A Distributed Groundwater/Surface Water Model for the Suså-Catchment

1982 ◽  
Vol 13 (5) ◽  
pp. 299-310 ◽  
Author(s):  
Jens Chr Refsgaard ◽  
Eggert Hansen
Keyword(s):  
Hydrological Cycle ◽  
Root Zone ◽  
Water Model ◽  
Model Description ◽  
Zone Model ◽  
Distributed Hydrological Model ◽  
Groundwater Abstraction ◽  
Moisture Deficit ◽  
Physically Based ◽  
Phreatic Aquifers

A distributed hydrological model has been developed for the Suså catchment, covering about 1,000 km2 of Zealand, Denmark. Being a physically based description of the entire land phase of the hydrological cycle, the model is the result of an integration of an integrated finite difference groundwater model, an aquitard model, a model for unconfined phreatic aquifers and a root zone model. The main objective of the model has been to make possible predictions of the hydrological consequences of groundwater abstraction on the river discharges and on the hydraulic heads of the aquifers. Therefore special attention is given to the interaction between the streams and the aquifers. The model was tested against field data of streamflow, actual evapotranspiration, soil moisture deficit, drain water discharges and hydraulic heads of the confined aquifer. A model description and some results from the calibration and tests are given.

scholarly journals A Distributed Groundwater/Surface Water Model for the Suså-Catchment

1982 ◽  
Vol 13 (5) ◽  
pp. 311-322 ◽  
Author(s):  
Jens Chr Refsgaard ◽  
Eggert Hansen
Keyword(s):  
Surface Water ◽  
Hydrological Cycle ◽  
Water Model ◽  
Confined Aquifer ◽  
Groundwater Abstraction ◽  
Physically Based Model ◽  
Physical Mechanisms ◽  
Physically Based ◽  
Streamflow Data ◽  
Streamflow Depletion

A distributed physically based model of the entire land phase of the hydrological cycle has been developed for the Suså-area, covering about 1,000 km2 of Zealand, Denmark. The model is described in part I of the paper, also presented in this volume. The model's ability to simulate the streamflow depletion caused by a groundwater abstraction from a confined aquifer, overlaid by Quaternary drift deposits, has been tested on historical streamflow data from the catchment of Køge Å. This catchment has been heavily influenced by a major groundwater abstraction started in 1964. The physical mechanisms of streamflow depletion are discussed, and the effects of a groundwater abstraction on the recharge to the confined aquifer and on the streamflow are illustrated. General conclusions regarding streamflow depletion due to groundwater abstraction are made.

An integrated and physically based nitrogen cycle catchment model

2009 ◽  
Vol 40 (4) ◽  
pp. 347-363 ◽  
Author(s):  
J. R. Hansen ◽  
J. C. Refsgaard ◽  
V. Ernstsen ◽  
S. Hansen ◽  
M. Styczen ◽  
...  
Keyword(s):  
Land Use ◽  
Nitrogen Cycle ◽  
Root Zone ◽  
River System ◽  
Zone Model ◽  
Physically Based ◽  
Daily Discharge ◽  
Land Use And Management ◽  
Catchment Model ◽  
Modelling Approach

This paper presents a modelling approach where the entire land-based hydrological and nitrogen cycle from field to river outlet was included. This approach is based on a combination of a physically based root zone model (DAISY) and a physically based distributed catchment model (MIKE SHE/MIKE11). Large amounts of data available from statistical databases and surface maps were used for determination of land use and management practises to predict leaching within the catchment. The modelling approach included a description of nitrate transformations in the root zone, denitrification in the saturated zone, wetland areas and the river system within the catchment. The modelling approach was applied for the Odense Fjord catchment which constitutes one of the pilot river basins for implementation of the European Water Framework Directive. The model simulated overall nitrogen fluxes in the river system consistent with the observed values but showed some discrepancies between simulated and observed daily discharge values The results showed significant differences of denitrification capacities between larger areas such as sub-catchments. This approach has great potential for optimal planning of the establishment of wetlands and further land use legislation with respect to high denitrification rates.

scholarly journals WATBAL

1986 ◽  
Vol 17 (4-5) ◽  
pp. 347-362 ◽  
Author(s):  
J. Knudsen ◽  
A. Thomsen ◽  
J. Chr Refsgaard
Keyword(s):  
Input Data ◽  
Hydrological Cycle ◽  
Root Zone ◽  
Land Use Changes ◽  
Medium Size ◽  
Spatial And Temporal Variability ◽  
Ungauged Catchments ◽  
Conceptual Approach ◽  
Model Type ◽  
Physically Based

A semi-distributed, physically based hydrological modelling system, WATBAL, which accounts for the entire land phase of the hydrological cycle is described. As compared to the two alternative hydrological model types, i.e. the traditional lumped, conceptual rainfall runoff models (STANFORD model type) and the complex, fully distributed, physically based model (SHE model type) WATBAL represents an intermediate approach. In the model, primary attention is given to the hydrological processes at the root zone level through a distributed, physically based approach whereas the groundwater processes are simulated in less details by use of a lumped, conceptual approach. This approach allows WATBAL to utilize spatially distributed input data to account for the spatial and temporal variability of meteorological conditions, vegetation and soil properties. Thus WATBAL can e.g. utilize digital satellite information as input data. WATBAL has primarily been designed as a tool for predicting the runoff from ungauged catchments and for assessing the hydrological effects of land use changes. The capability of the model for simulating ungauged catchments is tested using results from a recent feasibility study for medium size dams in Zimbabwe.

scholarly journals Anthropogenic warming and intraseasonal summer monsoon variability amplify the risk of future flash droughts in India

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Vimal Mishra ◽  
Saran Aadhar ◽  
Shanti Shwarup Mahto
Keyword(s):  
Soil Moisture ◽  
Summer Monsoon ◽  
Crop Production ◽  
Monsoon Rainfall ◽  
Root Zone ◽  
Monsoon Season ◽  
Intraseasonal Variability ◽  
Positive Temperature ◽  
Groundwater Abstraction ◽  
Increased Risk

AbstractFlash droughts cause rapid depletion in root-zone soil moisture and severely affect crop health and irrigation water demands. However, their occurrence and impacts in the current and future climate in India remain unknown. Here we use observations and model simulations from the large ensemble of Community Earth System Model to quantify the risk of flash droughts in India. Root-zone soil moisture simulations conducted using Variable Infiltration Capacity model show that flash droughts predominantly occur during the summer monsoon season (June–September) and driven by the intraseasonal variability of monsoon rainfall. Positive temperature anomalies during the monsoon break rapidly deplete soil moisture, which is further exacerbated by the land-atmospheric feedback. The worst flash drought in the observed (1951–2016) climate occurred in 1979, affecting more than 40% of the country. The frequency of concurrent hot and dry extremes is projected to rise by about five-fold, causing approximately seven-fold increase in flash droughts like 1979 by the end of the 21st century. The increased risk of flash droughts in the future is attributed to intraseasonal variability of the summer monsoon rainfall and anthropogenic warming, which can have deleterious implications for crop production, irrigation demands, and groundwater abstraction in India.

scholarly journals Transient flow between aquifers and surface water: analytically derived field-scale hydraulic heads and fluxes

2012 ◽  
Vol 16 (3) ◽  
pp. 649-669 ◽  
Author(s):  
G. H. de Rooij
Keyword(s):  
Surface Water ◽  
Transient Flow ◽  
Hydrological Cycle ◽  
Realistic Model ◽  
Water Levels ◽  
Subsurface Water ◽  
Water Model ◽  
Infinite Strip ◽  
Catchment Scale ◽  
Basin Scale

Abstract. The increasing importance of catchment-scale and basin-scale models of the hydrological cycle makes it desirable to have a simple, yet physically realistic model for lateral subsurface water flow. As a first building block towards such a model, analytical solutions are presented for horizontal groundwater flow to surface waters held at prescribed water levels for aquifers with parallel and radial flow. The solutions are valid for a wide array of initial and boundary conditions and additions or withdrawals of water, and can handle discharge into as well as lateral infiltration from the surface water. Expressions for the average hydraulic head, the flux to or from the surface water, and the aquifer-scale hydraulic conductivity are developed to provide output at the scale of the modelled system rather than just point-scale values. The upscaled conductivity is time-variant. It does not depend on the magnitude of the flux but is determined by medium properties as well as the external forcings that drive the flow. For the systems studied, with lateral travel distances not exceeding 10 m, the circular aquifers respond very differently from the infinite-strip aquifers. The modelled fluxes are sensitive to the magnitude of the storage coefficient. For phreatic aquifers a value of 0.2 is argued to be representative, but considerable variations are likely. The effect of varying distributions over the day of recharge damps out rapidly; a soil water model that can provide accurate daily totals is preferable over a less accurate model hat correctly estimates the timing of recharge peaks.

scholarly journals Inverse distributed hydrological modelling of Alpine catchments

2006 ◽  
Vol 10 (3) ◽  
pp. 395-412 ◽  
Author(s):  
H. Kunstmann ◽  
J. Krause ◽  
S. Mayr
Keyword(s):  
Parameter Estimation ◽  
Hydrological Model ◽  
Model Performance ◽  
Horizontal Resolution ◽  
Nonlinear Parameter ◽  
Model Complexity ◽  
Distributed Hydrological Model ◽  
Nonlinear Parameter Estimation ◽  
Estimated Parameters ◽  
Physically Based

Abstract. Even in physically based distributed hydrological models, various remaining parameters must be estimated for each sub-catchment. This can involve tremendous effort, especially when the number of sub-catchments is large and the applied hydrological model is computationally expensive. Automatic parameter estimation tools can significantly facilitate the calibration process. Hence, we combined the nonlinear parameter estimation tool PEST with the distributed hydrological model WaSiM. PEST is based on the Gauss-Marquardt-Levenberg method, a gradient-based nonlinear parameter estimation algorithm. WaSiM is a fully distributed hydrological model using physically based algorithms for most of the process descriptions. WaSiM was applied to the alpine/prealpine Ammer River catchment (southern Germany, 710 km2 in a 100×100 m2 horizontal resolution. The catchment is heterogeneous in terms of geology, pedology and land use and shows a complex orography (the difference of elevation is around 1600 m). Using the developed PEST-WaSiM interface, the hydrological model was calibrated by comparing simulated and observed runoff at eight gauges for the hydrologic year 1997 and validated for the hydrologic year 1993. For each sub-catchment four parameters had to be calibrated: the recession constants of direct runoff and interflow, the drainage density, and the hydraulic conductivity of the uppermost aquifer. Additionally, five snowmelt specific parameters were adjusted for the entire catchment. Altogether, 37 parameters had to be calibrated. Additional a priori information (e.g. from flood hydrograph analysis) narrowed the parameter space of the solutions and improved the non-uniqueness of the fitted values. A reasonable quality of fit was achieved. Discrepancies between modelled and observed runoff were also due to the small number of meteorological stations and corresponding interpolation artefacts in the orographically complex terrain. Application of a 2-dimensional numerical groundwater model partly yielded a slight decrease of overall model performance when compared to a simple conceptual groundwater approach. Increased model complexity therefore did not yield in general increased model performance. A detailed covariance analysis was performed allowing to derive confidence bounds for all estimated parameters. The correlation between the estimated parameters was in most cases negligible, showing that parameters were estimated independently from each other.

scholarly journals Hunting for Information in Streamflow Signatures to Improve Modelled Drainage

Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Raphael Schneider ◽  
Simon Stisen ◽  
Anker Lajer Højberg
Keyword(s):  
Large Scale ◽  
Agricultural Land ◽  
Hydrological Cycle ◽  
Drainage System ◽  
Water Model ◽  
Generation Process ◽  
Hydrological Models ◽  
Drainage Patterns ◽  
Drain Flow ◽  
Set Up

About half of the Danish agricultural land is drained artificially. Those drains, mostly in the form of tile drains, have a significant effect on the hydrological cycle. Consequently, the drainage system must also be represented in hydrological models that are used to simulate, for example, the transport and retention of chemicals. However, representation of drainage in large-scale hydrological models is challenging due to scale issues, lacking data on the distribution of drain infrastructure, and lacking drain flow observations. This calls for more indirect methods to inform such models. Here, we investigate the hypothesis that drain flow leaves a signal in streamflow signatures, as it represents a distinct streamflow generation process. Streamflow signatures are indices characterizing hydrological behaviour based on the hydrograph. Using machine learning regressors, we show that there is a correlation between signatures of simulated streamflow and simulated drain fraction. Based on these insights, signatures relevant to drain flow are incorporated in hydrological model calibration. A distributed coupled groundwater–surface water model of the Norsminde catchment, Denmark (145 km2) is set up. Calibration scenarios are defined with different objective functions; either using conventional stream flow metrics only, or a combination with hydrological signatures. We then evaluate the results from the different scenarios in terms of how well the models reproduce observed drain flow and spatial drainage patterns. Overall, the simulation of drain in the models is satisfactory. However, it remains challenging to find a direct link between signatures and an improvement in representation of drainage. This is likely attributable to model structural issues and lacking flexibility in model parameterization.

scholarly journals Evaluation of radar-based precipitation estimates for flash flood forecasting in the Three Gorges Region

2015 ◽  
Vol 368 ◽  
pp. 89-95 ◽  
Author(s):  
Z. Li ◽  
D. Yang ◽  
Y. Hong ◽  
Y. Qi ◽  
Q. Cao
Keyword(s):  
Flash Flood ◽  
Critical Role ◽  
Flood Forecasting ◽  
Three Gorges ◽  
Distributed Hydrological Model ◽  
Ground Clutter ◽  
Three Gorges Region ◽  
Physically Based ◽  
Precipitation Estimation ◽  
Flash Flood Forecasting

Abstract. Spatial rainfall pattern plays a critical role in determining hydrological responses in mountainous areas, especially for natural disasters such as flash floods. In this study, to improve the skills of flood forecasting in the mountainous Three Gorges Region (TGR) of the Yangtze River, we developed a first version of a high-resolution (1 km) radar-based quantitative precipitation estimation (QPE) consideration of many critical procedures, such as beam blockage analysis, ground-clutter filter, rain type identification and adaptive Z–R relations. A physically-based distributed hydrological model (GBHM) was established and further applied to evaluate the performance of radar-based QPE for regional flood forecasting, relative to the gauge-driven simulations. With two sets of input data (gauge and radar) collected during summer 2010, the applicability of the current radar-based QPE to rainstorm monitoring and flash flood forecasting in the TGR is quantitatively analysed and discussed.

The Pesticide Root Zone Model (PRZM): A procedure for evaluating pesticide leaching threats to groundwater

1985 ◽  
Vol 30 (1-2) ◽  
pp. 49-69 ◽  
Author(s):  
Robert F. Carsel ◽  
Lee A. Mulkey ◽  
Matthew N. Lorber ◽  
Leland B. Baskin
Keyword(s):  
Root Zone ◽  
Zone Model ◽  
Pesticide Leaching
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