TY - JOUR

T1 - Revealing the temporal dynamics of subsurface temperature in a wetland using time-lapse geophysics

AU - Musgrave, Heather

AU - Binley, Andrew

PY - 2011/1/13

Y1 - 2011/1/13

N2 - There is growing recognition of the need to understand the subsurface hydrological mechanisms within wetlands, given their potentially significant role in the hydrological and biogeochemical function of catchments, as well as their effects on the wetland habitat itself. Conventional subsurface hydrological sampling and monitoring techniques are often limited in such environments because of the invasive nature of such approaches and the sensitivity of the environment. As with other areas of subsurface hydrology, there is widespread appreciation of the value of using geophysical surveys to compliment observations from direct sampling. In this study we use ground penetrating radar (GPR) and electrical resistivity tomography (ERT) to characterise the stratigraphy at a small riparian wetland site. Then, through time-lapse ERT measurements over a 12 month period, we demonstrate how changes in resistivity may provide additional value about localised recharge, through inferred changes in subsurface temperature. Although we focus here on one 2-D vertical profile through the wetland, the results highlight the potential value of non-invasive time-lapse geoelectrical surveys for mapping 3-D thermal patterns within a wetland environment.

AB - There is growing recognition of the need to understand the subsurface hydrological mechanisms within wetlands, given their potentially significant role in the hydrological and biogeochemical function of catchments, as well as their effects on the wetland habitat itself. Conventional subsurface hydrological sampling and monitoring techniques are often limited in such environments because of the invasive nature of such approaches and the sensitivity of the environment. As with other areas of subsurface hydrology, there is widespread appreciation of the value of using geophysical surveys to compliment observations from direct sampling. In this study we use ground penetrating radar (GPR) and electrical resistivity tomography (ERT) to characterise the stratigraphy at a small riparian wetland site. Then, through time-lapse ERT measurements over a 12 month period, we demonstrate how changes in resistivity may provide additional value about localised recharge, through inferred changes in subsurface temperature. Although we focus here on one 2-D vertical profile through the wetland, the results highlight the potential value of non-invasive time-lapse geoelectrical surveys for mapping 3-D thermal patterns within a wetland environment.

KW - Wetland

KW - Hydrogeophysics

KW - Temperature

KW - Resistivity

U2 - 10.1016/j.jhydrol.2010.11.008

DO - 10.1016/j.jhydrol.2010.11.008

M3 - Journal article

VL - 396

SP - 258

EP - 266

JO - Journal of Hydrology

JF - Journal of Hydrology

IS - 3-4

ER -