Which city does Zhang Xi 'an County in Gansu belong to?

Zhang Xi 'an County, Gansu Province belongs to Dingxi City. According to Baidu map, Zhang Xi 'an County belongs to Dingxi City, Gansu Province. Because of its strategic position, it was considered as the "Xiguan" of the Han Dynasty, and it was renamed Wuyang County in the second year of Tang Dynasty. During the Hongwu period of the Ming Dynasty, it was renamed as Zhangxi 'an County because of "getting water to moisten the land, making wells convenient and enriching Qiang Bing". Zhangxi 'an County governs 3 townships 10, with an administrative area of about 2 164 square kilometers and a population of about 167300. Dingxi City is a prefecture-level city under the jurisdiction of Gansu Province. It is located in the northwest of China and the middle of Gansu Province. It is the intersection of the Loess Plateau, the Qinghai-Tibet Plateau and the West Qinling Mountains. The climate here is very different, and it is known as "the gateway of Lanzhou and the throat of Gansu". It is an important passage of the ancient Silk Road and the ancient Tang-Fan Road, and an important node city of the "Belt and Road" and the new land and sea passage in the west.