What are the topography and geographical features of Dazhou and its products?

Dazhou City is a prefecture-level city in Sichuan Province. It was renamed and established from the original Dachuan area with the approval of the State Council in 1999. Dazhou is also known as "Dacheng". It is located in northeastern Sichuan, at the southern foot of Daba Mountain. It is a populous city, an agricultural city and an important industrial town in Sichuan Province. It is known as the "Pearl of Eastern Sichuan", "China's Gas Capital" and "Hometown of the Ba People". There is also a large area of ??gardens, and it has been rated as "Garden City of Sichuan Province" and "Environmental Protection Model City of Sichuan Province". At present, Dazhou is actively striving to become a "National Sanitary City, a National Garden City, a Civilized City in Sichuan Province, a Model City with Beautiful Environment in Sichuan Province, and a Forest City in Sichuan Province." Dazhou City has a total area of ??16,591 square kilometers and governs 1 municipal district and 5 County, 1 county-level city. During the "Twelfth Five-Year Plan" period, Dazhou City will become one of the eleven megacities developed in Sichuan.

The terrain of Dazhou City is high in the northeast (Daba Mountain District) and low in the southwest (basin). Hilly area). The highest point is Daduanbao, Jichangdazhou Township, Xuanhan County, with an altitude of 2458.3 meters; the lowest point is Tianguan Village, Wangxi Township, Qu County, with an altitude of 222 meters. Daba Mountain is located in the north of Xuanhan, Wanyuan, with Mingyue Mountain and Tongluo Mountain and Huafu Mountain lie between them from north to south, dividing the city into three parts: mountainous areas, hills, and flat areas. Mountains account for 70.70% of the area, hills account for 28.10%, and flat areas in the north account for 1.20%. , the mountains are steep, forming mid- and low-mountain landform units; the central and southern parts are relatively gentle, forming the Pingping Valley landform unit.

Geomorphic features

Daba Mountain

Jialing River. The watershed of the Han River and the geographical boundary between the Sichuan Basin and the Hanzhong Basin. In the narrow sense, Daba Mountain only refers to Micang Mountain and Daba Mountain in the border areas of Sichuan, Shaanxi and Hubei provinces. It stretches for more than 500 kilometers from east to west, so it is called Qianli Bashan for short. Guangdong Daba Mountain is the general name for the border mountains of the four provinces of Sichuan, Daba Mountain, Gansu, Shaanxi and Hubei, including Motian Ridge extending to the west of Micang Mountain and Shennongjia Mountain extending to the east of Daba Mountain. Between the Sichuan platform synclines, due to the control of the two major structural lines in the north and south, the mountains are in the form of a series of parallel fold belts composed of regular anticlines and synclines, but the east and west parts are slightly north and the middle part is slightly south, so it may It is called the Daba Mountain arc-shaped fold belt. The strata are ancient and mainly composed of limestone, dolomite, metamorphic rock, and sandstone. The first two have karst landforms such as multi-peak clusters, caves, and underground rivers. The famous ones are Guangyuan Longdong, Wangcang Huangyang Cave, Tongjiang Zhongfeng Cave, etc. are composed of hard crystalline limestone, which is thick and majestic after rising and eroding. The altitude is about 2,000 meters, Wuxi Taiping Mountain is 2,797 meters, and the highest Shennongjia in Hubei is 3,105.4 meters. p>Huaying Mountain

Huaying Mountain originates from the southern foot of Daba Mountain. It is the boundary mountain between the parallel folded ridges and valleys in eastern Sichuan and the hills in central Sichuan. It runs from northeast to southwest and spans Dazhou, Guang'an, Chongqing and Neijiang, Zigong, Luzhou, Yibin and other cities, with a total length of 325 kilometers, because "the top of the mountain looks like Qiong Yao scattered on the ground, and the mountain is covered with crystal jade", so it is named Huaying Mountain from the south of Qu County to Guang'an District. To the northeast and south to Baoding at the junction of Linshui County and Huaying City, it extends into Yubei District and Hechuan District of Chongqing City. Huaying Mountain is about 70 kilometers long in Guang'an City, generally 6 kilometers wide, and 9 kilometers at its widest point. From Linshui Temple Liangzi to Baoding, it is the highest part of the entire Huaying Mountain, with an altitude of 1,704 meters. It is also the highest peak in the Sichuan Basin. Huaying Mountain is rich in mineral deposits, dense forests, and a wide variety of animals. In 1993, Huaying Mountain was listed as a provincial scenic spot with tourism development value.

Tongluo Mountain

Tongluo Mountain is the second mountain range in the parallel fold ridge and valley area of ??eastern Sichuan. It starts from the northern end of Leiyinpu Mountain in Da County in the north, runs from northeast to southwest, spans Dazhou, Dazhu County, Linshui County and Chongqing's Changshou District, Yubei District, Nan'an District, Banan District, Qijiang District and other counties, and ends at Tiantai Mountain on the north bank of Qijiang River. It has a total length of 260 kilometers, a width of 5 kilometers to 10 kilometers, and an altitude of generally 600 meters to 1,000 meters. The highest peak, Wanfeng Mountain, is in Long'an Town, Linshui County, with an altitude of 1,054 meters. Because the Yangtze River cuts across the mountains east of Chongqing City, it forms the Tongluo Gorge. The water in the gorge hits the rocks like the sound of a gong, so it is named Tongluo Mountain. Tongluo Mountain enters Linshui County from Da'ancao, Dazhu County, and passes through the towns of Xinzhen, Taihe, Lengjia, Chang'an, Liangban, Jiufeng, Yaofeng, Yaotan, etc., with a length of about 65 kilometers, including Wanfeng Mountain to Xian The Yingshan section has steep mountains and deep valleys. It is the highest section of Tongluo Mountain. The axis of the anticline has been eroded for a long time, taking the shape of "one mountain, two ridges and one trough".

The trough is dotted with residual hills, dissolved depressions, and sinkholes, and has a typical karst landscape. Valleys such as Daping, Guirencao, Liangban, and Changjiacao have flat and open terrain, densely populated areas, contiguous fertile fields, and rich products. There are many karst caves on both sides of the trough and valley, especially the area from Jiufeng to Yaofeng Yulinhe Small Three Gorges. There are more than 30 caves, among which Jiulong Cave, Moon Cave, Lanjia Cave, Hejia Cave, Lion Cave and Fairy Cave have the best views.

Mingyue Mountain

Mingyue Mountain is the third mountain range in the parallel folded valley area of ??eastern Sichuan. It starts from Kaijiang County in the north, runs from northeast to southwest, and spans Dazhou, Liangping, and Dazhu. , Linshui, Dianjiang, Changshou, Yubei District and other counties and districts, ending at Yongxingchang, Banan District. The total length is 232 kilometers, the width is 4 to 6 kilometers, and the general altitude is 700 to 1,000 meters. The Yangtze River cuts across the mountains between Yubei District and Banan District, forming a canyon. There are "round holes like a full moon" on the cliffs on the gorge bank, so it is called Mingyue Gorge, and the mountain is named after the gorge.

Hydrology

The rivers in Dazhou City mainly belong to the Jialing River system, a tributary of the Yangtze River. They originate from Daba Mountain and are distributed in a dendritic shape from north to south. The Qianhe River, the Zhonghe River and the Houhe River merge into the Zhouhe River and the Bahe River merge into the Qujiang River in Sanhui Town, Qu County, flowing 300 kilometers southward into the Yangtze River. There are 53 rivers with a drainage area of ??more than 100 square kilometers and 15 main rivers with a drainage area of ??more than 1,000 square kilometers. There are 9 navigable rivers in the country, namely Qujiang, Zhouhe, Bahe, Qianhe, Houhe, Zhonghe, Tiexihe, Qingxihe and Linggangxi. Basically, they are composed of Qujiang, Zhouhe, The waterway transportation network of the main stream of the Ba River covers four counties (cities) in the city. The navigable mileage of each river varies, and the carrying capacity is less than 100 tons.

Qujiang

Qujiang belongs to the Jialing River water system. The Jialing River has many tributaries, the two largest being Fujiang River and Qujiang River. The Qujiang River originates from Daba Mountain, also known as Diving, and flows through Bazhong and Dazhou to Sanhui Town in Qu County, where it is called Qujiang. The total length is 720 kilometers. The Qujiang River starts from Sanhui Town in Qu County and runs from the north to the territory of Qu County. In the south, it flows through 8 districts, towns, and 21 townships, including Sanhui District, Tuxi District, Liuxi District, Linba District, urban suburbs, Qujiang Town, Xiandu District, and Langya District, among which there is Yongxing River. , Guixi River, Liujiang River, Zhongtan River and other tributaries flow into it. It exits from Wajiaotan, Langya Township, the southernmost part of Qu County, and enters Qinlao Village, Xiaoxi Township, Guang'an County. It runs diagonally through the middle of Guang'an County from northeast to south-west, passing through Hengsheng District, Stalagmite District, Guange District, and Daishi District. , Kwuntang District, Xiexing District, Guangfu District and Huaying City, from Laojun Village, Hualong Township, Guangfu District, to Zhonghe District and Luodu District, Yuechi County. It originates from the Linxi River, Luodu River, and Xinmin River in the Huaying Mountains, and merges into the main stream of the Qujiang River. It exits at the Shanxikou of Shunliangzhai Village, Sailong Township, Yuechi, enters the northeastern part of Hechuan District, and flows through the Wei River. Xianglu, Pier, Mosquito Dragon, Ancient City, Sunjia, Weixi, Shuanghuai, Laitan, Xiaomio, Baisha, Damu, Fangbei, Safety, etc. The 18 townships of Guandu, Yujia, Pujia, Qujia and Tanzi flow into the Jialing River at the mouth of Quhe, 7.5 kilometers north of Hechuan County.

Tongchuan Bridge

The Han-Chongqing Highway was the shortest route for transporting Soviet anti-Japanese aid materials to Chongqing. It was known as the "East Sichuan-Shaanxi Road" at the time. It is more than 90 kilometers shorter than Sichuan-Shaanxi Middle Road and more than 270 kilometers shorter than Sichuan-Shaanxi Road. Therefore, the Nationalist Government of Wuhan ordered the construction in February 1938. Opened to traffic in 1941, it made a major contribution to the transportation of materials during the Anti-Japanese War. Due to the construction of a new bridge on the original site. It was bombed in 1996.

Climate Characteristics

Dazhou City has a subtropical humid monsoon climate type. Due to the complex terrain, regional climate differences are large. Low mountains, hills, and river valleys below 800 meters above sea level have a mild climate, with warm winters, early springs, hot summers, and cool autumns, four distinct seasons, and long frost-free periods; low and mid-mountain areas with an altitude of 800 to 1,000 meters have a warm, cool, humid climate, and delayed rejuvenation. , summers are scorching hot, autumn cools early, and winters are cold and long; in Zhongshan mountainous areas with an altitude of more than 1,000 meters, light and heat resources are insufficient, the cold period is long, and spring cold and autumn frost are very prominent. The city is rich in heat resources, with rain and heat in the same period. The annual average temperature is between 14.7 degrees and 17.6 degrees, and the frost-free period is about 300 days. The city has abundant rainfall, with the average annual rainfall ranging from 1076 to 1270 mm. There are cold waves and low temperatures in spring, droughts, floods, strong winds, and hail in summer, and continuous rain in autumn.

Among the 2,158 species of plants identified in the city's census, 1,652 species are available for medicinal purposes, and more than 500 species are now included in the standard. There are more than 30 bulk varieties, which sell well in domestic and foreign markets.

Dahurica dahurica, safflower, lily, and black plum produced in Da County; Coptis chinensis, Codonopsis pilosula, Dalizi, and Magnolia officinalis produced in Xuanhan County; Cyperus rotundus and mountain plants produced in Kaijiang County; Tangerine peel, Codonopsis pilosula, Bupleurum, and Eucommia ulmoides and Gastrodia elata. Angelica dahurica and Ligusticum chuanxiong produced in Qu County are all bulk products. Among them, Gastrodia elata, Eucommia ulmoides, Cortex cypress, Magnolia officinalis, Shouwu, etc. are quite famous