Global catchment modelling using World-Wide HYPE (WWH), open data, andstepwise parameter estimation Hydrology and Earth System Sciences DOI 10.5194/hess-24-535-2020 11 February 2020 How far can we reach in predicting river flow globally, using integrated catchment modelling and open global data? For the first time, a catchment model was applied world-wide, covering the entire globe with a relatively high resolution. The results show that stepwise calibration provided better performance than traditional modelling of the globe. The study highlights that open data and models are crucial to advance hydrological sciences by sharing knowledge and enabling transparent evaluation. Read more
Seasonal partitioning of precipitation between streamflow and evapotranspiration, inferred from end-member splitting analysis Hydrology and Earth System Sciences DOI 10.5194/hess-24-17-2020 17 January 2020 Perhaps the oldest question in hydrology is “Where does water go when it rains?”. Here we present a new way to measure how the terrestrial water cycle partitions precipitation into its two ultimate fates: “green water” that is evaporated or transpired back to the atmosphere and “blue water” that is discharged to stream channels. Our analysis may help in gauging the vulnerability of both water resources and terrestrial ecosystems to changes in rainfall patterns. Read more
Distinct stores and the routing of water in the deep critical zone of a snow-dominated volcanic catchment Hydrology and Earth System Sciences DOI 10.5194/hess-23-4661-2019 3 December 2019 This paper examines the influence of the subsurface structure on water routing, water residence times, and the hydrologic response of distinct groundwater stores and further investigates their contribution to streamflow. We conclude that deep groundwater from the fractured aquifer system, rather than shallow groundwater, is the dominant source of streamflow, which highlights the need to better characterize the deep subsurface of mountain systems using interdisciplinary studies such as this one. Read more
Benchmarking the predictive capability of hydrological models for river flow and flood peak predictions across over 1000 catchments in Great Britain Hydrology and Earth System Sciences DOI 10.5194/hess-23-4011-2019 30 September 2019 We evaluated four hydrological model structures and their parameters on over 1100 catchments across Great Britain, considering modelling uncertainties. Models performed well for most catchments but failed in parts of Scotland and south-eastern England. Failures were often linked to inconsistencies in the water balance. This research shows what conceptual lumped models can achieve, gives insights into where and why these models may fail, and provides a benchmark of national modelling capability. Read more
Global-scale human pressure evolution imprints on sustainability of river systems Hydrology and Earth System Sciences DOI 10.5194/hess-23-3933-2019 25 September 2019 A simple and effective index for the quantitative estimation of the evolution of human pressure on rivers at global scale is proposed. This index, based on nightlights and river discharge data, shows a significant increase from 1992 to 2013 worldwide. The most notable changes are found in river basins across Africa and Asia, where human pressure on rivers is growing markedly. This index identifies priority areas that can be targeted for the implementation of mitigation strategies and plans. Read more
Summary and synthesis of Changing Cold Regions Network (CCRN) research in the interior of western Canada – Part 1: Projected climate and meteorology Hydrology and Earth System Sciences DOI 10.5194/hess-23-3437-2019 23 August 2019 This article examines future atmospheric-related phenomena across the interior of western Canada associated with abusiness-as-usualclimate scenario. Changes in large-scale atmospheric circulation and extent of warming vary with season, and these generally lead to increases, especially after mid-century, in factors associated with winter snowstorms, freezing rain, drought, forest fires, as well as atmospheric forcing of spring floods, although not necessarily summer convection. Read more
A salinity module for SWAT to simulate salt ion fate and transport at the watershed scale Hydrology and Earth System Sciences DOI 10.5194/hess-23-3155-2019 31 July 2019 Salinity is one of the most common water quality threats in river basins and irrigated regions worldwide. Available watershed models, however, do not simulate the fate and transport of salt species. This paper presents a modified version of the popular SWAT watershed model that simulates the transport of major salt ions in a watershed system. Salt is transported via surface runoff, soil percolation, groundwater flow, and streamflow. The model can be used in salt-affected watersheds worldwide. Read more
Assessing the characteristics and drivers of compound flooding events around the UK coast Hydrology and Earth System Sciences DOI 10.5194/hess-23-3117-2019 23 July 2019 Flooding can arise from multiple sources, including waves, extreme sea levels, rivers, and severe rainfall. When two or more sources combine, the consequences can be greatly multiplied. We find the potential for the joint occurrence of extreme sea levels and river discharge to be greater on the western coast of the UK compared to the eastern coast. This is due to the weather conditions generating each flood source around the UK. These results will help increase our flood forecasting ability. Read more
Technical note: A microcontroller-based automatic rain sampler for stable isotope studies Hydrology and Earth System Sciences DOI 10.5194/hess-23-2637-2019 19 June 2019 Most commercial automatic rain samplers are costly and do not prevent evaporation from the collection bottles. Hence, we have developed a microcontroller-based collector enabling timer-actuated integral rain sampling. The simple, low-cost device is robust and effectively minimizes post-sampling evaporation. The excellent performance of the collector during an evaporation experiment in a lab oven suggests that even multi-week field deployments in warm climates are feasible. Read more
Using a coupled agent-based modeling approach to analyze the role of risk perception in water management decisions Hydrology and Earth System Sciences DOI 10.5194/hess-23-2261-2019 10 May 2019 This study applies a two-way coupled agent-based model (ABM) with a river-reservoir management model (RiverWare) to analyze the role of risk perception in water management decisions using the Bayesian inference mapping joined with the cost–loss model. The calibration results capture the dynamics of historical irrigated area and streamflow changes and suggest that the proposed framework improves the representation of human decision-making processes compared to conventional rule-based ABMs. Read more
Controls on spatial and temporal variability in streamflow and hydrochemistry in a glacierized catchment Hydrology and Earth System Sciences DOI 10.5194/hess-23-2041-2019 24 April 2019 Hydrometric and geochemical dynamics are controlled by interplay of meteorological conditions, topography and geological heterogeneity. Nivo-meteorological indicators (such as global solar radiation, temperature and decreasing snow depth) explain monthly conductivity and isotopic dynamics best. These insights are important for better understanding hydrochemical responses of glacierized catchments under a changing cryosphere. Read more
Geostatistical interpolation by quantile kriging Hydrology and Earth System Sciences DOI 10.5194/hess-23-1633-2019 20 March 2019 Many variables, e.g., in hydrology, geology, and social sciences, are only observed at a few distinct measurement locations, and their actual distribution in the entire space remains unknown. We introduce the new geostatistical interpolation method ofquantile kriging, providing an improved estimator and associated uncertainty. It can also host variables, which would not fulfill the implicit presumptions of the traditional geostatistical interpolation methods. Read more
Attributing the 2017 Bangladesh floods from meteorological and hydrological perspectives Hydrology and Earth System Sciences DOI 10.5194/hess-23-1409-2019 13 March 2019 In August 2017 Bangladesh faced one of its worst river flooding events in recent history. For the large Brahmaputra basin, using precipitation alone as a proxy for flooding might not be appropriate. In this paper we explicitly test this assumption by performing an attribution of both precipitation and discharge as a flooding-related measure to climate change. We find the change in risk to be of similar order of magnitude (between 1 and 2) for both the meteorological and hydrological approach. Read more
Effects of univariate and multivariate bias correction on hydrological impact projections in alpine catchments Hydrology and Earth System Sciences DOI 10.5194/hess-23-1339-2019 11 March 2019 Several multivariate bias correction methods have been developed recently, but only a few studies have tested the effect of multivariate bias correction on hydrological impact projections. This study shows that incorporating or ignoring inter-variable relations between air temperature and precipitation can have a notable effect on the projected snowfall fraction. The effect translated to considerable consequences for the glacio-hydrological responses and streamflow components of the catchments. Read more
Conservative finite-volume forms of the Saint-Venant equations for hydrology and urban drainage Hydrology and Earth System Sciences DOI 10.5194/hess-23-1281-2019 7 March 2019 A new derivation of the equations for one-dimensional open-channel flow in rivers and storm drainage systems has been developed. The new approach solves some long-standing problems for obtaining well-behaved solutions with conservation forms of the equations. This research was motivated by the need for highly accurate models of large-scale river networks and the storm drainage systems in megacities. Such models are difficult to create with existing equation forms. Read more
Seasonal origins of soil water used by trees Hydrology and Earth System Sciences DOI 10.5194/hess-23-1199-2019 1 March 2019 We used stable isotopes of xylem water to study differences in the seasonal origin of water in more than 900 individual trees from three dominant species in 182 Swiss forested sites. We discovered that midsummer transpiration was mostly supplied by winter precipitation across diverse humid climates. Our findings provide new insights into tree vulnerability to droughts, transport of water (and thus solutes) in soils, and the climatic information conveyed by plant-tissue isotopes. Read more
A simple topography-driven and calibration-free runoff generation module Hydrology and Earth System Sciences DOI 10.5194/hess-23-787-2019 13 February 2019 Supported by large-sample ecological observations, a novel, simple and topography-driven runoff generation module (HSC-MCT) was created. The HSC-MCT is calibration-free, and therefore it can be used to predict in ungauged basins, and has great potential to be generalized at the global scale. Also, it allows us to reproduce the variation of saturation areas, which has great potential to be used for broader hydrological, ecological, climatological, and biogeochemical studies. Read more
Emergent stationarity in Yellow River sediment transport and the underlying shift of dominance: from streamflow to vegetation Hydrology and Earth System Sciences DOI 10.5194/hess-23-549-2019 30 January 2019 Our study shows that there is declining coupling between sediment concentration and discharge from daily to annual scales for gauges across the Yellow River basin (YRB). Not only the coupling, but also the magnitude of sediment response to discharge variation decreases with long-term mean discharge. This emergent stationarity can be related to sediment retardation by vegetation, suggesting the shift of dominance from water to vegetation as mean annual discharge increases. Read more
Quantifying new water fractions and transit time distributions using ensemble hydrograph separation: theory and benchmark tests Hydrology and Earth System Sciences DOI 10.5194/hess-23-303-2019 18 January 2019 How long does it take for raindrops to become streamflow? Here I propose a new approach to this old problem. I show how we can use time series of isotope data to measure the average fraction of same-day rainfall appearing in streamflow, even if this fraction varies greatly from rainstorm to rainstorm. I show that we can quantify how this fraction changes from small rainstorms to big ones, and from high flows to low flows, and how it changes with the lag time between rainfall and streamflow. Read more
Exploring the use of underground gravity monitoring to evaluate radar estimates of heavy rainfall Hydrology and Earth System Sciences DOI 10.5194/hess-23-93-2019 8 January 2019 In this study, we explore the use of an underground superconducting gravimeter as a new source of in situ observations for the evaluation of radar-based precipitation estimates. The comparison of radar and gravity time series over 15 years shows that short-duration intense rainfall events cause a rapid decrease in the measured gravity. Rainfall amounts can be derived from this decrease. The gravimeter allows capture of rainfall at a much larger spatial scale than a traditional rain gauge. Read more
Global phosphorus recovery from wastewater for agricultural reuse Hydrology and Earth System Sciences DOI 10.5194/hess-22-5781-2018 12 November 2018 Phosphorus (P) is important to global food security. Thus it is concerning that natural P reserves are predicted to deplete within the century. Here we explore the potential of P recovery from wastewater (WW) at global scale. We identify high production and demand sites to determine optimal market prices and trade flows. We show that 20% of the agricultural demand can be met, yet only 4 % can be met economically. Nonetheless, this recovery stimulates circular economic development in WW treatment. Read more
Modelling the water balance of Lake Victoria (East Africa) – Part 1: Observational analysis Hydrology and Earth System Sciences DOI 10.5194/hess-22-5509-2018 25 October 2018 Lake Victoria is the largest lake in Africa and one of the two major sources of the Nile river. The water level of Lake Victoria is determined by its water balance, consisting of lake precipitation and evaporation, inflow from rivers and lake outflow, controlled by two hydropower dams. Here, we present a water balance model for Lake Victoria, which closely represents the observed lake levels. The model results highlight the sensitivity of the lake level to human operations at the dam. Read more
Modelling the water balance of Lake Victoria (East Africa) – Part 2: Future projections Hydrology and Earth System Sciences DOI 10.5194/hess-22-5527-2018 25 October 2018 Lake Victoria is the second largest freshwater lake in the world and one of the major sources of the Nile River, which is controlled by two hydropower dams. In this paper we estimate the potential consequences of climate change for future water level fluctuations of Lake Victoria. Our results reveal that the operating strategies at the dam are the main controlling factors of future lake levels and that regional climate simulations used in the projections encompass large uncertainties. Read more
The importance of small artificial water bodies as sources of methane emissions in Queensland, Australia Hydrology and Earth System Sciences DOI 10.5194/hess-22-5281-2018 15 October 2018 Artificial water bodies are a major source of methane and an important contributor to flooded land greenhouse gas emissions. Past studies focussed on large water supply or hydropower reservoirs with small artificial water bodies (ponds) almost completely ignored. This regional study demonstrated ponds accounted for one-third of flooded land surface area and emitted over 1.6 million t CO2eq. yr−1(10 % of land use sector emissions). Ponds should be included in regional GHG inventories. Read more
Why has catchment evaporation increased in the past 40 years? A data-based study in Austria Hydrology and Earth System Sciences DOI 10.5194/hess-22-5143-2018 4 October 2018 We analyze changes in catchment evaporation estimated from the water balances of 156 catchments in Austria over 1977–2014, as well as the possible causes of these changes. Our results show that catchment evaporation increased on average by 29 ± 14 mm yr−1 decade−1. We attribute this increase to changes in atmospheric demand (based on reference and pan evaporation), changes in vegetation (quantified by a satellite-based vegetation index), and changes in precipitation. Read more
Global 5 km resolution estimates of secondary evaporation including irrigation through satellite data assimilation Hydrology and Earth System Sciences DOI 10.5194/hess-22-4959-2018 27 September 2018 Evaporation from wetlands, lakes and irrigation areas needs to be measured to understand water scarcity. So far, this has only been possible for small regions. Here, we develop a solution that can be applied at a very high resolution globally by making use of satellite observations. Our results show that 16% of global water resources evaporate before reaching the ocean, mostly from surface water. Irrigation water use is less than 1% globally but is a very large water user in several dry basins. Read more
Speculations on the application of foliar 13C discrimination to reveal groundwater dependency of vegetation and provide estimates of root depth and rates of groundwater use Hydrology and Earth System Sciences DOI 10.5194/hess-22-4875-2018 18 September 2018 Groundwater is a significant water resource for humans and for groundwater-dependent vegetation. Several challenges to managing both groundwater resources and dependent vegetation include defining the location of dependent vegetation, the rate of groundwater use, and the depth of roots accessing groundwater. In this study we demonstrate a novel application of measurements of stable isotopes of carbon that can be used to identify the location, the rooting depth, and the rate of groundwater use. Read more
Estimating time-dependent vegetation biases in the SMAP soil moisture product Hydrology and Earth System Sciences DOI 10.5194/hess-22-4473-2018 22 August 2018 Satellite soil moisture products can provide critical information on incipient droughts and the interplay between vegetation and water availability. However, time-variant systematic errors in the soil moisture products may impede their usefulness. Using a novel statistical approach, we detect such errors (associated with changing vegetation) in the SMAP soil moisture product. The vegetation-associated biases impede drought detection and the quantification of vegetation–water interactions. Read more
On the dynamic nature of hydrological similarity Hydrology and Earth System Sciences DOI 10.5194/hess-22-3663-2018 10 July 2018 In this study we explore the role of spatially distributed information on hydrological modeling. For that, we develop and test an approach which draws upon information theory and thermodynamic reasoning. We show that the proposed set of methods provide a powerful framework for understanding and diagnosing how and when process organization and functional similarity of hydrological systems emerge in time and, hence, when which landscape characteristic is important in a model application. Read more
Inter-laboratory comparison of cryogenic water extraction systems for stable isotope analysis of soil water Hydrology and Earth System Sciences DOI 10.5194/hess-22-3619-2018 6 July 2018 To extract water from soils for isotopic analysis, cryogenic water extraction is the most widely used removal technique. This work presents results from a worldwide laboratory intercomparison test of cryogenic extraction systems. Our results showed large differences in retrieved isotopic signatures among participating laboratories linked to interactions between soil type and properties, system setup, extraction efficiency, extraction system leaks, and each lab’s internal accuracy. Read more
HESS Opinions: Science in today’s media landscape – challenges and lessons from hydrologists and journalists Hydrology and Earth System Sciences DOI 10.5194/hess-22-3589-2018 4 July 2018 Media play a key role in the communication between scientists and the general public. However, the interaction between scientists and journalists is not always straightforward. In this opinion paper, we present insights from hydrologists and journalists into the benefits, aftermath and potential pitfalls of science–media interaction. We aim to encourage scientists to participate in the diverse and evolving media landscape, and we call on the scientific community to support scientists who do so. Read more
Effects of climatic seasonality on the isotopic composition of evaporating soil waters Hydrology and Earth System Sciences DOI 10.5194/hess-22-2881-2018 15 May 2018 Evaporation causes the isotopic composition of soil water to become different from that of the original precipitation source. If multiple samples originating from the same source are available, they can be used to reconstruct the original source composition. However, soil water is influenced by seasonal variability in both precipitation sources and evaporation patterns. We show that this variability, if not accounted for, can lead to biased estimates of the precipitation source water. Read more
A new method, with application, for analysis of the impacts on flood risk of widely distributed enhanced hillslope storage Hydrology and Earth System Sciences DOI 10.5194/hess-22-2589-2018 27 April 2018 Flooding is a significant hazard and extreme events in recent years have focused attention on effective means of reducing its risk. An approach known as natural flood management (NFM) seeks to increase flood resilience by a range of measures that work with natural processes. The paper develops a modelling approach to assess one type NFM of intervention – distributed additional hillslope storage features – and demonstrates that more strategic placement is required than has hitherto been applied. Read more
Regional evapotranspiration from an image-based implementation of the Surface Temperature Initiated Closure (STIC1.2) model and its validation across an aridity gradient in the conterminous US Hydrology and Earth System Sciences DOI 10.5194/hess-22-2311-2018 18 April 2018 We report the first ever regional-scale implementation of the Surface Temperature Initiated Closure (STIC1.2) model for mapping evapotranspiration (ET) using MODIS land surface and gridded climate datasets to overcome the existing uncertainties in aerodynamic temperature and conductance estimation in global ET models. Validation and intercomparison with SEBS and MOD16 products across an aridity gradient in the US manifested better ET mapping potential of STIC1.2 in different climates and biomes. Read more
Active heat pulse sensing of 3-D-flow fields in streambeds Hydrology and Earth System Sciences DOI 10.5194/hess-22-1917-2018 20 March 2018 This study used a portable 56-sensor, 3-D temperature array with three heat pulse sources to measure the flow direction and magnitude below the water–sediment interface. Breakthrough curves from each of the sensors were analyzed using a heat transport equation. The use of short-duration heat pulses provided a rapid, accurate assessment technique for determining dynamic and multi-directional flow patterns in the hyporheic zone and is a basis for improved understanding of biogeochemical processes. Read more
Decoupling of dissolved organic matter patterns between stream and riparian groundwater in a headwater forested catchment Hydrology and Earth System Sciences DOI 10.5194/hess-22-1897-2018 19 March 2018 Streams are important sources of carbon to the atmosphere, though knowing whether they merely outgas terrestrially derived carbon dioxide or mineralize terrestrial inputs of dissolved organic matter (DOM) is still a big challenge in ecology. Our study highlights that stream DOM is not merely a reflection of riparian groundwater entering the stream and that headwater streams have the capacity to internally produce, transform, and consume DOM. Read more
From engineering hydrology to Earth system science: milestones in the transformation of hydrologic science Hydrology and Earth System Sciences DOI 10.5194/hess-22-1665-2018 7 March 2018 The paper presents major milestones in the transformation of hydrologic science over the last 50 years from engineering hydrology to Earth system science. This transformation has involved a transition from a focus on time (empirical) to space (Newtonian mechanics), and to time (Darwinian co-evolution). Hydrology is now well positioned to again return to a focus on space or space–time and a move towards regional process hydrology. Read more
Using hydraulic head, chloride and electrical conductivity data to distinguish between mountain-front and mountain-block recharge to basin aquifers Hydrology and Earth System Sciences DOI 10.5194/hess-22-1629-2018 2 March 2018 This article tackles the problem of finding the origin of groundwater in basin aquifers adjacent to mountains. In particular, we aim to determine whether the recharge occurs predominantly through stream infiltration along the mountain front or through subsurface flow from the mountain. To this end, we discuss the use of routinely measured variables: hydraulic head, chloride and electrical conductivity. A case study from Australia demonstrates the approach. Read more
Imaging groundwater infiltration dynamics in the karst vadose zone with long-term ERT monitoring Hydrology and Earth System Sciences DOI 10.5194/hess-22-1563-2018 1 March 2018 Understanding water infiltration in karst regions is crucial as the aquifers they host provide drinkable water for a quarter of the world’s population. We present a non-invasive tool to image hydrological processes in karst systems. At our field site, the injection of electrical current in the ground, repeated daily over a 3-year period, allowed imaging changes in the groundwater content. We show that specific geological layers control seasonal to rainfall-triggered water infiltration dynamics. Read more
Citizen observations contributing to flood modelling: opportunities and challenges Hydrology and Earth System Sciences DOI 10.5194/hess-22-1473-2018 28 February 2018 Citizens can contribute to science by providing data, analysing them and as such contributing to decision-making processes. For example, citizens have collected water levels from gauges, which are important when simulating/forecasting floods, where data are usually scarce. This study reviewed such contributions and concluded that integration of citizen data may not be easy due to their spatio-temporal characteristics but that citizen data still proved valuable and can be used in flood modelling. Read more
Minimum forest cover required for sustainable water flow regulation of a watershed: a case study in Jambi Province, Indonesia Hydrology and Earth System Sciences DOI 10.5194/hess-22-581-2018 24 January 2018 This study is the first to describe the quantitative association between forest and plantation areas and the flow indicators (surface runoff and baseflow) in a watershed; this understanding is required by spatial planners if they are to balance the ecology and socioeconomic functions of a landscape with the rapid expansion of plantation crops. In addition, our study provides data regarding how SWAT input parameters related to tropical plantations such as oil palm and rubber should be adjusted. Read more
Can riparian vegetation shade mitigate the expected rise in stream temperatures due to climate change during heat waves in a human-impacted pre-alpine river? Hydrology and Earth System Sciences DOI 10.5194/hess-22-437-2018 18 January 2018 In eastern Austria, where air temperature rise is double that recorded globally, stream temperatures of a human-impacted river were simulated during heat waves, as calculated by regional climate models until 2100. An increase of up to 3 °C was predicted – thus exceeding thresholds of resident cold-adapted species. Vegetation management scenarios showed that adding vegetation can reduce both absolute temperatures and its rate of increase but is not able to fully mitigate the expected rise. Read more
The potamochemical symphony: new progress in the high-frequency acquisition of stream chemical data Hydrology and Earth System Sciences DOI 10.5194/hess-21-6153-2017 7 December 2017 We present a new prototypelab in the fieldnamed River Lab (RL) designed for water quality monitoring to perform a complete analysis at sub-hourly frequency of major dissolved species in river water. The article is an analytical paper to present the proof of concept, its performances and improvements. Our tests reveal a significant improvement of reproducibility compared to conventional analysis in the laboratory. First results are promising for understanding the critical zone. Read more
The CAMELS data set: catchment attributes and meteorology for large-sample studies Hydrology and Earth System Sciences DOI 10.5194/hess-21-5293-2017 20 October 2017 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. Read more
Improving calibration and validation of cosmic-ray neutron sensors in the light of spatial sensitivity Hydrology and Earth System Sciences DOI 10.5194/hess-21-5009-2017 6 October 2017 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. Read more
Complex relationship between seasonal streamflow forecast skill and value in reservoir operations Hydrology and Earth System Sciences DOI 10.5194/hess-21-4841-2017 28 September 2017 This study investigates the relationship between skill and value of ensemble seasonal streamflow forecasts. Using data from a modern forecasting system, we show that skilled forecasts are more likely to provide benefits for reservoirs operated to maintain a target water level rather than reservoirs operated to satisfy a target demand. We identify the primary causes for this behaviour and provide specific recommendations for assessing the value of forecasts for reservoirs with supply objectives. Read more
A national-scale seasonal hydrological forecast system: development and evaluation over Britain Hydrology and Earth System Sciences DOI 10.5194/hess-21-4681-2017 15 September 2017 The research presented here provides the first evaluation of the skill of a seasonal hydrological forecast for the UK. The forecast scheme combines rainfall forecasts from the Met Office GloSea5 forecast system with a national-scale hydrological model to provide estimates of river flows 1 to 3 months ahead. The skill in the combined model is assessed for different seasons and regions of Britain, and the analysis indicates that Autumn/Winter flows can be forecast with reasonable confidence. Read more
Has dyke development in the Vietnamese Mekong Delta shifted flood hazard downstream? Hydrology and Earth System Sciences DOI 10.5194/hess-21-3991-2017 7 August 2017 In this study we provide a numerical quantification of changes in flood hazard in the Vietnamese Mekong Delta as a result of dyke development. Other important drivers to the alteration of delta flood hazard are also investigated, e.g. tidal level. The findings of our study are substantial valuable for the decision makers in Vietnam to develop holistic and harmonized floods and flood-related issues management plan for the whole delta. Read more
An intercomparison of approaches for improving operational seasonal streamflow forecasts Hydrology and Earth System Sciences DOI 10.5194/hess-21-3915-2017 31 July 2017 Water supply forecasts are critical to support water resources operations and planning. The skill of such forecasts depends on our knowledge of (i) future meteorological conditions and (ii) the amount of water stored in a basin. We address this problem by testing several approaches that make use of these sources of predictability, either separately or in a combined fashion. The main goal is to understand the marginal benefits of both information and methodological complexity in forecast skill. Read more
Every apple has a voice: using stable isotopes to teach about food sourcing and the water cycle Hydrology and Earth System Sciences DOI 10.5194/hess-21-3799-2017 25 July 2017 Fruits take up soil water as they grow, and thus the fruit water is related to the rain or irrigation the crop receives. We used a novel sampling system to measure the stable isotopes of H and O in the fruit water to determine its geographic origin by comparing it to maps of isotopes in rain. We used this approach to teach an audience of science students and teachers about water cycle concepts and how humans may modify the water cycle through agriculture and irrigation water diversions. Read more