Author(s): Abdoul Rachid Ouedraogo; Shaohua Hsu

Linked Author(s): Abdoul Rachid Ouédraogo

Keywords: Over-pumping; Linear Signal Model (LSM); Pumping Recovery Strength (PRS); Groundwater reference level (hb); Chou-Shui Chi alluvial fan

Abstract: Over-pumping of groundwater to satisfy the water demand for agriculture, industrial, and domestics uses in the central region of Taiwan has caused considerable drop of groundwater level and a large-scale land subsidence. However, the demand for groundwater resources is still increasing, and it is impossible, currently in Taiwan, to completely ban all pumping. There has been an urgent need to understand the groundwater situation in central Taiwan for several decades. In order to identify the over-pumping area in Chou-Shui Chi alluvial fan, this research proposes establishing a Linear Signal Model (LSM) for groundwater by using the hourly records of groundwater fluctuation level and the rainfall events observed in the Chou-Shui Chi alluvial fan for the past decades. Then, the LSM is used to identify the main pumping characteristics from the groundwater observation data and also simulate the variation of the groundwater level. By using LSM, four parameters, which are the natural loss, the recharge coefficient, the artificial pumping coefficient and the groundwater reference level, will be generated with different physical meanings, and this study try to understand the indication of those parameter in this groundwater system. The achievement of this study proves that LSM can be used for groundwater prediction and describe aquifer characteristics. The most relevant is the groundwater reference level (hb), our results demonstrate that hb can be used as the groundwater reference level in order to avoid the over-pumping that may lead to land-subsidence.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022104

Year: 2022