Influence of solar forcing, climate variability and atmospheric circulation patterns 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 Summer North Atlantic Oscillation.
Actual evapotranspiration and precipitation measured by lysimeters: a comparison with eddy covariance and tipping bucket
S. Gebler, H.-J. Hendricks Franssen, T. Pütz, H. Post, M. Schmidt, and H. Vereecken Hydrol. Earth Syst. Sci. Discuss., 11, 13797-13841, 2014 AbstractDiscussion Paper (PDF, 4271 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
17 Dec 2014
Exploring the impact of forcing error characteristics on physically based snow simulations within a global sensitivity analysis framework
Summary: Sensitivity analysis is used to examine how error characteristics (type, distributions, and magnitudes) in meteorological forcing data impact four 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. The forcing uncertainty found here exceeded model selection uncertainty found in other studies.
Dye tracing for investigating flow and transport properties of hydrocarbon-polluted Rabots glaciär, Kebnekaise, Sweden
C. C. Clason, C. Coch, J. Jarsjö, K. Brugger, P. Jansson, and G. Rosqvist Hydrol. Earth Syst. Sci. Discuss., 11, 13711-13744, 2014 AbstractDiscussion Paper (PDF, 2836 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
15 Dec 2014
Complex networks, streamflow, and hydrometric monitoring system design
Extending periodic eddy covariance latent heat fluxes through tree sapflow measurements to estimate long-term total evaporation in a peat swamp forest
Summary: The 3rd paper in a series dealing with evaporation over indigenous vegetation in an area of South Africa experiencing severe water challenges. The area is a World Heritage site and an important conservation area in which our understanding of the water-balance plays a crucial role in system management.
We provide the fist estimates of total evaporation from a subtropical peat swamp forest, investigate measurement techniques and provide modelling solutions to estimate long-term evaporation.
A. D. Clulow, C. S. Everson, M. G. Mengistu, J. S. Price, A. Nickless, and G. P. W. Jewitt Hydrol. Earth Syst. Sci. Discuss., 11, 13607-13661, 2014 AbstractDiscussion Paper (PDF, 2412 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
12 Dec 2014
Effects of vegetation change on evapotranspiration in a semiarid shrubland of the Loess Plateau, China
Evaluation of an extreme-condition-inverse calibration remote sensing model for mapping energy balance fluxes in arid riparian areas
S.-H. Hong, J. M. H. Hendrickx, J. Kleissl, R. G. Allen, W. G. M. Bastiaanssen, R. L. Scott, and A. L. Steinwand Hydrol. Earth Syst. Sci. Discuss., 11, 13479-13539, 2014 AbstractDiscussion Paper (PDF, 2739 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
10 Dec 2014
Virtual laboratories: new opportunities for collaborative water science
Summary: We present the outcomes of a collaborative hydrological experiment undertaken by five different international research groups in a virtual laboratory. Moving from the definition of accurate protocols, a rainfall-runoff model was independently applied by the research groups, which then engaged in a comparative discussion. The results revealed that sharing protocols and running the experiment within a controlled environment is fundamental for ensuring experiment repeatability and reproducibility.
S. Ceola, B. Arheimer, G. Blöschl, E. Baratti, R. Capell, A. Castellarin, J. Freer, D. Han, M. Hrachowitz, Y. Hundecha, C. Hutton, G. Lindström, A. Montanari, R. Nijzink, J. Parajka, E. Toth, A. Viglione, and T. Wagener Hydrol. Earth Syst. Sci. Discuss., 11, 13443-13478, 2014 AbstractDiscussion Paper (PDF, 3418 KB)Supplement (98 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
10 Dec 2014
Diagnostic calibration of a hydrological model in an alpine area by hydrograph partitioning
Monitoring and modelling of soil–plant interactions: the joint use of ERT, sap flow and Eddy Covariance data to characterize the volume of an orange tree root zone
Summary: The paper presents an integrated approach to monitoring root water uptake and link this information to the plant transpiration measured by sap flow and eddy covariance. The monitoring of soil conditions is achieved using 3-D electrical resistivity tomography. This ensemble of data can be used jointly to model the soil-plant interactions and identify the extent and efficiency of the root zone in front of existing irrigation schemes. A case study is presented regarding an orange orchard in Sicily.
G. Cassiani, J. Boaga, D. Vanella, M. T. Perri, and S. Consoli Hydrol. Earth Syst. Sci. Discuss., 11, 13353-13384, 2014 AbstractDiscussion Paper (PDF, 21091 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
08 Dec 2014
Notes on the estimation of resistance to flow during flood wave propagation
Summary: The paper discusses the evaluation of resistance in unsteady flow, which still poses a challenge. It is shown that physically based variables such as friction velocity are better indicators of resistance variability during flood wave propagation than empirical coefficients, such as the Manning coefficient, which were originally derived for steady flow conditions. Theoretical description is facilitated with the analysis of field data from artificial dam-break flood waves in a small lowland river.
From runoff to rainfall: inverse rainfall–runoff modelling in a high temporal resolution
Summary: Especially in alpine catchments, areal rainfall estimates often exhibit large errors. Runoff measurements are on the other hand one of the most robust observations within the hydrological cycle. We therefore calculate mean catchment rainfall by inverting a HBV-type rainfall-runoff model, using runoff observations as input. The inverse model can e.g. be used to analyse the rainfall conditions of extreme flood events.
A global dataset of the extent of irrigated land from 1900 to 2005
Summary: We developed the Historical Irrigation Dataset (HID) depicting the temporal development of the area equipped for irrigation (AEI) between 1900 and 2005 at 5 arc-minute resolution.
The HID reflects very well the spatial patterns of irrigated land in the western USA as shown on historical maps.
Global AEI increased from 63 million ha (Mha) in 1900 to 112 Mha in 1950 and 306 Mha in 2005. Mean aridity on irrigated land increased and mean natural river discharge decreased from 1900–1950.
Testing gridded land precipitation data and precipitation and runoff reanalyses (1982–2010) between 45° S and 45° N with Normalized Difference Vegetation Index data
Summary: The study evaluates annual precipitation (largely rainfall) amounts for the tropics and subtropics; precipitation amounts were obtained from ground observations, satellite observations and numerical weather forecasting models.
- annual precipitation amounts from ground and satellite observations were the most realistic
- newer weather forecasting models better predicted annual precipitation than an older model
- weather forecasting models predicted inaccurate precipitation amounts for Africa
Quantification of the influence of preferential flow on slope stability using a numerical modeling approach
Summary: The effect of preferential flow on the stability of landslides is studied through numerical simulation of two types of rainfall events on a hypothetical hillslope. A model is developed that consists of two parts. The first part is a model for combined saturated/unsaturated subsurface flow and is used to compute the spatial and temporal water pressure response to rainfall. Preferential flow is simulated with a dual-permeability continuum model consisting of a matrix domain coupled to a preferenti
Assessing downstream flood impacts due to a potential GLOF from Imja Lake in Nepal
Summary: The potential flooding impacts from Imja glacial lake in Nepal were studied using a two-dimensional debris flow model to evaluate the effectiveness of proposed measures to reduce possible flooding impacts to downstream communities by lowering the lake level. The results indicate that only minor benefits is achieved with modest (~3 m) lowering and lowering of 20 m almost eliminates all flood impact at Dingboche.
M. A. Somos-Valenzuela, D. C. McKinney, A. C. Byers, D. R. Rounce, C. Portocarrero, and D. Lamsal Hydrol. Earth Syst. Sci. Discuss., 11, 13019-13053, 2014 AbstractDiscussion Paper (PDF, 4478 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for HESS
25 Nov 2014
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, 1 Comment)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, 2 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, 2 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, 3 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, 2 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, 4 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, 2 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, 1 Comment)Manuscript under review for HESS
24 Oct 2014
Technical Note: Surface water velocity observations from a camera: a case study on the Tiber River
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, 1 Comment)Manuscript under review for HESS
23 Oct 2014
Performance and robustness of probabilistic river forecasts computed with quantile regression based on multiple independent variables in the North Central USA
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
Contribution of the Multi Attribute Value Theory to conflict resolution in groundwater management. Application to the Mancha Oriental groundwater system, Spain
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
Impact of flow velocity on biochemical processes – a laboratory experiment