Determining air permeability in reclaimed coastal land based on tidal fluctuations |
| |
Authors: | Jian Li Hongbin Zhan Guanhua Huang and Kehua You |
| |
Institution: | (1) Department of Irrigation and Drainage, College of Water Conservancy and Civil Engineering, China Agricultural University, Beijing, 100083, People’s Republic of China;(2) Chinese Academy of Agricultural Engineering, Ministry of Agriculture, Beijing, 100125, People’s Republic of China;(3) Chinese-Israeli International Center for Research and Training in Agriculture, China Agricultural University, Beijing, 100083, People’s Republic of China;(4) Department of Geology and Geophysics, Texas A&M University, College Station, TX 77843-3115, USA |
| |
Abstract: | Coastal land reclamation is a common practice in many regions around the World. A reclaimed coastal land often has a two-layer
system: a highly permeable layer consisting of crushed rock fragments underneath a less permeable layer. This study deals
with vertical airflow in a reclaimed coastal land induced by the periodic variations of water table elevation due to tide
fluctuations. The influence of atmospheric pressure fluctuations can be easily dealt with through a simple superposition procedure
reported by Li and Jiao, thus is not considered here. A time-series Fourier analysis method is developed to determine air
permeability based on a tide-induced airflow model reported by Li and Jiao for the reclaimed coastal land. This method employs
the amplitude attenuations of subsurface air pressure to search for values of dimensionless air-leaking-resistance which can
be subsequently used to calculate air permeability. Two types of data, the air pressure data in the upper less permeable layer
and the tidal fluctuation data, are required to calculate the air permeability. Type curves relating to the amplitude attenuations
and the relative depth can also be used to determine the values of air permeability. A field site in Hong Kong International
Airport is used to demonstrate the applicability of this method for reclaimed coastal land consisting of a marine sand layer
above a layer of crushed rock fragments. The application shows that the amplitude attenuations of diurnal and semi-diurnal
components in the Fourier series are most reliable for determining the value of air permeability. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|