Urbanization dramatically altered the water balances of a paddy field-dominated basin in southern China
Summary: The role of land cover in affecting hydrologic and environmental changes in the humid region in southern China is not well studied. We found that high flows and low flows increased and evapotranspiration decreased due to urbanization in the Qinhuai River basin. Urbanization masked climate warming effects in a rice-paddy-dominated watershed in altering long-term hydrology. Flooding risks and heat island effects are expected to rise due to urbanization.
Hydrol. Earth Syst. Sci., 19, 3319-3331, doi:10.5194/hess-19-3319-2015, 2015
Complex network theory, streamflow, and hydrometric monitoring system design
Hydrol. Earth Syst. Sci., 19, 3301-3318, doi:10.5194/hess-19-3301-2015, 2015
Estimation of crop water requirements: extending the one-step approach to dual crop coefficients
Hydrol. Earth Syst. Sci., 19, 3287-3299, doi:10.5194/hess-19-3287-2015, 2015
Early warning of drought in Europe using the monthly ensemble system from ECMWF
Summary: This paper assesses the predictability of meteorological droughts over Europe 1 month in advance using ensemble prediction systems. It has been shown that, on average and using the most relevant method, 40 % of droughts in Europe are correctly forecasted, with less than 25 % false alarms. This study is a reference for other studies that are motivated to improving the drought forecasting.
Hydrol. Earth Syst. Sci., 19, 3273-3286, doi:10.5194/hess-19-3273-2015, 2015
GRACE storage-runoff hystereses reveal the dynamics of regional watersheds
Summary: The paper demonstrates how data from the Gravity Recovery and Climate Experiment (GRACE) can be used to describe the relationship between water stored at the regional scale and stream flow. Additionally, we employ GRACE as a regional-scale indicator to successfully predict stream flow later in the water year. Our work focuses on the Columbia River Basin (North America), but is widely applicable across the globe, and could prove to be particularly useful in regions with limited hydrological data.
Hydrol. Earth Syst. Sci., 19, 3253-3272, doi:10.5194/hess-19-3253-2015, 2015
Flood and drought hydrologic monitoring: the role of model parameter uncertainty
Summary: Land surface modeling is playing an increasing role in global monitoring and prediction of extreme hydrologic events. However, uncertainties in parameter identifiability limit the reliability of model predictions. This study makes use of petascale computing to perform a comprehensive evaluation of land surface modeling for global flood and drought monitoring and suggests paths forward to overcome the challenges posed by parameter uncertainty.
Hydrol. Earth Syst. Sci., 19, 3239-3251, doi:10.5194/hess-19-3239-2015, 2015
Impacts of climate change on temperature, precipitation and hydrology in Finland – studies using bias corrected Regional Climate Model data
Summary: With most scenarios the DBS method used preserves the temperature and precipitation trends of the uncorrected RCM data and produces more realistic projections for mean annual and seasonal changes in discharges than the uncorrected RCM data in Finland. However, if the biases in the mean or the standard deviation of the uncorrected temperatures are large, significant biases after DBS adjustment may remain or temperature trends may change, increasing the uncertainty of climate change projections.
Hydrol. Earth Syst. Sci., 19, 3217-3238, doi:10.5194/hess-19-3217-2015, 2015
Investigating temporal field sampling strategies for site-specific calibration of three soil moisture–neutron intensity parameterisation methods
Summary: The cosmic-ray neutron sensor can provide soil moisture content averages over areas of roughly half a kilometre by half a kilometre. Although this sensor is usually calibrated using soil samples taken on a single day, we found that multiple sampling days are needed. The calibration results were also affected by the soil wetness conditions of the sampling days. The outcome of this study will help researchers to calibrate/validate new cosmic-ray neutron sensor sites more accurately.
Hydrol. Earth Syst. Sci., 19, 3203-3216, doi:10.5194/hess-19-3203-2015, 2015
Estimation of predictive hydrologic uncertainty using the quantile regression and UNEEC methods and their comparison on contrasting catchments
Hydrol. Earth Syst. Sci., 19, 3181-3201, doi:10.5194/hess-19-3181-2015, 2015
Exploring the impact of forcing error characteristics on physically based snow simulations within a global sensitivity analysis framework
Summary: A sensitivity analysis is used to examine how error characteristics (type, distributions, and magnitudes) in meteorological forcing data impact outputs from a physics-based snow model in four climates. Bias and error magnitudes were key factors in model sensitivity and precipitation bias often dominated. However, the relative importance of forcings depended somewhat on the selected model output. Forcing uncertainty was comparable to model structural uncertainty as found in other studies.
Hydrol. Earth Syst. Sci., 19, 3153-3179, doi:10.5194/hess-19-3153-2015, 2015
Hydrological connectivity inferred from diatom transport through the riparian-stream system
Summary: We tested the hypothesis that different diatom species assemblages inhabit specific moisture domains of the catchment and, consequently, the presence of certain species assemblages in the stream during runoff events offers the potential for recording whether there was hydrological connectivity between these domains or not. In the Weierbach catchment, the transport of aerial diatoms during events suggested a rapid connectivity between the soil surface and the stream.
Hydrol. Earth Syst. Sci., 19, 3133-3151, doi:10.5194/hess-19-3133-2015, 2015
Evaluation of land surface model simulations of evapotranspiration over a 12-year crop succession: impact of soil hydraulic and vegetation properties
Summary: Land surface model simulations of evapotranspiration are assessed over a 12-year Mediterranean crop succession. Evapotranspiration mainly results from soil evaporation when it is simulated over a Mediterranean crop succession. This leads to a high sensitivity to the soil parameters. Errors on soil hydraulic properties can lead to a large bias in cumulative evapotranspiration over a long period of time. Accounting for uncertainties in soil properties is essential for land surface modelling.
Hydrol. Earth Syst. Sci., 19, 3109-3131, doi:10.5194/hess-19-3109-2015, 2015
Attribution of European precipitation and temperature trends to changes in synoptic circulation
Hydrol. Earth Syst. Sci., 19, 3093-3107, doi:10.5194/hess-19-3093-2015, 2015
Water savings potentials of irrigation systems: global simulation of processes and linkages
Summary: We present a process-based simulation of global irrigation systems for the world’s major crop types. This study advances the global quantification of irrigation systems while providing a framework for assessing potential future transitions in these systems, a prerequisite for refined simulation of crop yields under climate change. We reveal for many river basins the potential for sizeable water savings and related increases in water productivity through irrigation improvements.
Hydrol. Earth Syst. Sci., 19, 3073-3091, doi:10.5194/hess-19-3073-2015, 2015
A 2600-year history of floods in the Bernese Alps, Switzerland: frequencies, mechanisms and climate forcing
Summary: A 2600-year long composite palaeoflood record is reconstructed from high-resolution delta plain sediments of the Hasli-Aare floodplain on the northern slope of the Swiss Alps. Natural proxies compiled from sedimentary, geochemical and geomorphological data were calibrated by textual and factual sources and instrumental data. Geomorphological, historical and instrumental data provide evidence for flood damage intensities and discharge estimations of severe and catastrophic historical floods.
Hydrol. Earth Syst. Sci., 19, 3047-3072, doi:10.5194/hess-19-3047-2015, 2015
Time series analysis of the long-term hydrologic impacts of afforestation in the Águeda watershed of north-central Portugal
Hydrol. Earth Syst. Sci., 19, 3033-3045, doi:10.5194/hess-19-3033-2015, 2015
Vulnerability of groundwater resources to interaction with river water in a boreal catchment
Summary: Based on low-altitude aerial infrared surveys, around 370 groundwater–surface water interaction sites were located. Longitudinal temperature patterns, stable isotopes and dissolved silica composition of the studied rivers differed. Interaction sites identified in the proximity of 12 municipal water plants during low-flow seasons should be considered as potential risk areas during flood periods and should be taken under consideration in river basin management under changing climatic situations.
Hydrol. Earth Syst. Sci., 19, 3015-3032, doi:10.5194/hess-19-3015-2015, 2015
Data assimilation in integrated hydrological modeling using ensemble Kalman filtering: evaluating the effect of ensemble size and localization on filter performance
Hydrol. Earth Syst. Sci., 19, 2999-3013, doi:10.5194/hess-19-2999-2015, 2015
Propagation of hydro-meteorological uncertainty in a model cascade framework to inundation prediction
Summary: The study is an investigation on the propagation of hydro-meteorological uncertainty within a model cascade applied to flood prediction. Uncertainty is evaluated at meteorological and hydrological levels in a hindcast scenario, which allows for its generation from the rainfall prediction to its interaction at a catchment level, and propagation to an estimated inundation area and depth. A complex aggregation of errors is demonstrated with larger effect on inundation depths than flood extents.
Hydrol. Earth Syst. Sci., 19, 2981-2998, doi:10.5194/hess-19-2981-2015, 2015
Analyses of uncertainties and scaling of groundwater level fluctuations
Summary: The error or uncertainty in head, obtained with an analytical or numerical solution, at an early time is mainly caused by the random initial condition. The error reduces with time, later reaching a constant error. The constant error at a later time is mainly due to the effects of the uncertain source/sink. The error caused by the uncertain boundary is limited to a narrow zone. Temporal scaling of head exists in most parts of a low permeable aquifer, mainly caused by recharge fluctuation.
Hydrol. Earth Syst. Sci., 19, 2971-2979, doi:10.5194/hess-19-2971-2015, 2015