Yanshan

Yanshan

Yanshan is one of the famous mountains in northern China. It's a strategic place. It starts from Wanquan in Zhangjiakou and Yanghe in Huaian in the west, ends at Shanhaiguan in the East, connects Bashang Plateau in the north, Qilaotu mountain and Nuluerhu mountain in the north, and is separated from Taihang Mountain by Guangou in the southwest. On the south side is Hebei Plain, with large height difference. Luanhe river cuts off the mountain to form xifengkou, Chaohe River cuts off Gubeikou and so on. It has been a north-south traffic channel since ancient times. In ancient and modern wars, it was often a place for military strategists.

It is 420 km long from east to west, 200 km wide from north to south, with an altitude of 600-1500 M. donghouding, the main peak, is 2292.6 m above sea level.

In a broad sense, Yanshan refers to the mountains south of Bashang Plateau, north of Hebei Plain, east of Baihe Valley and west of Shanhaiguan. In a narrow sense, it refers to the mountains south of the narrow range, boluonuo, Zhongguan and dachangzi.

There are Miyun reservoir, Panjiakou Reservoir and other yanxiadu No.1 building base reservoirs in mountainous areas.

Donghouding, the main peak, is 2292.6 meters above sea level; haituoshan, the second highest peak in Beijing, is 2241 meters; on its south side, xiaohaituoshan, the third highest peak in Beijing, is 2198 meters.

On the east side of the mountain range are Wuling Mountain, 2118 meters above sea level; Jiushan mountain, the highest peak in Tianjin, 1078 meters above sea level; baxianzhuozishan mountain, the second highest peak in Tianjin, 1052 meters above sea level; Dushan mountain, 1846 meters above sea level. The highest peak of Qinhuangdao city is Zushan, 1428 meters; the second peak is in the north of Qinhuangdao City, Laoling, 1424 meters. The altitude of the whole mountain range is less than 2300m, and donghouding is about 10m less than the peak of Dongling Mountain in Beijing.

Geology and geomorphology

The Yanshan Mountains are steep. The terrain is high in the northwest and low in the southeast. It is gentle in the north and steep in the south, narrow in the valley, broken in the surface, and numerous in rain cracks and gullies. The Chaohe River is divided into East and West sections. The eastern section is mostly low mountains and hills, with an altitude of less than 1000 meters. The vegetation is luxuriant, with shrubs and weeds, and a vast forest area. The west section is a middle and low mountain area, generally over 1000 meters above sea level, with sparse vegetation and shrub and grassland. Among the mountains are Chengde, Huairou, Yanqing, Xuanhua and other basins. There is a great wall built along the ridge, and the situation is dangerous. Xifengkou, Gubeikou, Huanghuacheng, Juyongguan, dongfangkou, dushikou and Zhangjiakou are important passes of the Yanshan Great Wall. They have been important channels from the north of Yanshan to the North China Plain since ancient times. There are Beijing Chengde, Beijing Tongliao, Beijing Baotou railway and highway through.

The geological structure of Yanshan mountain is extremely complex, with typical karst stalactite strata, more limestone and quartzite, thousand shale, slate, marine erosion rock, sedimentary rock, etc. There are dozens of kinds of Yanshan stone, including wajing stone, yellow wax stone, tens of thousands of stone, dolomite and so on. There are many kinds of ornamental stones, such as gray green, brown, Chu red with green, pure white, blue gray with yellow, etc., with vivid texture, rich variety, simple texture, dignified luster and rich forms, especially pictographic objects.

Yanshan Mountains (generalized) belong to Inner Mongolia platform anticline and Yanshan subsidence zone. It rises steadily in the north and subsides in the south. The Sinian strata in the Yanshan subsidence zone are well developed, and the thickness of Jixian and Zunhua in the sedimentary center is more than 10000 meters. At the end of Mesozoic, strong tectonic movement took place and folded into mountains, so this orogeny is called "Yanshanian Movement".

Yanshan is an eroded and denuded middle mountain with east-west trend. The altitude is 500-1500 meters. It is high in the north and low in the south, and falls to below 500 in the south, becoming a low mountain and hill. There are Yunwu Mountain, Wuling Mountain, Dushan mountain, Jundu mountain and so on. The main peak is 2293 meters east of houding. There are many basins and valleys in the mountains, such as Chengde, Pingquan, Luanping, Xinglong, Kuancheng and other valleys, and Zunhua, Qianxi and other basins, which are the main agricultural areas in the Yanshan Mountains.

The Yanshan movement initially established the modern geomorphology of eastern China. The Neocathaysian tectonic system proposed by Li Siguang consists of three uplift zones and three subsidence zones. Except for the first and second subsidence zones, they all began to develop in the Yanshanian period.

For example, as the southern part of the second uplift belt, the southeast hills were fully developed in this period, which was a much higher mountain area at that time. As the third uplift zone, the nearly north south mountain area of Greater Khingan Range, Taihang Mountain, Xuefeng mountain and other separated landforms of the first and second steps of the Chinese mainland began to develop.

Climatic characteristics

Yan District is located in the warm temperate continental monsoon climate zone. The average annual temperature is 6-10 ℃, the average temperature in January is - 12-6 ℃, and the average temperature in July is 20-25 ℃. The duration above 10 ℃ is 195-205 days, and the active accumulated temperature is 2600-3800 ℃.

The southern foot of Yanshan mountain is one of the rainy areas in Hebei Province. The annual precipitation is about 700 mm, and the water erosion is strong.

Water system

The water system around Yanshan is developed and the rivers are widely distributed, mainly including Yanghe River, Chaobai River and Luanhe River. Most of the rivers intersect with the mountains and cut through the mountains to form north-south traffic channels. They are also important passes, such as Gubeikou and xifengkou. The easternmost Shanhaiguan Pass is the throat connecting northeast and North China. Miyun reservoir, Guanting reservoir and Panjiakou Reservoir are three large reservoirs with water storage capacity of more than 2 billion cubic meters.

Characteristic products

Vegetation distribution

The zonal vegetation in Yanshan is deciduous broad-leaved forest (mainly Quercus), mixed with warm coniferous Pinus tabulaeformis forest. The deciduous broad-leaved forest below 700 meters is composed of Quercus mongolica, Quercus liaotungensis, Quercus Quercus, Quercus variabilis, Quercus, etc. 700-1500 m is coniferous and broad-leaved mixed forest, and the tree species are fir, birch, birch, etc. The coniferous forest is 1500-2000m long, with Larix principis rupprechtii and Pinus thunbergii, but mainly secondary forest. The gully and piedmont alluvial platform are suitable for fruit tree planting, which is one of the important distribution areas of deciduous fruit trees in China. Rich in chestnut, walnut, pear, hawthorn, grape, apple, sand fruit, apricot and other dry and fresh fruit. Among them, chestnut, walnut and hawthorn are famous at home and abroad.

mineral resources

As one of the oldest mountains in the world, Yanshan Mountains are rich in mineral resources, including iron ore (Qian'an, Luanxian), coal mine (Luanxian), lime (the whole region), and gold mine (Pinggu, Zunhua), which occupy a large proportion in China.

wild animal

The continuous strengthening of ecological construction has improved the natural environment, and the macaque group that has disappeared in Yanshan for many years has reappeared in Xinglong County, Hebei Province.

Rhesus monkey, also known as rhesus monkey, is a second-class protected animal in China. It is mainly distributed in tropical areas of South Asia and Southeast Asia. In China, it is mainly distributed in the south, but less in the north. Up to the 1960s and 1970s, there were only macaques distributed in Liuliping area of Xinglong County in Yanshan area. Liuliping is considered to be the northernmost boundary of macaque natural distribution. But since 1970, there has been no activity of macaques in Liuliping. On October 22, 1987, workers of Liuliping state-owned forest farm found a dead macaque. Since then, no macaque has been seen in Yanshan.

Since the summer of 2003, macaques have reappeared in Liuliping Forest Park, Sanchakou village and Huayuan village in Xinglong County. Macaques return to their "Hometown" in Yanshan and are welcomed and protected by local villagers.

Xinglong County is located in the northeast of Hebei Province, which belongs to Yanshan mountain area. In order to "protect" the fengshui of the eastern Mausoleum of the Qing Dynasty, the emperors of the Qing Dynasty banned Xinglong for more than 270 years, making the ancient trees towering and macaques swarming. But in the last century, because of the war and development, the vegetation of Xinglong County was destroyed. A number of ecological construction projects, such as the greening project around the capital and the harnessing project of the small watershed in the upper reaches of the Luanhe River, were implemented in Xinglong County. In 1999, this county was also designated as a key county for ecological environment construction in China. The local wildlife protection department said that ecological construction has effectively improved the natural environment and provided good conditions for macaques to reproduce.

Human history

From a historical point of view, there are big and small Yanshan. Dayanshan, the Yanshan Mountains in the north of Beijing, was named later; xiaoyanshan, located in Fangshan District in the southwest of Beijing, is northwest of Fangshan Chengguan Street and Yanshan Office. Maoershan, dafangshan and Fenghuangling were once known as dafangshan. Xiaoyanshan is the earliest Yanshan, roughly named in the Shang Dynasty. Later, due to the Northern Migration of Yandu, dayanshan got its name.

In the earliest oracle bone inscriptions in China, it is recorded that there was a country in Beijing that became Yan. In the Shang Dynasty, there were only two countries with the surname Yan in this area. Therefore, the use of "Yan" in Yanshan area is natural.

Yanshan district is located 40 kilometers southwest of Beijing. According to Zhoukoudian, the hometown of Peking man, it is only 5 kilometers. Neolithic relics have been found in the area, proving that human activities existed between 500000 and 10000 years ago. According to the literature, in the early history, this generation was the area where Shanrong, Sushen and other minorities lived.

Yanshan extends eastward from Chaobai River valley into an arc and reaches the coast of Bohai Sea. It is the natural barrier of northeast and North China. Jundu mountain in the north of Beijing belongs to the Yanshan Mountains. Taihang Mountain is a big mountain from northeast to southwest. After entering Beijing, it becomes the west mountain. Its higher peaks are Baihua Mountain, Maoer Mountain and so on. Yanshan area is backed by Maoer Mountain, Lingshan mountain, Baihua Mountain, Maoer Mountain and so on, which are collectively referred to as Dafang mountain. And in the Warring States period

Chinese PinYin : Yan Shan