This study shows that streamflow isotope data in a catchment-scale isotope-based transport model were sufficient to isolate preferential flow in the unsaturated zone but insufficient to isolate the preferential release of young groundwater, as isotope signals were strongly damped by large passive groundwater storage. As a result, groundwater age-selection assumptions affected estimates of long transit times, making it difficult to quantify the fraction of stream water older than 100 days.

Understanding the role of soil in the storage of organic carbon is critical for a large number of environmental processes. Current practices rely on the drilling and analysis of samples, which is expensive, time consuming and destructive. Here we present a technique able to map soil organic carbon measuring the electrical properties of the subsurface without the necessity of drilling. Our results could permit to advance soil management strategies to enhance carbon sequestration and storage.

Using advances in transit time estimation and tracer data, we tested if fast-flow transit times are controlled solely by soil moisture or if they are also controlled by precipitation intensity. We used soil-moisture-dependent and precipitation-intensity-conditional transfer functions. We showed that a significant portion of event water bypasses the soil matrix through fast flow paths (overland flow, tile drains, preferential-flow paths) in dry soil conditions for both low- and high-intensity precipitation.

We studied how farming practices affect soil and sediment movement in a small Austrian catchment. By monitoring water and sediment during 55 rain events, we found that erosion control worked well in flat fields near the stream, but not in steep or distant fields. Our results show that reducing soil loss requires strategies that consider slope, distance to streams, and how water flows through the landscape.

This study explored the quantitative contribution of agricultural intensification and climate change to the sediment load of a small agricultural watershed. Rather than a change in climatic conditions, changes in the land structure notably altered sediment concentrations under high-flow conditions, thereby contributing most to the increase in annual sediment loads. More consideration of land structure improvement is required when combating the transfer of soil from land to water.