Long-term and high-frequency non-destructive monitoring of water stable isotope profiles in an evaporating soil column
Summary: Profiles of soil water stable isotopes were followed non-destructively and with high precision for a period of 290 days in the laboratory Rewatering at the end of the experiment led to instantaneous resetting of the isotope profiles, which could be closely followed with the new method The evaporation depth dynamics was determined from isotope gradients calculation Uncertainty associated with the determination of isotope kinetic fractionation where highlighted from inverse modeling.
Hydrol. Earth Syst. Sci., 19, 4067-4080, doi:10.5194/hess-19-4067-2015, 2015
The effect of empirical-statistical correction of intensity-dependent model errors on the temperature climate change signal
Summary: The effect of empirical-statistical bias correction methods, like quantile mapping (QM), on the simulated climate change signals (CCS) is currently strongly discussed and is often regarded as deficiency of bias correction methods. We demonstrate that, quite the contrary, QM can lead to an improved CCS and also has the potential to serve as an empirical constraint on model uncertainty in climate projections.
Hydrol. Earth Syst. Sci., 19, 4055-4066, doi:10.5194/hess-19-4055-2015, 2015
A methodological approach of estimating resistance to flow under unsteady flow conditions
Summary: This paper presents evaluation of resistance parameters: friction slope, friction velocity and Manning coefficient in unsteady flow. Theoretical description is facilitated with the analysis of field data from artificial dam-break flood waves in a small lowland watercourse. The methodology to enhance the evaluation of resistance by relations derived from flow equations is proposed. The study shows the Manning coefficient is less sensitive to simplified relations than other parameters.
Hydrol. Earth Syst. Sci., 19, 4041-4053, doi:10.5194/hess-19-4041-2015, 2015
High-resolution modelling of interactions between soil moisture and convective development in a mountain enclosed Tibetan Basin
Summary: Surface moisture is an important control for the development of clouds and precipitation on the Tibetan Plateau. While dry surface conditions do not provided enough water for the development of precipitation and convection, wet surface conditions lead to increased cloud cover and a decrease in solar irradiation, which also reduces convection development. It was found that intermediate soil moistures are associated with the strongest convection.
Hydrol. Earth Syst. Sci., 19, 4023-4040, doi:10.5194/hess-19-4023-2015, 2015
Singularity-sensitive gauge-based radar rainfall adjustment methods for urban hydrological applications
Summary: A new methodology is proposed in this paper, focusing on improving the applicability of the operational weather radar data to urban hydrology with rain gauge data. The proposed methodology employed a simple yet effective technique to extract additional information (called local singularity structure) from radar data, which was generally ignored in related works. The associated improvement can be particularly seen in capturing storm peak magnitudes, which is critical for urban applications.
Hydrol. Earth Syst. Sci., 19, 4001-4021, doi:10.5194/hess-19-4001-2015, 2015
Technical Note: The use of an interrupted-flow centrifugation method to characterise preferential flow in low permeability media
Summary: We present an interrupted-flow centrifugation technique to characterise the vertical hydraulic properties of dual porosity, low permeability media. Use of large core samples (100mm diameter) enables hydraulic-conductivity-scale issues in dual porosity media to be overcome. Elevated centrifugal force also enables simulating in situ total stress conditions. The methodology is an important tool to assess the ability of dual porosity aquitards to protect underlying aquifer systems.
Hydrol. Earth Syst. Sci., 19, 3991-4000, doi:10.5194/hess-19-3991-2015, 2015
Performance and robustness of probabilistic river forecasts computed with quantile regression based on multiple independent variables
Summary: This paper further develops the method of quantile regression (QR) to generate probabilistic river stage forecasts. Besides the forecast itself, this study uses the rate of rise of the river stage in the last 24 and 48h and the forecast error 24 and 48h before as predictors in QR configurations. When compared to just using the forecast as an independent variable, adding the latter four predictors significantly improved the forecasts, as measured by the Brier skill score and the CRPS.
Hydrol. Earth Syst. Sci., 19, 3969-3990, doi:10.5194/hess-19-3969-2015, 2015
Uncertainty in hydrological signatures
Summary: This study investigated the effect of uncertainties in data and calculation methods on hydrological signatures. We present a widely applicable method to evaluate signature uncertainty and show results for two example catchments. The uncertainties were often large (i.e. typical intervals of ±10–40% relative uncertainty) and highly variable between signatures. It is therefore important to consider uncertainty when signatures are used for hydrological and ecohydrological analyses and modelling.
Hydrol. Earth Syst. Sci., 19, 3951-3968, doi:10.5194/hess-19-3951-2015, 2015
Groundwater flow processes and mixing in active volcanic systems: the case of Guadalajara (Mexico)
Summary: A conceptual model of groundwater flow processes and mixing was developed using a combination of hydrogeochemistry, isotopes and multivariate analysis. The implementation to the case of Guadalajara showed that groundwater was classified into four groups: cold groundwater, hydrothermal water, polluted groundwater and mixed groundwater. A multivariate mixing model was used to calculate the proportion of different fluids in sampled well water. The result helps authorities in decision making.
Hydrol. Earth Syst. Sci., 19, 3937-3950, doi:10.5194/hess-19-3937-2015, 2015
Definition of efficient scarcity-based water pricing policies through stochastic programming
Summary: One of the most promising alternatives to improve the efficiency in water usage is the implementation of scarcity-based pricing policies based on the opportunity cost of water at the basin scale. Time series of the marginal value of water at selected locations (reservoirs) are obtained using a stochastic hydro-economic model and then post-processed to define step water pricing policies.
Hydrol. Earth Syst. Sci., 19, 3925-3935, doi:10.5194/hess-19-3925-2015, 2015
Flood triggering in Switzerland: the role of daily to monthly preceding precipitation
Summary: We investigate precipitation characteristics prior to 4000 annual floods in Switzerland since 1961. The floods were preceded by heavy precipitation, but in most catchments extreme precipitation occurred only during the last 3 days prior to the flood events. Precipitation sums for earlier time periods (like e.g. 4-14 days prior to floods) were mostly average and do not correlate with the return period of the floods.
Hydrol. Earth Syst. Sci., 19, 3903-3924, doi:10.5194/hess-19-3903-2015, 2015
Climate model uncertainty versus conceptual geological uncertainty in hydrological modeling
Summary: The impacts of climate model uncertainty and geological model uncertainty on hydraulic head, stream flow, travel time and capture zones are evaluated. Six versions of a physically based and distributed hydrological model, each containing a unique interpretation of the geological structure of the model area, are forced by 11 climate model projections. Geology is the dominating uncertainty source for travel time and capture zones, while climate dominates for hydraulic heads and steam flow.
Hydrol. Earth Syst. Sci., 19, 3891-3901, doi:10.5194/hess-19-3891-2015, 2015
Performance evaluation of groundwater model hydrostratigraphy from airborne electromagnetic data and lithological borehole logs
Hydrol. Earth Syst. Sci., 19, 3875-3890, doi:10.5194/hess-19-3875-2015, 2015
Computation of vertically averaged velocities in irregular sections of straight channels
Summary: We present two new methods for uniform flow computation, named LHRM and INCM. We also present the calibration and first validation from laboratory experimental data, second validation by field discharge hydrographs estimated by measured water level data, and the third validation from a 3-D solution of CFX code applied to a reach of the Alzette River.
Hydrol. Earth Syst. Sci., 19, 3857-3873, doi:10.5194/hess-19-3857-2015, 2015
Use of satellite and modeled soil moisture data for predicting event soil loss at plot scale
Summary: We developed a new formulation of USLE, named Soil Moisture for Erosion (SM4E), that directly incorporates soil moisture information. SM4E is applied here by using modeled data and satellite observations obtained from the Advanced SCATterometer (ASCAT). SM4E is found to outperform USLE and USLE-MM models in silty–clay soil in central Italy. Through satellite data, there is the potential of applying SM4E for large-scale monitoring and quantification of the soil erosion process.
Hydrol. Earth Syst. Sci., 19, 3845-3856, doi:10.5194/hess-19-3845-2015, 2015
GlobWat – a global water balance model to assess water use in irrigated agriculture
Summary: GlobWat is a freely distributed, global soil water balance model that is used by FAO to assess water use in irrigated agriculture, the main factor behind scarcity of freshwater in an increasing number of regions. The model is based on spatially distributed high-resolution data sets that are consistent at global level and is calibrated and validated against information published in global databases. The paper describes methodology, input and output data, calibration and validation of the model.
Hydrol. Earth Syst. Sci., 19, 3829-3844, doi:10.5194/hess-19-3829-2015, 2015
Influence of solar forcing, climate variability and modes of low-frequency atmospheric variability on summer floods in Switzerland
Summary: The paper presents an index of summer flood damage in Switzerland from 1800 to 2009 and explores the influence of solar forcing, climate variability and low-frequency atmospheric circulation on flood frequencies. The flood damage index provides evidence that the 1817-1851, 1881-1927, 1977-1990 and 2005-present flood clusters are mostly in phase with palaeoclimate proxies and solar activity minima. Floods are influenced by atmospheric instability related to the principal summer mode.
Hydrol. Earth Syst. Sci., 19, 3807-3827, doi:10.5194/hess-19-3807-2015, 2015
Quantifying energy and water fluxes in dry dune ecosystems of the Netherlands
Summary: This study explores the magnitude of energy and water fluxes in an inland dune ecosystem in the Netherlands. We parameterized the Penman-Monteith evapotranspiration model for four different surfaces: bare sand, moss, grass and heather. The knowledge presented in this paper will help improve the simulations of water recharge in sand dunes by hydrological models, and allow the quantification of the cost and benefit of nature conservation in terms of groundwater recharge.
Hydrol. Earth Syst. Sci., 19, 3787-3805, doi:10.5194/hess-19-3787-2015, 2015
Transit times from rainfall to baseflow in headwater catchments estimated using tritium: the Ovens River, Australia
Summary: This study documents the age of water that contributes to rivers in upper catchments using the radioactive tracer tritium. River water in the upper Ovens Valley (Australia) is several years to decades old and water from different parts of the catchment (e.g., soil, regolith, and groundwater) is mobilised at different flow conditions. The results indicate that these rivers are buffered against short term climate variability but are susceptible to longer-term climate and land use changes
Hydrol. Earth Syst. Sci., 19, 3771-3785, doi:10.5194/hess-19-3771-2015, 2015
A review of applications of satellite SAR, optical, altimetry and DEM data for surface water modelling, mapping and parameter estimation
Summary: Hydrological data collection is a challenge for the scientific community, especially as some events e.g. floods occur in un-gauged rivers or infrequently. Some such events are however recorded by satellites. Using satellite remote sensing in estimating surface water parameters has its limitations, but recent improvements in sensor specifications, expansion in research methods and knowledge of satellite data have increased its utilization. The review is on modelling and mapping with RS.
Hydrol. Earth Syst. Sci., 19, 3755-3769, doi:10.5194/hess-19-3755-2015, 2015