Integrated water system simulation by considering hydrological and biogeochemical processes: model development, parameter sensitivity and autocalibration
Summary: We extended a semi-distributed hydrological model (TVGM) to an integrated water system model by coupling multiple water-related processes in hydrology, biogeochemistry, water quality and ecology, and considering the interference of human activities. The parameter sensitivity and autocalibration modules were developed to improve the simulation efficiency. The extended model was applied in the Shaying River Catchment, which is a highly regulated and heavily polluted region in China.
Hydrol. Earth Syst. Sci. Discuss., 12, 4997-5053, doi:10.5194/hessd-12-4997-2015, 2015
Rainfall erosivity estimation based on rainfall data collected over a range of temporal resolutions
Hydrol. Earth Syst. Sci. Discuss., 12, 4965-4996, doi:10.5194/hessd-12-4965-2015, 2015
Estimation of crop water requirements: extending the one-step approach to dual crop coefficients
Hydrol. Earth Syst. Sci. Discuss., 12, 4933-4963, doi:10.5194/hessd-12-4933-2015, 2015
A method for calculating the duration and intensity of salt intrusions: the Yangtze River estuary
Summary: This paper demonstrates a method for calculating the probability of long duration salt intrusions in the Yangtze estuary. The relationship between river discharge and the intensity and duration of saline intrusions is shown to be probabilistic and continuous. For periods like 1950–2014, in a quarter of years saline intrusions (chlorinity ≥ 250 mg / L) of at least 30 days have a one in ten chance of occurring. Intrusions that can disrupt the supply of water to local residents are not rare.
Hydrol. Earth Syst. Sci. Discuss., 12, 4909-4932, doi:10.5194/hessd-12-4909-2015, 2015
Annual canopy interception at artificial lowland tropical forest
Summary: A study has developed a simple model to estimate annual interception loss with temporal resolution effects. The model required minimum input and the amount of the interception loss from an artificial lowland tropical forest was determine with this model. The interception values has been compared with results calculated using original Gash model, modified Gash model and measured data. The findings show that the model can be applied to estimate the interception loss with 0.18 to 2.71% differences.
Hydrol. Earth Syst. Sci. Discuss., 12, 4879-4907, doi:10.5194/hessd-12-4879-2015, 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 of 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 has increased its utilization The review is on modelling, mapping with RS
Hydrol. Earth Syst. Sci. Discuss., 12, 4857-4878, doi:10.5194/hessd-12-4857-2015, 2015
Kalman filter approach for estimating water level time series over inland water using multi-mission satellite altimetry
Hydrol. Earth Syst. Sci. Discuss., 12, 4813-4855, doi:10.5194/hessd-12-4813-2015, 2015
Effects of mountain agriculture on nutrient cycling at upstream watersheds
Summary: We summarized the findings below: 1. The mountain watersheds are vulnerable to agriculture expansion. 2. Proper spatial configuration of agricultural lands in mountain watersheds can mitigate the impact of agriculture on NO3- output by 70%. 3. The re-constructed element fluxes for the watersheds indicate excessive leaching of N and P, and additional loss of N to the atmosphere via volatilization and denitrification, which likely resulted from excessive fertilizer use.
Hydrol. Earth Syst. Sci. Discuss., 12, 4785-4811, doi:10.5194/hessd-12-4785-2015, 2015
Reconciling high altitude precipitation in the upper Indus Basin with glacier mass balances and runoff
Hydrol. Earth Syst. Sci. Discuss., 12, 4755-4784, doi:10.5194/hessd-12-4755-2015, 2015
Groundwater-dependent ecosystems: recent insights, new techniques and an ecosystem-scale threshold response
Summary: In this review, we discuss a range of techniques, including remote sensing, for identifying groundwater dependent ecosystems and determining rates of water use by GDEs. In addition, gravity recovery satellite data are discussed in relation to changes in soil and groundwater stores. Ecophysiological and structural attributes of GDEs are reviewed, from which we present an integrated ecosystem-scale response as a function of differences in depth to groundwater.
Hydrol. Earth Syst. Sci. Discuss., 12, 4677-4754, doi:10.5194/hessd-12-4677-2015, 2015
High-resolution modelling of interactions between soil moisture and convection development in 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. Discuss., 12, 4631-4675, doi:10.5194/hessd-12-4631-2015, 2015
A global approach to defining flood seasons
Summary: This paper presents a global approach to defining flood seasons. Simulations of streamflow from the PCR-GLOBWB model are evaluated to define dominant and minor flood seasons globally, and verified with GRDC observations and flood records from Dartmouth Flood Observatory. The defined flood seasons link global and regional climate behavior with seasonal spatial and temporal patterns of streamflow, providing further prospects for developing season-ahead flood prediction models.
Hydrol. Earth Syst. Sci. Discuss., 12, 4595-4630, doi:10.5194/hessd-12-4595-2015, 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 quantifying the cost and benefit of nature conservation in terms of groundwater recharge.
Hydrol. Earth Syst. Sci. Discuss., 12, 4541-4594, doi:10.5194/hessd-12-4541-2015, 2015
An index of floodplain surface complexity
Summary: An index of floodplain surface complexity is developed in this paper and applied to eight floodplains from different geographic settings. Floodplain width and sediment yield were associated with the index, or with sub-indicators; whereas, hydrology was not. These findings suggest that valley and sediment conditions are important determinants of floodplain surface complexity, and these should complement hydrology as a focus of floodplain research and management.
Hydrol. Earth Syst. Sci. Discuss., 12, 4507-4540, doi:10.5194/hessd-12-4507-2015, 2015
Variability in snow cover phenology in China from 1952 to 2010
Summary: The heavy-snow years in China include 1955, 1957, 1964, and 2010, and light-snow years include 1953, 1965, 1999, 2002, and 2009. The reduction in number of days with temperature below 0°C and increase in mean air temperature are the main reasons for the delay of snow cover onset date and advance of snow cover end date. This explains why only 15% of the stations show significant shortening of snow cover day, and differs with the overall shortening of the snow period in the Northern Hemisphere.
Hydrol. Earth Syst. Sci. Discuss., 12, 4471-4506, doi:10.5194/hessd-12-4471-2015, 2015
Quantitative historical hydrology in Europe
Summary: Historical hydrology combines documentary data with hydrological methods to lengthen flow records to the past centuries. We describe the methodological evolution of historical hydrology under the influence of developments in hydraulics and statistics. Analysis of 45 case studies in Europe show that present flood magnitudes are not unusual in the context of the past, whereas flood frequency has decreased, although some rivers show a reactivation of rare floods over the last two decades.
Hydrol. Earth Syst. Sci. Discuss., 12, 4413-4469, doi:10.5194/hessd-12-4413-2015, 2015
Spatial and temporal runoff processes in the degraded Ethiopian Highlands: the Anjeni Watershed
Hydrol. Earth Syst. Sci. Discuss., 12, 4387-4411, doi:10.5194/hessd-12-4387-2015, 2015
Climate model uncertainty vs. 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. Discuss., 12, 4353-4385, doi:10.5194/hessd-12-4353-2015, 2015
Modelling water, sediment and nutrient fluxes from a mixed land-use catchment in New Zealand: effects of hydrologic conditions on SWAT model performance
Summary: This study examined the applicability of the SWAT model to a moderately steep, temperate, small–sized catchment in Rotorua, New Zealand. It highlighted the importance of using high–frequency, event–based monitoring data for model calibration, to alleviate the potential of underestimation of storm–driven fluxes. Parameter sensitivity was quantified for discharge, sediment and nutrient fluxes dependent on the relative dominance of base flow and quick flow.
Hydrol. Earth Syst. Sci. Discuss., 12, 4315-4352, doi:10.5194/hessd-12-4315-2015, 2015
What are the key drivers of regional differences in the water balance on the Tibetan Plateau?
Summary: In this study, the hydrological model J2000g was extended and applied to endorheic lake basins on the TP aiming to provide a more quantitative understanding of the key factors controlling the water-balance on the TP. The model results indicated that the relative contribution of glacier runoff to total water inflow (between 15-30 %) plays a relatively minor role, compared to precipitation and snowmelt runoff components from non-glacierized areas.
Hydrol. Earth Syst. Sci. Discuss., 12, 4271-4314, doi:10.5194/hessd-12-4271-2015, 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. Discuss., 12, 4233-4270, doi:10.5194/hessd-12-4233-2015, 2015
Updating hydraulic properties and layer thicknesses in hydrogeological models using groundwater model calibration results
Summary: We present a method to find the most likely properties (layer thickness and conductivity) for each litho-class of the constituting layers of an aquitard, using a readily calibrated groundwater model. The prior litho-class properties are uncertain, and based on borehole data. The groundwater model parameters are assumed to be the truth. The combination of prior data and calibration result yields the most likely litho-class properties. The method is applicable to aquifers as well.
Hydrol. Earth Syst. Sci. Discuss., 12, 4191-4231, doi:10.5194/hessd-12-4191-2015, 2015
Uncertainty analysis for evaluating the accuracy of snow depth measurements
Hydrol. Earth Syst. Sci. Discuss., 12, 4157-4190, doi:10.5194/hessd-12-4157-2015, 2015
Stream temperature prediction in ungauged basins: review of recent approaches and description of a new physically-based analytical model
Summary: This study presents a new model to estimate the monthly mean stream temperature of ungauged rivers over multiple years in an Alpine country. Contrary to the statistical approaches developed to date, which are usually based on regression techniques, our model makes use of the understanding that we have about the physics controlling stream temperature. On top of its accuracy being comparable to that of the other models, it can be used to gain some knowledge about the stream temperature dynamics.
Hydrol. Earth Syst. Sci. Discuss., 12, 4081-4155, doi:10.5194/hessd-12-4081-2015, 2015
The Global Network of Isotopes in Rivers (GNIR): integration of water isotopes in watershed observation and riverine research
Summary: We introduce a new online global database of riverine water stable isotopes (Global Network of Isotopes in Rivers) and evaluate its longer-term data holdings. A regionalized, cluster-based precipitation isotope model was used to compare measured to predicted isotope compositions of riverine catchments. The study demonstrated that the seasonal isotopic composition and variation of river water can be predicted, which will improve the application of water stable isotopes in rivers.
Hydrol. Earth Syst. Sci. Discuss., 12, 4047-4079, doi:10.5194/hessd-12-4047-2015, 2015
Climatological characteristics of raindrop size distributions within a topographically complex area
Hydrol. Earth Syst. Sci. Discuss., 12, 4005-4045, doi:10.5194/hessd-12-4005-2015, 2015
Hydrological model parameter dimensionality is a weak measure of prediction uncertainty
Hydrol. Earth Syst. Sci. Discuss., 12, 3945-4004, doi:10.5194/hessd-12-3945-2015, 2015
Effects of changes in moisture source and the upstream rainout on stable isotopes in summer precipitation – a case study in Nanjing, East China
Summary: We examined the variability of daily stable isotopic composition (δ18O) in summer precipitation in Nanjing, East China. We found that δ18O was not significantly correlated with local rainfall amount, but could be linked to changes in the location and rainout processes of precipitation source regions. Thus, changes in moisture source location and upstream rainout effect should be taken into account when interpreting the stable isotopic composition of speleothems in the Asian monsoon region.
Hydrol. Earth Syst. Sci. Discuss., 12, 3919-3944, doi:10.5194/hessd-12-3919-2015, 2015
Long-term and high frequency non-destructive monitoring of water stable isotope profiles in an evaporating soil column
Summary: Water stable isotopes profiles in a soil column let to evaporate for a period of 290 days in the laboratory were followed in a non-destructive manner and with high precision Rewatering at the end of the experiment led to instantaneous resetting of the stable isotope profiles, which could be closely followed with the new method We observed the progressive invasion of atmosphere water vapor in the upper soil layers The evaporation depth dynamics was determined from isotope gradients calculation
Hydrol. Earth Syst. Sci. Discuss., 12, 3893-3918, doi:10.5194/hessd-12-3893-2015, 2015
Reconstructing the natural hydrology of the San Francisco Bay-Delta watershed
Summary: The development of California was facilitated by redistributing water from native vegetation to other uses, accompanied by significant declines in native aquatic species, which have been attributed to reductions in Delta outflow. Reconstructing the natural landscape and using water balances to estimate long-term annual average Delta outflow, current and natural outflows are about equal as the amount of water currently consumed is similar to the amount of water formerly used by native vegetation.
Hydrol. Earth Syst. Sci. Discuss., 12, 3847-3892, doi:10.5194/hessd-12-3847-2015, 2015
Stochastic approach to analyzing the uncertainties and possible changes in the availability of water in the future based on a climate change scenario
Summary: The objective of this study was to analyze the changes and uncertainties related to water availability in the future, in the Ijuí river basin (south of Brazil), using a stochastic approach. In general the results showed a trend to increased flows. It can be concluded that there is a tendency to increase the hydrological variability during the period between 2011-2040, which indicates the possibility of occurrence of time series with more marked periods of droughts and floods.
Hydrol. Earth Syst. Sci. Discuss., 12, 3787-3846, doi:10.5194/hessd-12-3787-2015, 2015
Improving multi-objective reservoir operation optimization with sensitivity-informed problem decomposition
Summary: This study investigates the effectiveness of a sensitivity-informed method for multi-objective operation of reservoir systems, which uses a global sensitivity analysis method to screen out insensitive decision variables and thus forms simplified problems with a significantly reduced number of decision variables. We find that it is important to consider variable interactions when formulating simplified problems, and problem decomposition dramatically improves search efficiency and effectiveness.
Hydrol. Earth Syst. Sci. Discuss., 12, 3719-3752, doi:10.5194/hessd-12-3719-2015, 2015
Identification of spatial and temporal contributions of rainfalls to flash floods using neural network modelling: case study on the Lez Basin (Southern France)
Summary: Flash floods are important hazards in urbanised zone and constitute important human and financial stakes. This paper applies a recent methodology (KnoX) dedicated to extract knowledge from a neural network model in order to better know the contributions and time responses of several geographic zones of an aquifer. A case study is chosen in France: the Lez karst hydrosystem whose river crosses the conurbation of Montpellier (400 000 inhabitants). Results will help flood warning service.
Hydrol. Earth Syst. Sci. Discuss., 12, 3681-3718, doi:10.5194/hessd-12-3681-2015, 2015
Climate elasticity of streamflow revisited – an elasticity index based on long-term hydrometeorological records
Summary: We present a new method to derive the empirical (i.e., data-based) elasticity of streamflow to precipitation and potential evaporation. This method, which uses long-term hydrometeorological records, is tested on a set of 519 French catchments. We compare our method with the classical approach found in the literature and demonstrate its robustness and efficiency. Empirical elasticity is a powerful tool to test the extrapolation capacity of hydrological models.
Hydrol. Earth Syst. Sci. Discuss., 12, 3645-3679, doi:10.5194/hessd-12-3645-2015, 2015
Water savings potentials of irrigation systems: dynamic global simulation
Summary: We present dynamically simulated estimates of global irrigation efficiencies for the world’s major crop types. Hence, 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. Discuss., 12, 3593-3644, doi:10.5194/hessd-12-3593-2015, 2015
Predicting land use and soil controls on erosion and sediment redistribution in agricultural loess areas: model development and cross scale verification
Summary: This paper presents the development, parameterization and verification of a process-based soil erosion model for the catchment scale, which balances necessary complexity with greatest possible simplicity. We used the hydrologic model CATFLOW as a platform and further developed it to CATFLOW-SED by integrating approaches to simulate soil erosion. The model was validated on a hierarchy of scales which is characteristic for the governing processes.
Hydrol. Earth Syst. Sci. Discuss., 12, 3527-3592, doi:10.5194/hessd-12-3527-2015, 2015
Towards ecosystem accounting: a comprehensive approach to modelling multiple hydrological ecosystem services
Summary: Our study shows that integrating hydrological ecosystem services in an ecosystem accounting framework provides relevant information on watershed ecosystems and hydrological ecosystem services at appropriate scales suitable for decision-making. They show that for watershed management, land use planning and land management, measurement of ecosystem service flow should go hand in hand with managing ecosystem service capacity.
Hydrol. Earth Syst. Sci. Discuss., 12, 3477-3526, doi:10.5194/hessd-12-3477-2015, 2015
Non–stationarity in annual maxima rainfall across Australia – implications for Intensity–Frequency–Duration (IFD) relationships
Summary: Rainfall intensity-frequency-duration (IFD) relationships are required for the design and planning of water supply and management systems around the world. Currently IFD information is based on the ‘stationary climate assumption’. However, this study provides proof of non-stationarity in annual maxima rainfall timeseries. Importantly, current IFD relationships may under- or over-estimate the design rainfall.
Hydrol. Earth Syst. Sci. Discuss., 12, 3449-3475, doi:10.5194/hessd-12-3449-2015, 2015
A 2600 year history of floods in the Bernese Alps, Switzerland: frequencies, mechanisms and climate forcing
Summary: A 2600-yr 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. Discuss., 12, 3391-3448, doi:10.5194/hessd-12-3391-2015, 2015
Phosphorus dynamics in lowland streams as a response to climatic, hydrological and agricultural land use gradients
Summary: We evaluated the effects of agricultural intensification (AI) on the concentrations and export of phosphorus (P) in four streams under contrasting climate (C: temperate and subtropical) and hydrological (H: stable and flashy) regimes, while comparing different estimation methods. The impact of AI differed between the contrasting C-H regimes. The observed patterns seem to reflect effects of different environmental regulations of agriculture, currently being more important than other factors.
Hydrol. Earth Syst. Sci. Discuss., 12, 3349-3390, doi:10.5194/hessd-12-3349-2015, 2015
Soil moisture–precipitation coupling: observations from the Oklahoma Mesonet and underlying physical mechanisms
Hydrol. Earth Syst. Sci. Discuss., 12, 3205-3243, doi:10.5194/hessd-12-3205-2015, 2015
Aggregation in environmental systems: catchment mean transit times and young water fractions under hydrologic nonstationarity
Hydrol. Earth Syst. Sci. Discuss., 12, 3105-3167, doi:10.5194/hessd-12-3105-2015, 2015
Aggregation in environmental systems: seasonal tracer cycles quantify young water fractions, but not mean transit times, in spatially heterogeneous catchments
Hydrol. Earth Syst. Sci. Discuss., 12, 3059-3103, doi:10.5194/hessd-12-3059-2015, 2015
On the spatial organization of the ridge slough patterned landscape
Hydrol. Earth Syst. Sci. Discuss., 12, 2975-3010, doi:10.5194/hessd-12-2975-2015, 2015
Use of satellite and modelled 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 modelled data and satellite observations obtained from the Advanced SCATterometer (ASCAT). SM4E is found to outperform USLE and USLE-MM models in a 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. Discuss., 12, 2945-2973, doi:10.5194/hessd-12-2945-2015, 2015
Downscaling future precipitation extremes to urban hydrology scales using a spatio-temporal Neyman–Scott weather generator
Hydrol. Earth Syst. Sci. Discuss., 12, 2561-2605, doi:10.5194/hessd-12-2561-2015, 2015
Spatially shifting temporal points: estimating pooled within-time series variograms for scarce hydrological data
Summary: We developed an alternative method (SSTP) for estimating pooled variograms for geostatistical interpolation of spatially scarce hydrological data. The method relies on the availability of time series and spatializes temporal data by shifting them. We applied SSTP for geostatistical interpolation of a precipitation series in a spatial data-scarce region. SSTP outperforms the available method (AEV) for estimating pooled variograms. We provide an example R script with test data for reproducibility.
Hydrol. Earth Syst. Sci. Discuss., 12, 2243-2265, doi:10.5194/hessd-12-2243-2015, 2015
5 year radar-based rainfall statistics: disturbances analysis and development of a post-correction scheme for the German radar composite
Hydrol. Earth Syst. Sci. Discuss., 12, 1765-1808, doi:10.5194/hessd-12-1765-2015, 2015
Spatially-distributed influence of agro-environmental factors governing nitrate fate and transport in an irrigated stream-aquifer system
Summary: Nitrate contamination in agricultural groundwater systems is a concern in many regions worldwide. In this study, a model is applied to a regional-scale irrigated stream-aquifer system to identify the system inputs and processes that govern nitrate fate and transport at multiple scales: for the entire study region, for spatial areas irrigated by individual canals, and for individual cultivated fields. Results can be used to guide the localized application of best management practices.
Hydrol. Earth Syst. Sci. Discuss., 12, 1653-1696, doi:10.5194/hessd-12-1653-2015, 2015
High-quality observation of surface imperviousness for urban runoff modelling using UAV imagery
Summary: We investigate for the first time the possibility to derive high-resolution imperviousness maps for urban areas from UAV imagery and to use this information as input for urban drainage models. We show that imperviousness maps generated using UAV imagery processed with modern classification methods achieve accuracy comparable with standard, off-the-shelf aerial imagery. We conclude that UAV imagery represents a valuable alternative data source for urban drainage model applications.
Hydrol. Earth Syst. Sci. Discuss., 12, 1205-1245, doi:10.5194/hessd-12-1205-2015, 2015
Analysis of frequency and duration of the functional periods on the basis of long-term variability of limnetic processes within the Bug River valley
Hydrol. Earth Syst. Sci. Discuss., 11, 13145-13174, doi:10.5194/hessd-11-13145-2014, 2014
The effective porosity and grain size relations in permeability functions
Hydrol. Earth Syst. Sci. Discuss., 11, 6675-6714, doi:10.5194/hessd-11-6675-2014, 2014