On the spatio-temporal dynamics of soil moisture at the field scale

- Characterizing soil moisture variability is key to understand soil water fluxes at the field scale.
- Novel measurement technologies provide unique possibilities to characterize soil moisture.
- Network monitoring design requires should better involve soil cover studies.
- Progress is needed in measurement quality at the extremes of the soil moisture range.
- Modeling is key to identify local and non-local on soil water dynamics.

SummaryIn this paper, we review the state of the art of characterizing and analyzing spatio-temporal dynamics of soil moisture content at the field scale. We discuss measurement techniques that have become available in recent years and that provide unique opportunities to characterize field scale soil moisture variability with high spatial and/or temporal resolution. These include soil moisture sensor networks, hydrogeophysical measurement techniques, novel remote sensing platforms, and cosmic ray probes. Techniques and methods to analyze soil moisture fields are briefly discussed and include temporal stability analysis, wavelet analysis and empirical orthogonal functions. We revisit local and non-local controls on field scale soil moisture dynamics and discuss approaches to model these dynamics at the field scale. Finally, we address the topic of optimal measurement design and provide an outlook and future research perspectives.