Geophysical measurements to track soil water and biochemical dynamics

Abstract:

Of the main limitations characterizing most subsurface hydrological measurements are the invasiveness, destructiveness and their discontinuous nature. To significant extent, geophysical measurements overcome these limitations and provide a continuous measurement of physical properties of the subsurface, which can be related to hydrological properties and system state. In this poster, we will demonstrate several applications of geophysical measurements at various scales to study both water and solute dynamics in the subsurface.

First, we will demonstrate how calibration of a flow and transport model using resistivity data can help separate water and solute dynamics, a crucial aspect in arid and semi-arid regions where soil-water conductivity cannot be assumed constant in neither space nor time. This allows tracking water and salt dynamics in drip-irrigated orchard, and better estimation of the recharge generation under such orchards. Next, we will demonstrate the value of raw resistivity measurements to understand the dynamics of a soil aquifer treatment (SAT) facility. We will show how a sophisticated system behavior may be captured by one or two quadruple measurement once the system is calibrated. Last, we will show how induced polarization data can be used to study chemical state and dynamics in the soil, including various ion exchange processes. We see the combination of these tools as the right venue to monitor subsurface dynamics at all scales in a non-invasive way.