Describe the topographic features of Longnan city

Longnan is located in Longnan mountainous area, where the east-west fold belt of the West Qinling Mountains is developed, where the Qinling-Bashan Mountain area, the Qinghai-Tibet Plateau and the Loess Plateau meet, and the terrain of China is in the transition zone from the second level to the third level. The western part transits to Gannan Plateau on the northern edge of Qinghai-Tibet Plateau, the northern part transits to Longzhong Loess Plateau, the southern part transits to Sichuan Basin, and the eastern part is connected with West Qinling and Hanzhong Basin. Longnan is high in the northwest and low in the southeast, with an average elevation of 1 1,000 m. The western Qinling Mountains and Minshan Mountains extend from the east and west to the whole territory respectively, forming a complex terrain with mountains, valleys and basins alternately.

Xili Mountain in the north of Longnan presents a loess landform with low mountains and wide valleys, with an altitude of 1800 meters. Huicheng Basin in the east is located between the northern Qinling Mountains and the southern Qinling Mountains, with a length of more than 100 kilometers and a width of several tens of kilometers, with a hilly and wide valley topography and an altitude of about 1000 meters.

The alpine valleys in the southwest of Longnan are interlaced with mountains and deep valleys, with obvious contrast, and the relative height difference is more than 1000 meters.

Mountain peaks around Longnan: Dalaliang and Min 'e Mountains to the north of the Yangtze River and Yellow River watershed, Toumaju Mountain in Longdong and southern Shaanxi, Congdi Mountain in Gannan to the west, and Motianling Mountain in Longnan and Sichuan. Xiong Huang Mountain, the highest peak, is 4 187 meters above sea level, located in Tunzhai Township, northwest of Wenxian County. Guanzigou, the lowest point, is 550 meters above sea level, located in Zhongmiao Township, southeast of Wenxian County, which is also the lowest altitude in Gansu Province.

According to the overall difference of landforms and the different degree of regional cutting, the whole territory of Longnan can be divided into three types of landforms:

Shallow-middle cutting shallow mountain hilly basin landform area, medium-deep cutting medium-high mountain landform area and full cutting medium-high mountain landform area.