Hydrological response of loess slopes with reference to widespread landslide events in the Heifangtai terrace, NW China

Abstract In the Heifangtai terrace, NW China, flooding irrigation is common for the cropland production and has increased the groundwater table by 20–30 m over the past five decades. It is believed that excessive irrigation has induced a large number of loess landslides in this area. However, these loess landslides responses to hydrological changes have still not been well understood. Therefore, 43 boreholes and 51 2D Electrical resistivity tomography (ERT) profiles with a total length of 40 km have been investigated to analyze the hydrological characteristics for the whole terrace and characterize the effects of hydrological changes on the occurrence of different types of loess landslides. Our main findings are as follows: (1) Three groundwater domes are found in the center and eastern part of the Heitai terrace and the groundwater table is gradually rising in the whole terrace based on the ERT results. (2) The rising rate of groundwater table at the center of the terrace is twice greater than that at the margin of the terrace and it takes approximately 4 months for irrigation water to penetrate from the top surface to the saturated layer. (3) Landslide deposits could block drainage channels of groundwater, increase the localized hydraulic gradient and result in rising of local groundwater table at the edge of the terrace. (4) The resultant hydraulic gradient impels the groundwater from the center to seep out on the eastern and southern margins and new landslides are prone to occur in the main scarp of landslides with rising groundwater table. The type and magnitude of landslides are affected by groundwater seepage and movement. In order to fundamentally control the occurrence of landslides, effective drainage system and the restrained amount of irrigation water are needed.

[1]  L. Tham,et al.  The mechanism of soil failures along cracks subjected to water infiltration , 2014 .

[2]  R. Barker,et al.  Rapid least-squared inversion of apparent resisitivity pseudosections by a quasi-Newton method , 1996 .

[3]  Guan Chen,et al.  Characterizing hydrological processes on loess slopes using electrical resistivity tomography – A case study of the Heifangtai Terrace, Northwest China , 2016 .

[4]  E. Derbyshire,et al.  Geological hazards in loess terrain, with particular reference to the loess regions of China , 2001 .

[5]  Qiang Xu,et al.  Geometrical appearance and spatial arrangement of structural blocks of the Malan loess in NW China: implications for the formation of loess columns , 2018, Journal of Asian Earth Sciences.

[6]  Sai K. Vanapalli,et al.  Water infiltration characteristics in loess associated with irrigation activities and its influence on the slope stability in Heifangtai loess highland, China , 2018 .

[7]  Jean Poesen,et al.  Factors controlling the spatial distribution of soil piping erosion on loess-derived soils: A case study from central Belgium , 2010 .

[8]  P. Tarolli,et al.  Recognition of large scale deep-seated landslides in forest areas of Taiwan using high resolution topography , 2013 .

[9]  Qiang Xu,et al.  A chemo-mechanical insight into the failure mechanism of frequently occurred landslides in the Loess Plateau, Gansu Province, China , 2017 .

[10]  Y. Zhou,et al.  Laboratory characterization of rainfall-induced loess slope failure , 2017 .

[11]  J. Chambers,et al.  Three-dimensional geophysical anatomy of an active landslide in Lias Group mudrocks, Cleveland Basin, UK , 2011 .

[12]  Yanrong Li A review of shear and tensile strengths of the Malan Loess in China , 2017 .

[13]  Qiang Xu,et al.  Prediction of rainfall‐induced shallow landslides in the Loess Plateau, Yan'an, China, using the TRIGRS model , 2017 .

[14]  M. Pécsi Loess is not just the accumulation of dust , 1990 .

[15]  E. Tric,et al.  Multiyear time-lapse ERT to study short- and long-term landslide hydrological dynamics , 2017, Landslides.

[16]  Qiang Xu,et al.  Effects of rainwater softening on red mudstone of deep-seated landslide, Southwest China , 2016 .

[17]  V. Akulova,et al.  Loessial soils of Priangaria, Transbaikalia, Mongolia, and northwestern China , 2008 .

[18]  Y. Shang,et al.  Periodic recurrence and scale-expansion mechanism of loess landslides caused by groundwater seepage and erosion , 2019, Bulletin of Engineering Geology and the Environment.

[19]  A. Aydin,et al.  Formation of calcareous nodules in loess-paleosol sequences: Reviews of existing models with a proposed new "per evapotranspiration model" , 2018 .

[20]  Lei He,et al.  Influence of lixiviation by irrigation water on residual shear strength of weathered red mudstone in Northwest China: Implication for its role in landslides' reactivation , 2012 .

[21]  I. Smalley,et al.  Failure mechanisms in loess and the effects of moisture content changes on remoulded strength , 1994 .

[22]  Mathieu Javaux,et al.  Three-dimensional monitoring of soil water content in a maize field using Electrical Resistivity Tomography , 2012 .

[23]  Xuanmei Fan,et al.  Study on Early Recognition of Loess Landslides Based on Field Investigation , 2016 .

[24]  Jun Chen,et al.  A rapid loess flowslide triggered by irrigation in China , 2009 .

[25]  Qiang Xu,et al.  Application of electrical resistivity tomography for investigating the internal structure of a translational landslide and characterizing its groundwater circulation (Kualiangzi landslide, Southwest China) , 2016 .

[26]  Yang Yang,et al.  Origin and evolution of modern loess science – 1824 to 1964 , 2019, Journal of Asian Earth Sciences.

[27]  X. Pei,et al.  A study of a flowslide with significant entrainment in loess areas in China , 2017 .

[28]  The influence of changes in water content on the electrical resistivity of a natural unsaturated loess , 2013, 1303.5303.

[29]  Jef Caers,et al.  Uncertainty in training image‐based inversion of hydraulic head data constrained to ERT data: Workflow and case study , 2014 .

[30]  I. Jefferson,et al.  Some major events in the development of the scientific study of loess , 2001 .

[31]  G. Richard,et al.  Electrical resistivity survey in soil science: a review . , 2005 .

[32]  Qiang Xu,et al.  Distribution and failure modes of the landslides in Heitai terrace, China , 2017 .

[33]  Jie Liu,et al.  Controlling factors of loess landslides in western China , 2010 .

[34]  Yongxin Xu,et al.  Characterization of macropore structure of Malan loess in NW China based on 3D pipe models constructed by using computed tomography technology , 2018 .

[35]  Qiang Xu,et al.  Comparison of data-driven models of loess landslide runout distance estimation , 2019, Bulletin of Engineering Geology and the Environment.

[36]  S. Uhlemann,et al.  Electrical resistivity tomography determines the spatial distribution of clay layer thickness and aquifer vulnerability, Kandal Province, Cambodia , 2017 .

[37]  S. Romshoo,et al.  Micromorphological investigations of the Late Quaternary loess–paleosol sequences of the Kashmir Valley, India , 2015 .

[38]  Yanrong Li,et al.  Factors influencing development of cracking–sliding failures of loess across the eastern Huangtu Plateau of China , 2018 .

[39]  V. Lapenna,et al.  Digital photogrammetric analysis and electrical resistivity tomography for investigating the Picerno landslide (Basilicata region, southern Italy) , 2011 .

[40]  Miroslav D. Vujičić,et al.  Loess–palaeosol sequences in China and Europe: Common values and geoconservation issues , 2014 .

[41]  David Ottowitz,et al.  Permanent electrical resistivity measurements for monitoring water circulation in clayey landslides , 2016 .

[42]  Van Dam,et al.  Landform characterization using geophysics—Recent advances, applications, and emerging tools , 2012 .

[43]  Ling Xu,et al.  Landslides in a loess platform, North-West China , 2014, Landslides.

[44]  Xing Qi,et al.  Analysis of retrogressive loess flowslides in Heifangtai, China , 2017 .

[45]  M. Coop,et al.  The mechanics of a saturated silty loess with a transitional mode , 2017 .

[46]  Jianbing Peng,et al.  Shear wave velocity imaging of landslide debris deposited on an erodible bed and possible movement mechanism for a loess landslide in Jingyang, Xi’an, China , 2017, Landslides.