EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

A physical model demonstrating critical zone structure and flow processes in headwaters

Xuhui Shen1,2, Jintao Liu1,2, Wanjie Wang2, Xiaole Han1,3, Jie Zhang2, and Guofang Li2
Xuhui Shen et al.
  • 1State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China
  • 2College of Hydrology and Water Resources, Hohai University, Nanjing, China
  • 3School of Earth Sciences and Engineering, Hohai University, Nanjing, China

Equipped with complex terrain structure, physical models provide an alternative way in understanding and modeling how critical zone shapes hydrologic processes in headwaters for research and education in hydrology. However, this type of physical models is limited by frustrating rain-erosion or gully-erosion. Herein, in order to replace the real-world backfilling soil, we drew on the experience of normal concrete workmanship and adjusted the raw material’s proportion for three times. And it is found that saturated hydraulic conductivity (SHC) and field moisture capacity (FMC) are both well correlated with bulk density (BD) for the developed materials in three cases. Thereby, based on the strongest correlation (R2=0.75) between SHC and BD, two-layer alternative soil has been designed through altering BD in the physical model with complex terrain. The SHC values of alternative soil are close to that of the natural soil while the FMC values are far lower. Additionally, the non-uniform scaling of bedrock terrain was applied for the convenience of teaching and construction by zooming out a steep 0.31-ha zero-order basin 130 times horizontally and 30 times vertically. And multiple observation items, including free water level, temperature and humidity of soil, as well as outflow could provide potential opportunity to explore the role of single or combined critical zone’s element in modulating streamflow. We’d like to share this effective tool to facilitate the development of critical zone science and enrich experimental teaching methods.

How to cite: Shen, X., Liu, J., Wang, W., Han, X., Zhang, J., and Li, G.: A physical model demonstrating critical zone structure and flow processes in headwaters, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5400,, 2021.