This study aims to understand how different reference periods (i.e., calibration periods) of climate data for estimating the drought index influence regional drought assessments. Specifically, we investigate the influence of different reference periods on historical drought characteristics such as trends, frequency, intensity and spatial extents using the Standard Precipitation Evapotranspiration Index (SPEI) estimated from the two widely used global datasets.

A field-scale average of near-surface water content can be sensed by cosmic-ray neutron detectors. To interpret, calibrate, and validate the integral signal, it is important to account for its sensitivity to heterogeneous patterns like dry or wet spots. We show how point samples contribute to the neutron signal based on their depth and distance from the detector. This approach robustly improves the sensor performance and data consistency, and even reveals otherwise hidden hydrological features.

This study uses a newly designed lysimeter to study three consecutive years (2013–2015) of deep soil recharge (DSR) underneath bare sand land on the eastern margin of Mu Us Sandy Land in the Ordos Basin of China. The objective is to identify the characteristics of the DSR distribution and the factors affecting the DSR distribution. Specifically, we would like to examine if the commonly used recharge coefficient concept can be applied for arid and semi-arid regions.

We characterized groundwater–lake exchange patterns and identified their controls based on extensive field measurements. Our measurement design bridges the gap between the detailed local characterisation and low resolution regional investigations. Results indicated strong spatial variability in groundwater inflow rates: large scale inflow patterns correlated with topography and the groundwater flow field and small scale patterns correlated with grainsize distributions of the lake sediment.

Humans have profoundly altered land cover and soil drainage for agricultural purposes in the Midwestern USA. Here we investigate whether climate alone can explain recent increases in observed streamflows throughout the region. Using multiple analyses, including statistical tests and water budgets, we conclude that historical drainage installation has likely amplified the streamflow response to regional precipitation increases. We stress that better documentation of artificial drainage is needed.

We used the Spatially Distributed Tracer-Aided Rainfall-Runoff model (STARR) to simulate streamflows, stable water isotope ratios, snowpack dynamics, and water ages in three snow-influenced experimental catchments with exceptionally long and rich datasets. Our simulations reproduced the hydrological observations in all three catchments, suggested contrasting stream water age distributions between catchments, and demonstrated the importance of snow isotope processes in tracer-aided modelling.

In Chile there is a lack of hydrological data, which complicates the analysis of important hydrological processes. In this study we validate a remote sensing product, i.e. the MODIS snow product, in Chile using ground observations, obtaining good results. Then MODIS was use to evaluated snow cover dynamic during 2000–2016 at five watersheds in Chile. The analysis shows that there is a significant reduction in snow cover area in two watersheds located in the northern part of the study area.

Providing large-scale (regional or global) simulation of floods at fine spatial resolution is difficult due to computational constraints but is necessary to provide consistent estimates of hazards, especially in data-scarce regions. We assessed the capability of an advanced global-scale river model to simulate an extreme flood at fine resolution. We found that when multiple flow connections in rivers are represented, the model can provide reliable fine-resolution predictions of flood inundation.

Spatiotemporal rainfall patterns in arid environments are not well-known. We derived properties of convective rain cells over the arid Dead Sea region from a long-term radar archive. We found differences in cell properties between synoptic systems and between flash-flood and non-flash-flood events. Large flash floods are associated with slow rain cells, directed downstream with the main catchment axis. Results from this work can be used for hydrological models and stochastic storm simulations.

In our study, we used a spatially and temporally high resolved 3-D ERT in addition to matric potential measurements to monitor the infiltration and subsurface water flow on a hillslope with layered slope deposits. We derived some interesting findings about the capillary barrier effect as a main driving factor for the activation of different flow pathways. Thus, the maintenance or breakdown of a capillary barrier has a decisive influence on the precipitation runoff response of of the catchment.

The new SMOS satellite near-real-time (NRT) soil moisture (SM) product based on a neural network is presented. The NRT SM product has been evaluated with respect to the SMOS Level 2 product and against a large number of in situ measurements showing performances similar to those of the Level 2 product but it is available in less than 3.5 h after sensing. The new product is distributed by the European Space Agency and the European Organisation for the Exploitation of Meteorological Satellites.

The Dinder and Rahad experienced significant hydrological changes in recent years. Some claim that this is due to land use & land cover change (LULCC). Specific studies on LULCC in the Dinder and Rahad basins are still missing. This paper aims to understand the LULCC in the Dinder and Rahad and its implications on streamflow using satellite data and hydrological modelling. We expect that this study will be of high importance for decision making related to water resource planning and management.

This study presents concentration and carbon isotope data of two herbicides from a small agricultural catchment. Herbicide concentrations at the catchment outlet were highest after intense rainfall events. The isotope data indicated herbicide degradation within 2 months after application. The system was modelled with a conceptual mathematical model using the transport formulation by travel-time distributions, which allowed testing of various assumptions of pesticide transport and degradation.

This research provides an example of how groundwater pressures measured in deep observation wells can be used as a reliable estimate, and perhaps as a reference, for event-based precipitation. Changes in loading at the surface due to the weight of precipitation are transferred to the groundwater formation and can be measured in the observation well. Correlations in precipitation measurements made with the geolysimeter and the co-located sheltered precipitation gauge are high.

Accurate flood and low-streamflow forecasting are important. The paper presents a methodology to evaluate ensemble streamflow-forecasting systems for different lead times; low, medium and high streamflow; and related runoff-generating processes. We applied the methodology to a study forecasting system of the Biała Tarnowska River in Poland. The results provide valuable information about the forecasting system: in which conditions it can be used and how the system can be improved effectively.

We introduce a data set describing the landscape of 671 catchments in the contiguous USA: we synthesized various data sources to characterize the topography, climate, streamflow, land cover, soil, and geology of each catchment. This extends the daily time series of meteorological forcing and discharge provided by an earlier study. The diversity of these catchments will help to improve our understanding and modeling of how the interplay between catchment attributes shapes hydrological processes.

Consistency in stage–discharge data is investigated using a methodology called Bidirectional Reach (BReach). Various measurement stations in the UK, New Zealand and Belgium are selected based on their historical ratings information and their characteristics related to data consistency. When applying a BReach analysis on them, the methodology provides results that appear consistent with the available knowledge and thus facilitates a reliable assessment of (in)consistency in stage–discharge data.

The Huangpu River, an important river of the basin connecting Lake Taihu upstream and the Yangtze River estuary downstream, drains two-fifths of the entire basin. Constructing an estuary gate is considered an effective solution for flood mitigation. The main objective of this paper is to assess the potential contributions of the proposed Huangpu Gate to the flood control capacity of the basin. Results of quantitative analyses show that the Huangpu Gate is effective at evacuating floodwaters.

In this study electromagnetic induction (EMI) measurements were used to estimate soil salinity in an agriculture field irrigated with a drip irrigation system. Electromagnetic model parameters and uncertainty were estimated using adaptive Bayesian Markov chain Monte Carlo (MCMC). Application of the MCMC-based inversion to the synthetic and field measurements demonstrates that the parameters of the model can be well estimated for the saline soil as compared to the non-saline soil.

Knowing the characteristics of extreme precipitation is useful for flood management applications like sewer system design. The potential of a 12-year high-quality weather radar precipitation dataset is investigated by comparison with rain gauges. Despite known limitations, a good agreement is found between the radar and the rain gauges. Using the radar data allow us to reduce the uncertainty of the extreme value analysis, especially for short duration extremes related to thunderstorms.