How big is Longnan, Gansu?
Longshang Jiangnan
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In the hinterland of the motherland, at the intersection of the western Qinba Mountains and the eastern edge of the Qinghai-Tibet Plateau, there is an ancient and Magical place. It has beautiful mountains and rivers, a mild climate, dense forests, abundant resources, abundant resources, and outstanding people. This is Longnan City in Gansu Province, which is the key point in the three provinces of Gansu, Shaanxi and Sichuan. It is known as "the key to Qinlong and the throat of Bashu" and is praised as "Long on the south of the Yangtze River".
Longnan City is located in the southern border of Gansu Province, connecting Shaanxi to the east, Sichuan to the south, Gannan Tibetan Autonomous Prefecture to the west, and Dingxi City and Tianshui City to the north. The geographical coordinates are 104°1′--106°35 east longitude. ′, between 32°38′ and 34°31′ north latitude. It is 221 kilometers long from east to west and 220 kilometers wide from north to south, with a total area of 27,900 square kilometers. The city governs 9 counties including Wudu, Dangchang, Wenxian, Chengxian, Kangxian, Huixian, Xihe, Lixian and Liangdang, 242 towns, 3,423 village committees, 540,000 households, and a population of 2.5 million. There are 21 ethnic groups in the territory, including Han, Hui and Tibetan, 7 ethnic townships, and a minority population of more than 50,000. The municipal government is located in Chengguan Town, Wudu District.
Various topography
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Longnan is located in the east-west direction of the West Qinling Mountains The Longnan Mountains, where fold belts are developed, are located in the transition zone of my country's terraced terrain. It transitions to the Gannan Plateau in the west, to the Longzhong Loess Plateau in the north, to the Sichuan Basin in the south, and to the Qinling Mountains of Shaanxi and the Hanzhong Basin in the east. The terrain of the city is high in the northwest and low in the southeast. Within the territory, mountains, deep valleys, hills and basins are distributed in sequence, alternating with each other, forming a unique, intricate and magnificent landscape. The Xili Mountains in the north present a loess landform of low mountains and wide valleys, with an altitude of about 1,800 meters; the Huicheng Basin in the east is between the North Qinling Mountains and the South Qinling Mountains, more than a hundred kilometers long and dozens of kilometers wide, with a hilly and wide valley terrain, with an altitude of 1,000 meters. meters; the southwest is high mountains and canyons, high mountains and deep valleys are connected at random, the contrast is obvious, "the head is steep and craggy, the ears are rough", the relative height difference is more than 1000 meters. From northwest to southeast, it starts from high mountains such as Dalaliang and Min'e Mountain (elevation 3,552 meters), passes through mid-mountain mountains such as Yindong Mountain (elevation 2,468 meters), Niutou Mountain (elevation 2,224 meters), and ends at Guantou Mountain (elevation 1,804 meters) and Jinzi Mountain. (1824 meters above sea level) and other low mountains, there are many mountains, steep cliffs, jagged peaks and jagged stone bones. The river valley is deep and narrow, with many deep meanders and rapids and waterfalls. In the canyon, there are steep cliffs on the high bank, as steep as a wall. Many narrow alluvial plains appear intermittently next to the valley, among which the Wudu Plain is nearly 50 kilometers long and less than 1 kilometer wide. Surrounding peaks: Dalaliang and Min'e Mountains are the watershed of the Yangtze and Yellow Rivers to the north, Toumaju Mountain is the border between Gansu and Shaanxi to the east, Congdi Mountain is adjacent to Gannan to the west, and Motianling is the boundary between Gansu and Sichuan in the south. The highest peak, Xionghuang Mountain, is 4,187 meters above sea level and is located in Tunzhai Township in the northwest of Wen County. The lowest point, Gugugou, is 550 meters above sea level. It is located in Zhongmiao Township in the southeast of Wen County. It is also the lowest point in Gansu Province.
Densely arranged rivers and streams
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Longnan is the only Yangtze River Basin region in Gansu. The territory is both mountainous and watery, and the water is as high as the mountains are. Between the high mountains and ridges, there are ups and downs of streams, waterfalls and springs everywhere. The city’s rivers are all part of the Jialing River system, with 48 first-level tributaries including the Bailong River and Xihan River, with a total length of 1,297 kilometers; 751 second-level tributaries, including the Baishui River and Minjiang River, with a total length of 4,756 kilometers; and 1,651 third-level tributaries with a total length of 4,313 kilometers; There are 1,312 fourth-level tributaries with a total length of 3,428 kilometers. Hundreds of rivers compete for their flow, and the river network is criss-crossed. The density of rivers reaches 0.5 per square kilometer.
Main river: The main stream of Jialing River flows through Liangdang and the southeastern part of Huixian County, with a course of 86.2 kilometers, an annual runoff of 2.2 billion cubic meters, and a drainage area of 2,556 square kilometers. The West Han River is a first-level tributary of the upper reaches of the Jialing River, flowing through 4 counties including Li County, Xihe, Cheng County, and Kang County. It has a flow length of 205.6 kilometers, an annual runoff of 1.67 billion cubic meters, and a drainage area of 9,569 square kilometers. The Bailong River is the largest tributary in the upper reaches of the Jialing River. It flows through three counties including Dangchang, Wudu and Wenxian. It has a course of 229.5 kilometers, an annual runoff of 9.38 billion cubic meters, and a drainage area of 13,200 square kilometers. Baishui River is a secondary tributary of Jialing River. It enters Shijiba Township in Wen County and merges into Bailong River at Guantouba in Yulei Township. It has a flow of 107.3 kilometers, an annual runoff of 3.43 billion cubic meters, and a drainage area of 3,040 square kilometers. Because the Bailongjiang River, the Qinling Mountains and the Huaihe River are located between 33° and 34° north latitude, they both belong to the area where the January 0°C isotherm passes. The rivers south of this line are not frozen. Therefore, the Bailongjiang River, the Qinling Mountains and the Huaihe River are both geographically southern in China. The natural dividing line with the north
Diverse climates with three-dimensional distribution
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Longnan genus East Asian monsoon climate zone. Due to the special geographical location and the influence of the mountain direction, the climate in the area is complex and diverse, with unique distribution. Both horizontal and vertical zoning are very obvious, forming a unique landscape of "one mountain has four seasons, and ten miles have different weather".
First, there is a huge temperature difference between the north and the south. From the southeast to the northwest, it transitions from the subtropical humid climate to the warm temperate humid climate, the temperate semi-humid climate and the alpine and humid climate. The annual average temperature is 5℃-15℃, the sunshine hours are 1700-2000 hours, and the active accumulated temperature is 2600-2600. -4600℃, annual precipitation of 450-1000 mm, and frost-free period of 166-285 days. Wudu, southern Wenxian County and southeastern valley area of Kangxian County....