period lasts 130–180 days. Location domain Yangquan City is located in the east wing of central Shanxi Province, with geographical coordinates of 112 °5 °114 °4 east longitude and 37 °40 °40 °38 °31 °north latitude. It is located in the west of the middle of Taihang Mountain, north of Dingxiang County and Wutai County of Xinzhou, and east of Pingshan County and Jingxing County of Shijiazhuang, Hebei Province. Southern Jinzhong Xiyang County, Jinzhong Shouyang County, Taiyuan Yangqu County; It is about 106 kilometers long from north to south and about 42 kilometers from east to west. the city has a total land area of 4559 square kilometers. Geomorphology Yangquan City is located on the eastern edge of the Loess Plateau and belongs to the eastern mountainous area of Shanxi Province. The landforms in the territory are mainly mountainous areas, while the rest are hills and plains. The mountains include nine mountains. On the northern city boundary is the Niudaoling Mountains, which is located at the junction of Zhoushan and Taihang Mountains. There are two mountains on the northwest boundary, which is the branch of Zhoushan. The rest of the mountains are arranged in two rows, east and west. The eastern train consists of four mountains, from north to south are the Baima Mountains, the Qiulin Mountains, the Mianshan Mountains and the Aishan Mountains. They belong to the middle of the Taihang Mountains, with peaks ranging from 700 to 1700 meters above sea level. Taihang Mountain is the boundary mountain of Hebei and Jin provinces, its eastern slope is steep, the foothills meet with the North China Plain, which is less than 100 meters above sea level; the western slope is gently inclined, and the mountains and hills are undulating. The western column consists of three mountains, namely, the Northern Mountains, the Southern Mountains and the Qiling Mountains. They have gone deep into the interior of the Shanxi Plateau, although the altitude is higher, but the ground fluctuation is slower than that in the east. Among the mountains, there are some intermountain basins, mainly Xiyan basin in the west, Yucheng basin in the middle and Pingding basin in the south. Hydrology Yangquan City, with the exception of 22 square meters in the west belongs to the Yellow River Basin, the rest belong to the Haihe River Basin. There are more than 60 rivers in the territory, of which 34 have