A mesa is an isolated, flat-topped elevation, ridge or hill, which is bounded from all sides by steep escarpments and stands distinctly above a surrounding plain. Mesas characteristically consist of flat-lying soft sedimentary rocks capped by a more resistant layer or layers of harder rock, e.g. shales overlain by sandstones. The resistant layer acts as a caprock that forms the flat summit of a mesa. The caprock can consist of either sedimentary rocks such as sandstone and limestone; dissected lava flows; or a deeply eroded duricrust. Unlike plateau, whose usage does not imply horizontal layers of bedrock, e.g. Tibetan Plateau, the term mesa applies exclusively to the landforms built of flat-lying strata. Instead, flat-topped plateaus are specifically known as tablelands.
Wuzhong City, located in the middle of Ningxia, was originally the resident of Gu Lingzhou City and Jinji County, located in the hinterland of Ningxia Plain, high in the south and low in the north, and belongs to the arid and semi-arid climate area in the middle temperate zone. The city has a total area of 21400 square kilometers and has jurisdiction over two districts, one city and two counties. By the end of 2018, the total resident population of Wuzhong City was 1.4154 million, an increase of 11600, or 0.83%, over the end of last year. According to the annual report of the Public Security Bureau, the total registered population at the end of the year was 1.4378 million. Wuzhong City has been an important passage of the Silk Road since ancient times, an important node city of the New Silk Road Economic Belt, and a regional trade city along the New Eurasian Continental Bridge. The domestic road network is dense and convenient, with 4 railways and 5 highways running through the city area, Wuzhong-Zhongwei intercity railway and Yinxi high-speed railway Wuzhong hub station.