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.
Wuqi County, which belongs to Yan'an City, Shaanxi Province, is located in the northwest of Yan'an City, Dingbian County in the northwest, Zhidan County in the southeast, Jingbian County in the northeast, and Huachi County in Gansu Province in the southwest. The geomorphology belongs to the beam-shaped hilly and gully region of the Loess Plateau, with an elevation of 1233m between 1809 m. There are two major basins of Wuding River and Beiluo River in the territory, and the main structure of the terrain can be summarized as "Bachuan Erjian two mountainous areas". Since 1998, the policy of returning farmland to forests has been implemented, and the coverage rate of forest and grass has reached 49.6%. As of March 2019, Wuqi County has jurisdiction over 8 towns, 1 street office, 91 administrative villages and 8 urban communities, with a total area of 3791.5 square kilometers and a resident population of 152100 (2017), including an agricultural population of 106000. The oil industry is an important pillar of the economic development of Wuqi County.