The water balance components of undisturbed tropical woodlands in the Brazilian Cerrado
Summary: We determined the main components of the water balance for an undisturbed dense cerrado.
Evapotranspiration (ET) ranged from 1.91 to 2.60 mm d-1 for the dry and wet season, respectively. Canopy interception ranged from 4 to 20% and stemflow values were approximately 1% of gross precipitation.
The average runoff coefficient was less than 1%, while Cerrado deforestation has the potential to increase that amount up to 20 fold.
The water storage may be estimated by the difference between P and ET.
P. T. S. Oliveira, E. Wendland, M. A. Nearing, R. L. Scott, R. Rosolem, and H. R. da Rocha Hydrol. Earth Syst. Sci. Discuss., 11, 12987-13018, 2014 AbstractDiscussion Paper (PDF, 2971 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
21 Nov 2014
Multi-annual droughts in the English Lowlands: a review of their characteristics and climate drivers in the winter half year
Summary: The English Lowlands is a heavily populated, water stressed region, which is vulnerable to long droughts typically associated with dry winters. We conduct a long-term (1910 - present) quantitative analysis of precipitation, flow and groundwater droughts for the region, and then review potential climatic drivers. No single driver is dominant but we demonstrate, for the first time, a physical link between La Nina conditions and winter rainfall, associated with long droughts in the region.
C. K. Folland, J. Hannaford, J. P. Bloomfield, M. Kendon, C. Svensson, B. P. Marchant, J. Prior, and E. Wallace Hydrol. Earth Syst. Sci. Discuss., 11, 12933-12985, 2014 AbstractDiscussion Paper (PDF, 8573 KB)Supplement (590 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
21 Nov 2014
Towards observation based gridded runoff estimates for Europe
Summary: Water storages and fluxes on land are key variables in the earth system. To provide context for local investigations and to understand phenomena that emerge at large spatial scales, information on continental freshwater dynamics is necessary. This paper presents a methodology to estimate continental scale runoff on a 0.5° spatial grid, which combines the advantages of in-situ observations with the power of machine learning regression. The resulting runoff estimates compare well with observations
Investigation of variable threshold level approaches for hydrological drought identification
Summary: This paper explores possible threshold level calculation methods for hydrological drought analysis. We proposed four threshold methods applied to time series of hydrometeorological variables and inter-compared the drought propagation patterns. Our results have shown that these methods can influence the magnitude and severity of droughts differently and even may introduce artefact drought events. Therefore, we suggest the use and checking of these threshold approaches for drought analysis.
B. S. Beyene, A. F. Van Loon, H. A. J. Van Lanen, and P. J. J. F. Torfs Hydrol. Earth Syst. Sci. Discuss., 11, 12765-12797, 2014 AbstractDiscussion Paper (PDF, 991 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
17 Nov 2014
Spatial extremes modeling applied to extreme precipitation data in the state of Paraná
R. A. Olinda, J. Blanchet, C. A. C. dos Santos, V. A. Ozaki, and P. J. Ribeiro Jr. Hydrol. Earth Syst. Sci. Discuss., 11, 12731-12764, 2014 AbstractDiscussion Paper (PDF, 5568 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
17 Nov 2014
Understanding NMR relaxometry of partially water-saturated rocks
Comparing bias correction methods in downscaling meteorological variables for hydrologic impact study in an arid area in China
Summary: 1. Select meteorological variables to be corrected through a sensitivity analysis based on Sobol' method
2. Compare effects of five precipitation and three temperature correction methods on precipitation, temperature, and streamflow
3. Loosely couple RCM (RegCM) and a distributed hydrological model (SWAT)
4. Methodology and results can be used for other regions and other RCM and hydrologic models, and for impact study of climate change on water resources at a regional scale.
Shallow groundwater thermal sensitivity to climate change and land cover disturbances: derivation of analytical expressions and implications for stream temperature projections
Summary: Changes in climate and land cover are known to warm streams by altering surface heat fluxes. However, the influence of these disturbances on shallow groundwater temperature are not as well understood. In small streams, groundwater discharge may also exert a control on stream temperature, and thus groundwater warming may eventually produce additional stream warming not considered in most existing models. This study investigates these processes and suggests stream temperature model improvements.
A snow cover climatology for the Pyrenees from MODIS snow products
S. Gascoin, O. Hagolle, M. Huc, L. Jarlan, J.-F. Dejoux, C. Szczypta, R. Marti, and R. Sánchez Hydrol. Earth Syst. Sci. Discuss., 11, 12531-12571, 2014 AbstractDiscussion Paper (PDF, 6169 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
12 Nov 2014
Technical Note: A simple generalization of the Brutsaert and Nieber analysis
Summary: We propose a simple modification of the Brutsaert-Nieber analysis of aquifers during a hydrologic recession that allows for the non-zero depth of the adjoining stream to the aquifer to be duly taken into account. This modification can produce significantly different values of the estimated drainable porosity, as found by a simple sensitivity analysis.
Natural stochasticity vs. management effort: use of year-to-year variance for disentangling significance of two mutually confounding factors affecting water quality of a Norwegian cold dimictic lake
Summary: We disentangled two major factors that affects lake water quality, namely the meteorological conditions and loading from the catchment.
In previous studies, distinction of these two major factors was not always sought.
However, from the management point of view quantifying these two factors may be of interest, for example because the managers may want to evaluate the effectiveness of abatement plan that reduced catchment loading despite the unfavourable meteorological conditions.
Sampling frequency trade-offs in the assessment of mean transit times of tropical montane catchment waters under semi-steady-state conditions
Summary: Stream, soil and precipitation waters were collected in a tropical montane cloud forest catchment for two years and analyzed for stable water isotopes in order to infer transit time distribution functions and mean transit times for semi-steady-state conditions. Samples were aggregated to diverse sampling resolutions for checking the sensitivity of sampling frequency on lumped-model predictions. Results provide valuable information for the planning of future fieldwork in similar catchments.
E. Timbe, D. Windhorst, R. Celleri, L. Timbe, P. Crespo, H.-G. Frede, J. Feyen, and L. Breuer Hydrol. Earth Syst. Sci. Discuss., 11, 12443-12488, 2014 AbstractDiscussion Paper (PDF, 6067 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
07 Nov 2014
Groundwater surface mapping informs sources of catchment baseflow
Summary: Groundwater surface mapping is used as an independent dataset to better estimates of groundwater discharge to streamflow. The groundwater surfaces indicated when other techniques overestimate groundwater discharge during periods of higher streamflow. Groundwater surfaces also identified areas where regional groundwater could not be contributing to tributary streamflow. This method adds significant value to water resource management where sufficient groundwater monitoring data are available.
Quantitative high-resolution observations of soil water dynamics in a complicated architecture with time-lapse Ground-Penetrating Radar
Summary: In this study, we analyze a set of high-resolution, surface-based, 2-D Ground-Penetrating Radar (GPR) observations of artificially induced subsurface water dynamics. In particular, we place close scrutiny on the evolution of the capillary fringe in a highly dynamic regime with surface based time-lapse GPR. We thoroughly explain all observed phenomena based on theoretical soil physical considerations and numerical simulations of both subsurface water flow and the expected GPR response.
Simulating long-term past changes in the balance between water demand and availability and assessing their main drivers at the river basin management scale
Summary: Socio-economic and hydro-climatic data were used to model water resources, water demand and their interactions in two river basins. By using an integrative framework we successfully modeled variations in water stress over the past 40 years, accounting for climate and human pressures and changes in water management strategies over time. We explained past changes in discharge by separating human and hydro-climatic trends. This work will help assess future water stress and design adaptation plans.
Technical Note: Field experiences using UV/VIS sensors for high-resolution monitoring of nitrate in groundwater
Summary: Two different in-situ spectrophotometers are compared that were used in the field to determine highly time resolved nitrate-nitrogen (NO3-N) concentrations at two distinct spring discharge sites: A double and a multiple wavelenght spectrophotometer.The objective of the study was to review the hardware options, determine ease of calibration, accuracy, influence of additional substances and to assess positive and negative aspects of the two sensors as well as troubleshooting and trade-offs.
M. Huebsch, F. Grimmeisen, M. Zemann, O. Fenton, K. G. Richards, P. Jordan, A. Sawarieh, P. Blum, and N. Goldscheider Hydrol. Earth Syst. Sci. Discuss., 11, 12291-12314, 2014 AbstractDiscussion Paper (PDF, 3092 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESSSpecial Issue
04 Nov 2014
Is sinuosity a function of slope and bankfull discharge? – A case study of the meandering rivers in the Pannonian Basin
Summary: We described how the sinuosity of the meandering rivers influenced by the channel-slope and the bankfull-discharge. We defined an approximated mathematical function (least squares regression), and analysed the existence of this connection in the Pannonian Basin. The differences believed to be the effect of the non-analysed changes in the sediment discharge.
Time-series analysis of the long-term hydrologic impacts of afforestation in the Águeda watershed of North-Central Portugal
D. Hawtree, J. P. Nunes, J. J. Keizer, R. Jacinto, J. Santos, M. E. Rial-Rivas, A.-K. Boulet, F. Tavares-Wahren, and K.-H. Feger Hydrol. Earth Syst. Sci. Discuss., 11, 12223-12256, 2014 AbstractDiscussion Paper (PDF, 2573 KB)Supplement (42 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for HESS
04 Nov 2014
Linking baseflow separation and groundwater storage dynamics in an alpine basin (Dammagletscher, Switzerland)
Improving inflow forecasting into hydropower reservoirs through a complementary modelling framework
Summary: We present a forecasting system comprising additively setup conceptual and simple error model. Parameters of the conceptual model were left unaltered, as are in most operational setups, and the data-driven model was arranged to forecast the corrective measures the conceptual model needs. We demonstrate that the present procedure could effectively improve forecast accuracy over extended lead-times and the probabilistic forecasts satisfy reliability requirements for lead-times up to 17 hours.
GRACE storage-streamflow 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.
E. A. Sproles, S. G. Leibowitz, J. T. Reager, P. J. Wigington Jr., J. S. Famiglietti, and S. D. Patil Hydrol. Earth Syst. Sci. Discuss., 11, 12027-12062, 2014 AbstractDiscussion Paper (PDF, 1852 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
30 Oct 2014
Spatial sensitivity analysis of snow cover data in a distributed rainfall–runoff model
Spatial and temporal variability of rainfall in the Nile Basin
Summary: Variability of rainfall in the Nile basin was found linked to the large scale atmosphere-ocean interactions. This finding is vital for a number of water management and planning aspects. To give just one example, it may help in obtaining improved quantiles for flood or drought/water scarcity risk management. This is especially important under conditions of: (1) questionable data quality, and (2) data scarcity. These conditions are typical of the Nile basin and inevitably need to be addressed.
Impacts of a changing climate on a century of extreme flood regime of northwest Australia
Summary: We reconstructed a 100 year monthly history of flooding and drought of a large wetland in arid northwest Australia, using hydroclimatic data calibrated against 25 years of satellite images. Severe and intense regional rainfall, as well as the sequence of events, determined surface water expression on the floodplain. While inter-annual variability was high, changes to the flood regime over the last 20 years suggest the wetland may become more persistent in response to the observed rainfall trend.
A. Rouillard, G. Skrzypek, S. Dogramaci, C. Turney, and P. F. Grierson Hydrol. Earth Syst. Sci. Discuss., 11, 11905-11943, 2014 AbstractDiscussion Paper (PDF, 1249 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
24 Oct 2014
Technical Note: Surface water velocity observations from a camera: a case study on the Tiber River
Data assimilation of GRACE terrestrial water storage estimates into a regional hydrological model of the Rhine River basin
N. Tangdamrongsub, S. C. Steele-Dunne, B. C. Gunter, P. G. Ditmar, and A. H. Weerts Hydrol. Earth Syst. Sci. Discuss., 11, 11837-11882, 2014 AbstractDiscussion Paper (PDF, 6470 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for HESS
24 Oct 2014
An extended modeling approach to assess climate change impacts on groundwater recharge and adaptation in arid areas
Using variograms to detect and attribute hydrological change
Summary: Current hydrological change detection methods are subject to a host of limitations. This paper develops a new method, Temporally Shifting Variograms (TSV), which characterises variability in the river flow regime using several parameters, changes in which can then be attributed to precipitation characteristics. We demonstrate the use of the method through application to 94 UK catchments, showing that periods of extremes as well as more subtle changes can be detected.
A. Chiverton, J. Hannaford, I. Holman, R. Corstanje, C. Prudhomme, T. M. Hess, and J. P. Bloomfield Hydrol. Earth Syst. Sci. Discuss., 11, 11763-11795, 2014 AbstractDiscussion Paper (PDF, 2747 KB)Interactive Discussion (Open, 3 Comments)Manuscript under review for HESS
23 Oct 2014
A dynamic water accounting framework based on marginal resource opportunity cost
Evaluation of land surface model simulations of evapotranspiration over a 12 year crop succession: impact of the soil hydraulic properties
Summary: - Evapotranspiration mainly results from soil evaporation when it is simulated over a Mediterranean crop succession. Accounting for crop succession in land surface models is essential for proper representation of surface-atmosphere interactions.
- Errors on soil hydraulic properties have great impact on multi-year simulation of evapotranspiration. Accounting for them is essential for the spatial integration of land surface models and their use in climatic change scenarios.
S. Garrigues, A. Olioso, J.-C. Calvet, E. Martin, S. Lafont, S. Moulin, A. Chanzy, O. Marloie, V. Desfonds, N. Bertrand, and D. Renard Hydrol. Earth Syst. Sci. Discuss., 11, 11687-11733, 2014 AbstractDiscussion Paper (PDF, 1875 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
23 Oct 2014
Extreme value statistics of scalable data exemplified by neutron porosities in deep boreholes
Summary: Previously we have shown that many earth system and other variables can be viewed as samples from scale-mixtures of truncated fractional Brownian motion or fractional Gaussian noise. Here we study statistical scaling of extreme absolute increments associated with such samples. As a real example we analyze neutron porosities from deep boreholes in diverse depositional units. Phenomena we uncover are relevant to the analysis of fluid flow and solute transport in complex hydrogeologic environments.
A. Guadagnini, S. P. Neuman, T. Nan, M. Riva, and C. L. Winter Hydrol. Earth Syst. Sci. Discuss., 11, 11637-11686, 2014 AbstractDiscussion Paper (PDF, 2972 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
22 Oct 2014
On the skill of high frequency precipitation analyses
Summary: The paper introduces a high resolution precipitation analysis system which operates on 1 km x 1 km resolution with high frequency updates of 5 minutes. The ability of such a system to adequately assess the convective precipitation distribution is evaluated by means of an independant, high resolution station network. This dense station network allows for a thorough evaluation of the analyses under different convective situations and of the representativeness error of raingaue measurements.
A. Kann, I. Meirold-Mautner, F. Schmid, G. Kirchengast, and J. Fuchsberger Hydrol. Earth Syst. Sci. Discuss., 11, 11605-11636, 2014 AbstractDiscussion Paper (PDF, 2119 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
21 Oct 2014
The question of Sudan: a hydroeconomic optimization model for the Sudanese Nile
Identifying water mass depletion in Northern Iraq observed by GRACE
Summary: During 2007 till 2009, Northern Iraq suffered a severe drought and satellite measurements indicate a water loss of about 31 km3 in the same period. To identify the main causes of this water loss we developed a model based on geology, remote sensing and stream flow data. Model results indicate that groundwater extraction has a minor influence on the water depletion in the region, while natural groundwater depletion plays a key role.
G. Mulder, T. N. Olsthoorn, D. A. M. A. Al-Manmi, E. J. O. Schrama, and E. H. Smidt Hydrol. Earth Syst. Sci. Discuss., 11, 11533-11563, 2014 AbstractDiscussion Paper (PDF, 5543 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for HESS
17 Oct 2014
Evaluation of precipitation estimates over CONUS derived from satellite, radar, and rain gauge datasets (2002–2012)
Global trends in extreme precipitation: climate models vs. observations
Summary: We present a systematic comparison of changes in historical extreme precipitation in station observations (HadEX2) and 15 climate models from the CMIP5 (as the largest and most recent sets of available observational and modeled datasets), in global and continental scale for 1901-2010, using both parametric (linear regression) and non-parametric (the Mann-Kendall as well as Sen’s slope estimator) methods, taking care to spatially and temporally sample observations and models in comparable ways.
Estimating flow and transport parameters in the unsaturated zone with pore water stable isotopes
Summary: The submitted paper presents a novel approach that inlcudes information about the pore waters isotopic composition in inverse model apporaches to estimate soil physical parameter. Different approaches are presented and their adequacy regarding the model efficiency, realism and parameter identifiability are discussed. The advantages of the new approach are shown by an application of the inverse estimated parameters to infer the water balance and the transit time for three different study site.
Operational river discharge forecasting in poorly gauged basins: the Kavango River Basin case study
P. Bauer-Gottwein, I. H. Jensen, R. Guzinski, G. K. T. Bredtoft, S. Hansen, and C. I. Michailovsky Hydrol. Earth Syst. Sci. Discuss., 11, 11071-11108, 2014 AbstractDiscussion Paper (PDF, 789 KB)Interactive Discussion (Open, 8 Comments)Manuscript under review for HESS
08 Oct 2014
Modeling suspended sediment sources and transport in the Ishikari River Basin, Japan using SPARROW
Improving operational flood ensemble prediction by the assimilation of satellite soil moisture: comparison between lumped and semi-distributed schemes
C. Alvarez-Garreton, D. Ryu, A. W. Western, C.-H. Su, W. T. Crow, D. E. Robertson, and C. Leahy Hydrol. Earth Syst. Sci. Discuss., 11, 10635-10681, 2014 AbstractDiscussion Paper (PDF, 1542 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for HESS
23 Sep 2014
Hydrological drought typology: temperature-related drought types and associated societal impacts
A. F. Van Loon, S. W. Ploum, J. Parajka, A. K. Fleig, E. Garnier, G. Laaha, and H. A. J. Van Lanen Hydrol. Earth Syst. Sci. Discuss., 11, 10465-10514, 2014 AbstractDiscussion Paper (PDF, 1901 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for HESS
19 Sep 2014
Diagnosing the seasonal land–atmosphere coupling strength over Northern Australia: dependence on soil moisture state and coupling strength definition
Integrated assessment of the impact of climate and land use changes on groundwater quantity and quality in Mancha Oriental (Spain)
M. Pulido-Velazquez, S. Peña-Haro, A. Garcia-Prats, A. F. Mocholi-Almudever, L. Henriquez-Dole, H. Macian-Sorribes, and A. Lopez-Nicolas Hydrol. Earth Syst. Sci. Discuss., 11, 10319-10364, 2014 AbstractDiscussion Paper (PDF, 2209 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESSSpecial Issue
17 Sep 2014
Calibration approaches for distributed hydrologic models using high performance computing: implication for streamflow projections under climate change
Terrestrial liming to promote Atlantic Salmon recovery in Nova Scotia – approaches needed and knowledge gained after a trial application
S. M. Sterling, C. Angelidis, M. Armstrong, K. M. Biagi, T. A. Clair, N. Jackson, and A. Breen Hydrol. Earth Syst. Sci. Discuss., 11, 10117-10156, 2014 AbstractDiscussion Paper (PDF, 5722 KB)Supplement (155 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for HESS
05 Sep 2014
Derivation of a new continuous adjustment function for correcting wind-induced loss of solid precipitation: results of a Norwegian field study
M. A. Wolff, K. Isaksen, A. Petersen-Øverleir, K. Ødemark, T. Reitan, and R. Brækkan Hydrol. Earth Syst. Sci. Discuss., 11, 10043-10084, 2014 AbstractDiscussion Paper (PDF, 4464 KB)Interactive Discussion (Open, 8 Comments)Manuscript under review for HESS
01 Sep 2014
Impact of flow velocity on biochemical processes – a laboratory experiment