Possible mechanism of the formation of the Jichechang ground fissure in Datong, China, based on in-situ observations

Ruichun Liu,Qingliang Wang,Lingyun Ji,Chengsheng Yang

doi:10.1007/s12665-021-09715-2

Abstract

The Datong region of China suffers from severe ground fissure (GF) disasters. The Jichechang ground fissure (JGF) is typical among the GFs in Datong and is the most active. To provide scientific guidance for disaster mitigation, understanding the mechanisms governing GF activity in Datong needs to be improved. Here, long-term monitoring data (> 10 years) for the JGF are used to study the characteristics of its activity. The results show that the formation of GFs is mainly controlled by concealed faults. The JGF is mainly active in the vertical direction, with a differential vertical displacement 2.5 times greater than the horizontal displacement. The GF activity is periodic, with a periodicity of 320–420 days, which corresponds to the cycle of local agricultural irrigation. The JGF is especially active in June and July. The vertical activity of this fissure also displays a distinct quasi-periodic step-like displacement acceleration with a duration of 18–38 days. Numerical simulations show that irrigation pumping within 10 km of the JGF has a significant effect on the vertical movement of GFs. These results provide a better understanding of the mechanisms governing GF activity in this area and provide a valuable reference for the study of GFs in other regions.

Highlights

A ground fissure (GF) refers to the phenomenon in which the continuity of the rock or soil layer is destroyed, usually appearing as a crack on the ground surface (Wang et al 2000; Ye et al 2018)
The relative vertical displacement of the Jichechang ground fissure (JGF) is strongest during the spring and summer seasons and weakest in the autumn and winter
GF activity is highly seasonal, and periodic agricultural irrigation is considered the driving factor; the activity of the JGF is significantly enhanced during the agricultural irrigation season, and rainfall has less impact on seasonal activity

Summary

Introduction

A ground fissure (GF) refers to the phenomenon in which the continuity of the rock or soil layer is destroyed, usually appearing as a crack on the ground surface (Wang et al 2000; Ye et al 2018). Relative vertical and horizontal displacement data for the JGF were obtained for the period between 1998 and 2011 (Fig. 4).

Results

Conclusion