The new process-based hydrological toolbox model, RoGeR (https://roger.readthedocs.io/), can be used to estimate the components of the hydrological cycle and the related travel times of pollutants through parts of the hydrological cycle. These estimations may contribute to effective water resources management. This paper presents the toolbox concept and provides a simple example of providing estimations to water resources management.

We present a method to collect water vapor samples into bags in the field without an in-field analyser, followed by isotope analysis in the lab. This new method resolves even fine-scaled natural isotope variations. It combines low-cost and lightweight components for maximum spatial and temporal flexibility regarding environmental setups. Hence, it allows for sampling even in terrains that are rather difficult to access, enabling future extended isotope datasets in soil sciences and ecohydrology.

This study proposes a low-budget method to quantify the radial distribution of water transport velocities within trees at a high spatial resolution. We observed a wide spread of water transport velocities within a tree stem section, which were on average 3 times faster than the flux velocity. The distribution of transport velocities has implications for studies that use water isotopic signatures to study root water uptake and usually assume uniform or even implicitly infinite velocities.

Spatially explicit quantification of design storms is essential for flood risk assessment and planning. However, available datasets are mainly based on spatially interpolated station-based design storms. Since the spatial interpolation of the data inherits a large potential for uncertainty, we develop an approach to be able to derive spatially explicit design storms on the basis of weather radar data. We find that our approach leads to an improved spatial representation of design storms.

Analyzing the impact of soil age and rainfall intensity on vertical subsurface flow paths in calcareous soils, with a special focus on preferential flow occurrence, shows how water flow paths are linked to the organization of evolving landscapes. The observed increase in preferential flow occurrence with increasing moraine age provides important but rare data for a proper representation of hydrological processes within the feedback cycle of the hydro-pedo-geomorphological system.

This study is analyses how characteristics of precipitation events and soil moisture and temperature dynamics during these events can be used to model the associated streamflow responses in intermittent streams. The models are used to identify differences between the dominant controls of streamflow intermittency in three distinct geologies of the Attert catchment, Luxembourg. Overall, soil moisture was found to be the most important control of intermittent streamflow in all geologies.

We scrutinized the quickest currently available method for stable isotope analysis of matrix-bound water. Simulating common procedures, we demonstrated the limits of certain materials currently used and identified a reliable and cost-efficient alternative. Further, we calculated the optimum proportions of important protocol aspects critical for precise and accurate analyses. Our unifying protocol suggestions increase data quality and comparability as well as the method's general applicability.

We analyzed variability in diel nitrate patterns at three locations in a lowland stream. Comparison of time lags between monitoring sites with water travel time indicated that diel patterns were created by in-stream processes rather than transported downstream from an upstream point of origin. Most of the patterns (70 %) could be explained by assimilatory nitrate uptake. The remaining patterns suggest seasonally varying dominance and synchronicity of different biochemical processes.

We developed a setup for fully automated in situ measurements of stable water isotopes in soil and the stems of fully grown trees. We used this setup in a 12-week field campaign to monitor the propagation of a labelling pulse from the soil up to a stem height of 8 m. We could observe trees shifting their main water uptake depths multiple times, depending on water availability. The gained knowledge about the temporal dynamics can help to improve water uptake models and future study designs.

Spatially explicit quantification on design storms are essential for flood risk assessment. However this information can be only achieved from substantially long records of rainfall measurements, usually only available for a few stations. Hence, design storms estimates from these few stations are then spatially interpolated leading to a major source of uncertainty. Therefore we defined a methodology to extend spatially explicit weather radar data to be used for the estimation of design storms.

Our field observation-based examination of flow path evolution, soil formation and vegetation succession across ten millennia on calcareous parent material shows how water flow paths and subsurface water storage are linked to the organization of evolving landscapes. We provide important but rare data and observations for a proper handling of hydrologic processes and their role within the feedback cycle of the hydro-pedo-geomorphological system.

This paper presents FluSM, an algorithm to derive the water balance from soil moisture and metrological measurements. This data-driven water balance framework uses soil moisture as an input and therefore is applicable for cases with unclear processes and lacking parameters. In a case study, we apply FluSM to derive the water balance of 15 different permeable pavements under field conditions. These findings are of special interest for urban hydrology.

A better understanding of the reasons why model performance is unsatisfying represents a crucial part for meaningful model evaluation. We propose the novel diagnostic efficiency (DE) measure and diagnostic polar plots. The proposed evaluation approach provides a diagnostic tool for model developers and model users and facilitates interpretation of model performance.

We quantified the lateral and vertical subsurface flow (SSF) and P concentrations of three beech forest plots with contrasting soil properties during sprinkling experiments. Vertical SSF was 2 orders of magnitude larger than lateral SSF, and both consisted mainly of pre-event water. P concentrations in SSF were high during the first 1 to 2 h (nutrient flushing) but nearly constant thereafter. This suggests that P in the soil solution was replenished fast by mineral or organic sources.

Based on a unique and comprehensive data set of urban micro-meteorological variables, which were observed with a mobile climate station, we developed a new method to transfer mesoscale reference potential evapotranspiration to the urban microscale in street canyons. Our findings can be transferred easily to existing urban hydrologic models to improve modelling results with a more precise estimate of potential evapotranspiration on street level.

Our analysis of soil physical and hydraulic properties across two soil chronosequences of 10 millennia in the Swiss Alps provides important observation of the evolution of soil hydraulic behavior. A strong co-evolution of soil physical and hydraulic properties was revealed by the observed change of fast-draining coarse-textured soils to slow-draining soils with a high water-holding capacity in correlation with a distinct change in structural properties and organic matter content.

We investigated the interactions between streams and their adjacent hillslopes in terms of water flow. It could be revealed that soil structure has a strong influence on how hillslopes connect to the streams, while the groundwater table tells us a lot about when the two connect. This observation could be used to improve models that try to predict whether or not hillslopes are in a state where a rain event will be likely to produce a flood in the stream.

The data set CH-IRP provides isotope composition in precipitation and streamflow from 23 Swiss catchments, being unique regarding its long-term multi-catchment coverage along an alpine–pre-alpine gradient. CH-IRP contains fortnightly time series of stable water isotopes from streamflow grab samples complemented by time series in precipitation. Sampling conditions, catchment and climate information, lab standards and errors are provided together with areal precipitation and catchment boundaries.

In recent decades the demand for detailed information of spatial and temporal dynamics of the stream network has grown in the fields of eco-hydrology and extreme flow prediction. We use temporal streamflow intermittency data obtained at various sites using innovative sensing technology as well as spatial predictors to predict and map probabilities of streamflow intermittency. This approach has the potential to provide intermittency maps for hydrological modelling and management practices.