Exploring the feasibility of using the soil temperature to identify preferential and lateral subsurface flows

Soil temperature can be influenced by rapidly infiltrating water. Deviations from a uniform soil heat distribution could result vertical preferential flow (VPF) and lateral subsurface (LSF) events. The objective was to identify the effect of infiltration on time series in lysimeter with forced movement that sloping field distinguish between VPF LSF. Wavelet coherence analysis (WCA) used analyze measured Colluvic Regosol close surface (15-cm depth) below (80-cm horizon possible LSF occurrence. temperatures these depths were correlated at daily scale reflecting diurnal fluctuations air temperatures. A correlation monthly similar periodicity wavelet spectrum precipitation May through October 2015. In this period, 80-cm depth changed faster than field, indicating dominating infiltration-induced lysimeter. When assuming temperature-dampening laterally moving temperature-equilibrated water, observed deviations profiles indicative for field. However, occurrence only verified water content measurements single rainfall events May. useful qualitatively relevant series. For quantitative analysis, moisture data need considered.