The construction of a series of horizontal levels built on a hillside, especially in upland or piedmont zones, in order to retain water and reduce soil erosion (C. Barrow (1999), Chen et al. (2007) PPG 31, 4); terracing technology is intimately related to irrigation and the availability of water. Ye and Yang (2002, J. Chongqing U., Nat. Sci. Ed. 25, 6, in Chinese, with English abstract) suggest that slopes of less than 8° are more suitable than steep slopes for changing into terraces. The terrace is a highly variable and only sometimes distinctive cultural artefact (Field (1966) DTC AD0679468).