Located on the east bank of Minjiang River, facing Leshan City, Lingyun Mountain, where the Giant Buddha is located, is shaded by green trees, and there are three rivers at the foot of the mountain. The scene is vast and dry.