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.
Zhoukou City, a prefecture-level city under the jurisdiction of Henan Province, is located in the southeast of Henan Province, located in the hinterland of Huang-Huai Plain, Fuyang City, Anhui Province to the east, Luohe City and Xuchang City to the west, Zhumadian City to the south, and Kaifeng City and Shangqiu City to the north. Zhoukou Special area was established in 1965 (later changed to Zhoukou area). Zhoukou City was revoked with the approval of the State Council in 2000. By the end of 2018, Zhoukou City had jurisdiction over two districts, seven counties and one county-level city, with a total area of 11959 square kilometers and a resident population of 8.6778 million. Zhoukou traffic extends in all directions, highway, railway, waterway transport intertwined into a network, forming a highway, railway, waterway trinity traffic pattern. The Shaying River has been a navigable channel since ancient times, with two major wharves of Zhoukou and Liuwan, which enter the Huaihe River and join the Yangtze River. Sand