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.
Gucheng County, which belongs to Hengshui City, Hebei Province, is located in the southeast of Hebei Province, at the junction of Hebei and Shandong provinces and three cities. By 2018, with a total area of 941 square kilometers, there are 538 administrative villages in 11 towns and 2 townships, with a total population of 530000, including 410000 agricultural population and 910000 mu of arable land. Gucheng County is a sub-humid continental monsoon climate in the north temperate zone, with four distinct seasons and simultaneous rain and heat. The annual average temperature is 13.2℃. The annual sunshine time is 2608.5 hours and the annual sunshine rate is 59%. The average annual precipitation is 532 mm. The frost-free period for the whole year is about 190 days. In 2018, the GDP of Gucheng County reached 12.5 billion yuan, the total financial revenue was 1.14 billion yuan, the general public budget revenue was 666 million yuan, the investment in fixed assets was 8 billion yuan, and the total industrial output value was completed.