title: Groundwater sapping as the cause of irreversible desertification of Hunshandake Sandy Lands, Inner Mongolia, northern China.
abstract: In the middle-to-late Holocene, Earth's monsoonal regions experienced catastrophic precipitation decreases that produced green to desert state shifts. Resulting hydrologic regime change negatively impacted water availability and Neolithic cultures. Whereas mid-Holocene drying is commonly attributed to slow insolation reduction and subsequent nonlinear vegetation-atmosphere feedbacks that produce threshold conditions, evidence of trigger events initiating state switching has remained elusive. Here we document a threshold event ca. 4,200 years ago in the Hunshandake Sandy Lands of Inner Mongolia, northern China, associated with groundwater capture by the Xilamulun River. This process initiated a sudden and irreversible region-wide hydrologic event that exacerbated the desertification of the Hunshandake, resulting in post-Humid Period mass migration of northern China's Neolithic cultures. The Hunshandake remains arid and is unlikely, even with massive rehabilitation efforts, to revert back to green conditions.
authors.affiliation: Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; xpyang@mail.igcas.ac.cn tree@unm.edu.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Earth and Planetary Sciences, University of New Mexico, MSC03 2040, Albuquerque, NM 87131; xpyang@mail.igcas.ac.cn tree@unm.edu.
authors.forename: Louis A
authors.initials: LA
authors.lastname: Scuderi
authors.affiliation: Institute of Earth Environment, Chinese Academy of Sciences, Xian 710075, China;
authors.forename: Xulong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute for Astronomy, University of Hawaii, Honolulu, HI 96822-1839;
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Scuderi
authors.affiliation: Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;
authors.forename: Deguo
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;
authors.forename: Hongwei
authors.initials: H
authors.lastname: Li
authors.affiliation: Geoluminescence Dating Research Laboratory, Department of Geology, Baylor University, Waco, TX 78798;
authors.forename: Steven
authors.initials: S
authors.lastname: Forman
authors.affiliation: College of Resources and Environment, Hebei Normal University, Shijiazhuang 050024, China;
authors.forename: Qinghai
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Institute of Archaeology, Chinese Academy of Social Sciences, Beijing 100710, China; and.
authors.forename: Ruichang
authors.initials: R
authors.lastname: Wang
authors.affiliation: Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China.
authors.forename: Weiwen
authors.initials: W
authors.lastname: Huang
authors.affiliation: Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China.
authors.forename: Shixia
authors.initials: S
authors.lastname: Yang
keywords: Holocene; climate change; geology; geomorphology; human activity