A partially coupled hydro-mechanical analysis of the Bengal Aquifer System under hydrological loading
| Autor: | N. Woodman, Anwar Zahid, WG Burgess, Kazi Matin Ahmed |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
010504 meteorology & atmospheric sciences
0208 environmental biotechnology Aquifer 02 engineering and technology 01 natural sciences lcsh:Technology lcsh:TD1-1066 Hydraulic head Geotechnics lcsh:Environmental technology. Sanitary engineering lcsh:Environmental sciences 0105 earth and related environmental sciences Hydrology lcsh:GE1-350 geography geography.geographical_feature_category Hydrogeology lcsh:T Piezometer lcsh:Geography. Anthropology. Recreation Groundwater recharge 020801 environmental engineering lcsh:G Structural geology Geology Groundwater |
| Zdroj: | Hydrology and Earth System Sciences, Vol 23, Pp 2461-2479 (2019) |
| ISSN: | 1607-7938 1027-5606 |
| Popis: | The coupled poro-mechanical behaviour of geologic-fluid systems is fundamental to numerous processes in structural geology, seismology, and geotechnics, but is frequently overlooked in hydrogeology. Substantial poro-mechanical influences on groundwater head have recently been highlighted in the Bengal Aquifer System, however, driven by terrestrial water loading across the Ganges–Brahmaputra–Meghna floodplains. Groundwater management in this strategically important fluvio-deltaic aquifer, the largest in southern Asia, requires a coupled hydro-mechanical approach which acknowledges poroelasticity. We present a simple partially coupled, 1-D poroelastic model of the Bengal Aquifer System, and explore the poro-mechanical responses of the aquifer to surface boundary conditions representing hydraulic head and mechanical load under three modes of terrestrial water variation. The characteristic responses, shown as amplitude and phase of hydraulic head in depth profile and of ground surface deflection, demonstrate (i) the limits to using water levels in piezometers to indicate groundwater recharge, as conventionally applied in groundwater resources management; (ii) the conditions under which piezometer water levels respond primarily to changes in the mass of terrestrial water storage, as applied in geological weighing lysimetry; (iii) the relationship of ground surface vertical deflection with changes in groundwater storage; and (iv) errors of attribution that could result from ignoring the poroelastic behaviour of the aquifer. These concepts are illustrated through application of the partially coupled model to interpret multi-level piezometer data at two sites in southern Bangladesh. There is a need for further research into the coupled responses of the aquifer due to more complex forms of surface loading, particularly from rivers. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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