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The spatial patterns of groundwater recharge on hillslopes with a thin soil mantle overlying bedrock are poorly known. Complex interactions between vertical percolation of water through the soil, permeability contrasts between soil and bedrock and lateral redistribution of water result in large spatial variability of water moving into the bedrock. Here, we combine new measurements of saturated hydraulic conductivity of soil mantle and bedrock of the well‐studied Panola Mountain experimental hillslope with previously collected (sub)surface topography and soil depth data to quantify the factors affecting the spatial pattern of bedrock groundwater recharge. We use geostatistical characteristics of the measured permeability to generate spatial fields of saturated hydraulic conductivity for the entire hillslope. We perform simulations with a new conceptual model with these random fields and evaluate the resulting spatial distribution of groundwater recharge during individual rainstorms and series of rainfall events. Our simulations show that unsaturated drainage from soil into bedrock is the prevailing recharge mechanism and accounts for 60% of annual groundwater recharge. Therefore, soil depth is a major control on the groundwater recharge pattern through available storage capacity and controlling the size of vertical flux. The other 40% of recharge occurs during storms that feature transient saturation at the soil‐bedrock interface. Under these conditions, locations that can sustain increased subsurface saturation because of their topographical characteristics or those with high bedrock permeability will act as hotspots of groundwater recharge when they receive lateral flow. Copyright © 2015 John Wiley & Sons, Ltd.

Microtopography can have a large eff ect on fl ow processes at the soil surface and the composi on of soil water. Microtopography is o en represented by a roughness parameter in hydrological models. In areas without a strong topographical gradient, microtopography may be underes mated when accumulated in a single parameter, especially in shallow groundwater systems. This study reviews the intricate rela onships between microtopography, surface runoff , and ecohydrology in systems featuring shallow water tables. We specifi cally focus on rela ons between microtopography and runoff , impact of microtopography on response mes of shallow groundwater ecosystems, and microtopography and spa al distribu on of groundwater quality parameters and site factors. We advocate the use of microtopography in modeling approaches by examples that feature typical ecosystems with shallow groundwater under infl uence of microtopography. With a simple modeling approach, we show how microtopography could add fl exibility to the acrotelmcatotelm concept in raised bog hydrology. The classic acrotelm-catotelm concept hinders progress in understanding small scale hydrological varia ons and other ecohydrological rela ons. Furthermore, we illustrate possible self-organiza on proper es of wetlands. Finally, we show how microtopography and surface runoff aff ect the mixing of water with diff erent chemical signatures, resul ng in varia ons of the occurrence of plant species.

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