Canada is very susceptible to recurrent droughts, which have damaging impacts on regional water resources and agriculture. However, nationwide drought assessments are currently lacking and impacted by limited ground-based observations. We delineate two major drought regions (Prairies and northern central) over Canada and link drought characteristics to external factors of climate variability. This study helps to determine when the drought events occur, their duration, and how often they occur.

Climate change is one of the most pressing challenges modern society faces. Increasing temperatures are observed both above ground and, as discussed here, in the groundwater – the source of most drinking water. Within Austria average temperature increased by 0.7 °C over the past 20 years, with an increase of more than 3 °C in some wells and temperature decrease in others. However, these extreme changes can be linked to local events such as the construction of a new drinking water supply.

This study examines hydroclimate variability in northeastern Argentina; advances the understanding of its links with global SST forcing; and discusses its impacts on water resources, agriculture and human settlements. Interannual-to-multidecadal variability led to frequent extreme events. Severe floods affected agriculture, livestock productivity, and forced population displacements. Droughts affected water resources, causing water and food scarcity. Increased temperatures reduced crop yields.

This study presents a multivariate bias correction method named R²D² to adjust both the 1d-distributions and inter-variable/site dependence structures of climate simulations in a high-dimensional context, while providing some stochasticity. R²D² is tested on temperature and precipitation reanalyses and illustrated on future simulations. In both cases, R²D² is able to correct the spatial and physical dependence, opening proper use of climate simulations for impact (e.g. hydrological) models.

Precipitating thunderstorms can occasionally be triggered by the propagation of a front associated with a circulation similar to a land–sea breeze but caused by the contrast of soil patches with different moisture contents. In this study, using an idealized framework, we quantify which fraction of surface rain comes from the contribution of the aforementioned front and which fraction comes from local evaporation. Results show that these two major sources contribute differently.

In this work, we have developed a methodology to evaluate the failure risk of managed aquifer recharge, and we have applied it to six different facilities located in the Mediterranean Basin. The methodology was based on the development of a probabilistic risk assessment based on fault trees. We evaluated both technical and non-technical issues, the latter being more responsible for failure risk.

This paper provides the first detailed and comprehensive study regarding the potential for reducing the grey WF of crop production by changing management practice such as the nitrogen application rate, nitrogen form (inorganic N or manure N), tillage practice and irrigation strategy. The paper shows that although water pollution (grey WF) can be reduced dramatically, this comes together with a great yield reduction.

Permanent gullies are deep steep-sided channels that erode as water falls over the upstream end. Erosion of these features is a concern where people and climate change have altered how water moves over the land. This paper analyzes a set of experiments that were used to determine how changing gully flows impact erosion. We found that while increasing the volume of water will increase erosion, changing the flow rate into gullies will not impact the total erosion, but will alter gully shape.

In North Africa rain storms can be as vital as they are devastating. The present study uses multi-year satellite data to better understand how and where soil moisture conditions affect development of rainfall in the area. Our results reveal two major regions in the southwest and southeast, where drier soils show higher potential to cause rainfall development. This knowledge is essential for the hydrological sector, and can be further used by models to improve prediction of rainfall and droughts.

Arctic and subarctic regions are amongst the most susceptible regions on Earth to climate change. There, models require a proper representation of the interactions between climate and hydrology. Typically these model represent the soil with shallow depths, whereas for cold regions, deep soil is needed. To address this, we run model experiments to characterize the effect of soil depth and temperature soil initialization. Our results demonstrate that 20 m of soil profile is essential.

The petabytes of existing global environmental data provide an invaluable asset to improve the characterization of land heterogeneity in Earth system models. This study introduces a clustering algorithm that summarizes a domain's heterogeneity through spatially interconnected clusters. A series of land model simulations in central California using this approach illustrate the critical role that multi-scale heterogeneity can have on the macroscale water, energy, and carbon cycles.

Temperature and precipitation can have abnormal states due to climate change and exert a significant impact on the regional hydrologic cycle. We assess the hydrologic component changes in the Alps and northern Italy, on the basis of regional future climate (FC) conditions, using the UTOPIA land surface model. The annual mean number of dry (wet) days increase remarkably (slightly) in FCs, thus increasing the risk of severe droughts and slightly increasing the risk of floods coincidently.

Three-dimensional geological models are important to securing and managing groundwater. Such models describe the geological architecture, which is used for modeling the flow of groundwater. Common geological modeling approaches result in one model, which does not quantify the architectural uncertainty of the geology. We present a comparison of three different state-of-the-art stochastic multiple-point statistical methods for quantifying the geological uncertainty using real-world datasets.

Many researchers have expressed that one of the main difficulties in modeling watershed hydrology is that of obtaining continuous, widespread weather input data, especially precipitation. The overarching objective of this study was to provide a comprehensive study of three weather radars as a function of range. We found that radar-estimated precipitation was best at ranges between 100 and 150 km from the radar, with different radar parameters being superior at varying distances from the radar.

The effects of WRF domain configurations and spin-up time on rainfall were evaluated at high temporal and spatial scales for simulating an extreme sub-daily heavy rainfall (SDHR) event. Both objective verification metrics and subjective verification were used to identify the likely best set of the configurations. Results show that re-evaluation of these WRF settings is of great importance in improving the accuracy and reliability of the rainfall simulations in the regional SDHR applications.

This study aims to bridge the gap between water resources forecasts from the short-range (days) up to the long-range (seasonal) timescale. Applications of such a system are typically the waterpower industry, river and lake transports, and water resources management. The study uses a new meteorological forecast product combined with a hydrological model to predict river discharge over the major European river basins. The results show an improvement in comparison with the current system.

We analyse the control of hydroclimatic factors – erosive rainfall, ice melt, and snowmelt – on suspended sediment concentration (SSC) of Alpine catchments regulated by hydropower, and we develop a multivariate hydroclimatic–informed rating curve. We show that while erosive rainfall determines the variability of SSC, ice melt generates the highest contribution to SSC per unit of runoff. This approach allows the exploration of climate–driven changes in fine sediment dynamics in Alpine catchments.

Understanding the precipitation characteristics is essential to design an optimal observation network. We studied the spatial and temporal characteristics of summertime precipitation systems in Korea via geostatistical analyses on the ground-based precipitation and satellite water vapor data. We found that, under a strict standard, an observation network with higher resolution is required in local areas with frequent heavy rainfalls, depending on directional features of precipitation systems.

This paper presents the development and skill analysis of WUSHP, a system that makes hydrological forecasts for time horizons up to 7 months. Hot spots of significant skill in river discharge were identified in Fennoscandia (from January to October), the southern part of the Mediterranean (from June to August), Poland, north Germany, Romania and Bulgaria (mainly from November to January), and west France (from December to May). Some skill is left at the end of the forecasts.

Based on hydrochemical and isotopic analysis, we investigated the potential hydrogeological processes responsible for the increasing groundwater salinity in the coastal aquifer of Yang–Dai River coastal plain, northern China. Seawater intrusion is the major aspect and can be caused by vertical infiltration along the riverbed at the downstream areas, and lateral inflow into fresh aquifer. Geothermal water also makes a significant contribution to increasing the groundwater salinity.

Debris flows represent a severe hazard in mountain regions and so far remain difficult to predict. We applied a hydrological model to link not only precipitation, but also snowmelt, antecedent soil moisture, etc. with debris flow initiation in an Alpine watershed in Austria. Our results highlight the value of this more holistic perspective for developing a better understanding of debris flow initiation.

ECMWF recently released the first 7-year segment of its latest atmospheric reanalysis: ERA-5 (2010–2016). ERA-5 has important changes relative to ERA-Interim including higher spatial and temporal resolutions as well as a more recent model and data assimilation system. ERA-5 is foreseen to replace ERA-Interim reanalysis. One of the main goals of this study is to assess whether ERA-5 can enhance the simulation performances with respect to ERA-Interim when it is used to force a land surface model.

Predictions of irrigation-season water availability are important for water-limited Pakistan. We assess a Bayesian joint probability approach, using flow and climate indices as predictors, to produce streamflow forecasts for inflow to Pakistan's two largest dams. The approach produces skilful and reliable forecasts. As it is simple and quick to apply, it can be used to provide probabilistic seasonal streamflow forecasts that can inform Pakistan's water management.

A relationship between the Hurst (H) exponent (a long-term correlation coefficient) within a flow time series and various catchment characteristics for a number of catchments in the USA and Australia was investigated. A negative relationship with imperviousness was identified, which allowed for an efficient catchment classification, thus making the H exponent a useful metric to quantitatively assess the impact of catchment imperviousness on streamflow regime.