Extending a Large-scale Model to Better Represent Water Resources without Increasing the Model Complexity

A robust hydrological assessment is challenging in regions where human interference, within all aspects of the hydrological system, significantly alters the flow regime of rivers. The challenge was to extend a large-scale water resources model, GWAVA, to better represent water resources without increasing the model complexity. A groundwater and a regulated reservoir routine were incorporated into GWAVA using modifications of the existing AMBHAS-1D and Hanasaki methodologies, respectively. The groundwater routine can be varied in complexity when sufficient input data is available but fundamentally is driven by three input parameters. The reservoir routine was extended to account for the presence of large, regulated reservoirs using two calibratable parameters. The additional groundwater processes and reservoir regulation was tested in two highly anthropogenically influenced basins in India: the Cauvery and Narmada. The inclusion of the revised groundwater routine improved the simulation of streamflow in the headwater catchments and was successful in improving the representation of the baseflow component. In addition, the model was able to produce a time series of daily groundwater levels, recharge to groundwater and groundwater abstraction. The regulated reservoir routine improved the simulation of streamflow in catchments downstream of major reservoirs, where the streamflow was largely reflective of reservoir releases, when calibrated using downstream observed streamflow records. The model was able to provide a more robust representation of the annual volume and daily outflow released from the major reservoirs and simulate the major reservoir storages adequately. The addition of one-dimensional groundwater processes and a regulated reservoir routine proved successful in improving the model performance and traceability of water balance components, without excessively increasing the model complexity and input data requirements.

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Extending a Large-Scale Model to Better Represent Water Resources without Increasing the Model’s Complexity

Water ◽

10.3390/w13213067 ◽

2021 ◽

Vol 13 (21) ◽

pp. 3067

Author(s):

Robyn Horan ◽

Nathan J. Rickards ◽

Alexandra Kaelin ◽

Helen E. Baron ◽

Thomas Thomas ◽

...

Keyword(s):

Large Scale ◽

Model Performance ◽

Data Availability ◽

Model Complexity ◽

Low Flow ◽

Scale Model ◽

Water Balance Components ◽

Large Scale Model ◽

Scale Models ◽

Availability Assessment

The increasing impact of anthropogenic interference on river basins has facilitated the development of the representation of human influences in large-scale models. The representation of groundwater and large reservoirs have realised significant developments recently. Groundwater and reservoir representation in the Global Water Availability Assessment (GWAVA) model have been improved, critically, with a minimal increase in model complexity and data input requirements, in keeping with the model’s applicability to regions with low-data availability. The increased functionality was assessed in two highly anthropogenically influenced basins. A revised groundwater routine was incorporated into GWAVA, which is fundamentally driven by three input parameters, and improved the simulation of streamflow and baseflow in the headwater catchments such that low-flow model skill increased 33–67% in the Cauvery and 66–100% in the Narmada. The existing reservoir routine was extended and improved the simulation of streamflow in catchments downstream of major reservoirs, using two calibratable parameters. The model performance was improved between 15% and 30% in the Cauvery and 7–30% in the Narmada, with the daily reservoir releases in the Cauvery improving significantly between 26% and 164%. The improvement of the groundwater and reservoir routines in GWAVA proved successful in improving the model performance, and the inclusions allowed for improved traceability of simulated water balance components. This study illustrates that improvement in the representation of human–water interactions in large-scale models is possible, without excessively increasing the model complexity and input data requirements.

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The Effects of Scaling and Model Complexity in Simulating the Transport of Inorganic Micropollutants in a Lowland River Reach

Water Quality Research Journal ◽

10.2166/wqrj.2006.003 ◽

2006 ◽

Vol 41 (1) ◽

pp. 24-36 ◽

Cited By ~ 10

Author(s):

Karl-Erich Lindenschmidt ◽

René Wodrich ◽

Cornelia Hesse

Keyword(s):

Large Scale ◽

Transport Model ◽

Transport Processes ◽

Model Complexity ◽

Scale Model ◽

Small Scale ◽

Quality Model ◽

Large Scale Model ◽

Iron And Zinc ◽

Physical And Chemical

Abstract A hypothesis stating that more complex descriptions of processes in models simulate reality better (less error) but with more unreliable predictability (more sensitivity) is tested using a river water quality model. This hypothesis was extended stating that applying the model on a domain of smaller scale requires greater complexity to capture the same accuracy as in large-scale model applications which, however, leads to increased model sensitivity. The sediment and pollutant transport model TOXI, a module in the WASP5 package, was applied to two case studies of different scale: a 90-km course of the 5th order (sensu Strahler 1952) lower Saale river, Germany (large scale), and the lock-and-weir system at Calbe (small scale) situated on the same river course. A sensitivity analysis of several parameters relating to the physical and chemical transport processes of suspended solids, chloride, arsenic, iron and zinc shows that the coefficient, which partitions the total heavy metal mass into its dissolved and sorbed fraction, is a very sensitive parameter. Hence, the complexity of the sorptive process was varied to test the hypotheses.

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Issues of diffuse pollution model complexity arising from performance benchmarking

Hydrology and Earth System Sciences ◽

10.5194/hess-11-647-2007 ◽

2007 ◽

Vol 11 (1) ◽

pp. 647-662 ◽

Cited By ~ 7

Author(s):

M. G. Hutchins ◽

C. Dilks ◽

H. N. Davies ◽

A. Deflandre

Keyword(s):

Input Data ◽

Model Performance ◽

Diffuse Pollution ◽

Model Complexity ◽

Data Sets ◽

Quality Model ◽

Performance Benchmarking ◽

North East ◽

Quantitative Performance ◽

Marginal Improvement

Abstract. Flow and nitrate dynamics were simulated in two catchments, the River Aire in northern England and the River Ythan in north-east Scotland. In the case of the Aire, a diffuse pollution model was coupled with a river quality model (CASCADE-QUESTOR); in the study of the Ythan, an integrated model (SWAT) was used. In each study, model performance was evaluated for differing levels of spatial representation in input data sets (rainfall, soils and land use). In respect of nitrate concentrations, the performance of the models was compared with that of a regression model based on proportions of land cover. The overall objective was to assess the merits of spatially distributed input data sets. In both catchments, specific measures of quantitative performance showed that models using the most detailed available input data contributed, at best, only a marginal improvement over simpler implementations. Hence, the level of complexity used in input data sets has to be determined, not only on multiple criteria of quantitative performance but also on qualitative assessments, reflecting the specific context of the model application and the current and likely future needs of end-users.

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Potential of Shallow Groundwater for Household Level Irrigation Practices in Tahtay Koraro Woreda, Tigray, Northern Ethiopia

Momona Ethiopian Journal of Science ◽

10.4314/mejs.v13i1.3 ◽

2021 ◽

Vol 13 (1) ◽

pp. 43-66

Author(s):

Ermias Hagos ◽

Amare Girmay ◽

Tesfamichael Gebreyohannes

Keyword(s):

Groundwater Recharge ◽

Large Scale ◽

Potential Evapotranspiration ◽

Shallow Groundwater ◽

Northern Ethiopia ◽

Groundwater Abstraction ◽

Groundwater Levels ◽

Household Level ◽

Average Value ◽

Dug Wells

This paper deals with the results of a pilot study conducted to estimate the shallow groundwater resource potential and irrigation capacity at the household level in Tahtay Koraro Woreda, northwestern zone of Tigray, Ethiopia. The potential evapotranspiration and actual evapotranspiration of the study area are estimated to be 1484 mm/year and 814 mm/year respectively. The runoff is approximately calculated to be 280 mm/year and the annual groundwater recharge is estimated to be 29 mm/year. The total annual groundwater abstraction for human, livestock, and irrigation is estimated to be 25 mm/year. It should be noted that the groundwater recharge rate is expected to remain constant while the total annual groundwater discharge is expected to increase from year to year. This relation when projected over a long period may result in a negative groundwater budget which can result in depletion of groundwater (lowering of groundwater levels), reduced baseflow to streams, and deterioration of water quality. The computed values for hydraulic conductivity of the aquifers range from 1.63 m/day to 7.27 m/day with an average value of 4.9 m/day and transmissivity from 48.9 m2/day to 218.1 m2/day with an average value of 147.14 m2/day. The aquifers in the highly weathered basalt and highly weathered siltstone – sandstone intercalation have transmissivity values ranging from 99 m2/day to 218.1 m2/day with an average value of 157 m2/day and are grouped into the moderate potentiality aquifers category. The aquifers in the slightly weathered and fractured metavolcanics grouped under low potentiality based on the lower transmissivity values (<50 m2/day). The study area has low to moderate groundwater potentiality, hence, large-scale groundwater pumping is not possible. Therefore, the current activity of using hand dug wells for household-level irrigation is the best way of using groundwater for irrigation and other uses as well. Increasing the depth of the existing hand dug wells that are constructed in highly weathered basalt and highly weathered siltstone – sandstone intercalation can also enhance the yield of the hand dug wells. It is recommended to use water-saving irrigation technologies rather than increasing the number of wells. This will also help in increasing the irrigation area. Groundwater recharge enhancement structures such as trenches, percolation ponds, and check dams be constructed in scientifically selected localities to further enhance the groundwater potential.

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Water Resources Observation and Large-scale Model Estimation in Forested Areas in Mekong River Basin

Japan Agricultural Research Quarterly JARQ ◽

10.6090/jarq.44.179 ◽

2010 ◽

Vol 44 (2) ◽

pp. 179-186 ◽

Cited By ~ 2

Author(s):

Akira SHIMIZU ◽

Masakazu SUZUKI ◽

Shinji SAWANO ◽

Naoki KABEYA ◽

Tatsuhiko NOBUHIRO ◽

...

Keyword(s):

Water Resources ◽

River Basin ◽

Large Scale ◽

Mekong River ◽

Scale Model ◽

Model Estimation ◽

Mekong River Basin ◽

Large Scale Model ◽

Forested Areas

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A multi-stage 3D stress field modelling approach exemplified in the Bavarian Molasse Basin

10.5194/se-2016-92 ◽

2016 ◽

Author(s):

Moritz O. Ziegler ◽

Oliver Heidbach ◽

John Reinecker ◽

Anna M. Przybycin ◽

Magdalena Scheck-Wenderoth

Keyword(s):

Stress State ◽

Input Data ◽

Large Scale ◽

Scattered Data ◽

In Situ Stress ◽

Scale Model ◽

Molasse Basin ◽

Multi Stage ◽

Subsurface Engineering

Abstract. The knowledge of the contemporary in-situ stress state is a key issue for a safe and sustainable subsurface engineering. However, information on the orientation and magnitudes of the stress state are few and often not available in the areas of interest. Therefore 3D geomechanical numerical modelling is used to estimate the in-situ stress state and the distance of faults from failure for application in subsurface engineering. The main challenge in this approach is to bridge the gap in scales between the widely scattered data used for calibration of the model and the high resolution in the target area required for the application. We present a multi-stage 3D geomechanical numerical approach which provides a state of the art model of the stress field for a reservoir scale area from widely scattered data records. Therefore we first use a large scale regional model which is calibrated by available stress data and provides the full 3D stress tensor at discrete points in the entire model volume. The modelled stress state is used subsequently for the calibration of a smaller scale model located within the large scale model in an area without any observed stress data records. We exemplify this approach with two-stages for the area around Munich in the German Molasse Basin. We estimate the scalar values for slip tendency and fracture potential as measures for the criticality of fault reactivation in the reservoir scale model. Furthermore, the modelling results show that variations due to uncertainties in the input data are mainly introduced by the uncertain material properties and missing SHmax magnitude data. This leads to the conclusion that at this stage the model’s reliability depends only on the amount and quality of available input data rather than on the modelling technique itself. Any improvements of modelling and increases in model reliability can only be achieved by more high-quality data for calibration.

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Improving continental scale hydrological model performance and stability under variable climate conditions in order to improve the assessment of future water resources

10.5194/egusphere-egu21-9284 ◽

2021 ◽

Author(s):

Wendy Sharples ◽

Andrew Frost ◽

Ulrike Bende-Michl ◽

Ashkan Shokri ◽

Louise Wilson ◽

...

Keyword(s):

Water Resources ◽

Water Balance ◽

Hydrological Model ◽

Model Performance ◽

Water Balance Components ◽

Climate Conditions ◽

Water Balance Component ◽

Multi Objective ◽

Model Parameterization ◽

The Future

Ensuring future water security in a changing climate is becoming a top priority for Australia, which is already dealing with the ongoing socio-economic and environmental impacts from record-breaking bushfires, infrastructure damage from recent flash flooding events, and the prospect of continuing compromised water sources in both regional towns and large cities into the future. In response to these significant impacts the Australian Bureau of Meteorology is providing a hydrological projections service, using their national operational hydrological model (The Australian Water Resources Assessment model: AWRA-L, www.bom.gov.au/water/landscape), to project future hydrological fluxes and states using downscaled meteorological inputs from an ensemble of curated global climate models and emissions scenarios at a resolution of 5km out to the end of this century.Continental model calibration using a long record of Australian observational data has been employed across components of the water balance, to tune the model parameters to Australia's varied hydro-climate, thereby reducing uncertainty associated with inputs and hydrological model structure. This approach has been shown to improve the accuracy of simulated hydrological fields, and the skill of short term and seasonal forecasts. However, in order to improve model performance and stability for use in hydrological projections, it is desirable to choose a model parameterization which produces reasonable hydrological responses under conditions of climate variability as well as under historical conditions. To this end we have developed a two-stage approach: Firstly, a variance based sensitivity analysis for water balance components (e.g. ephemeral flow, average to high flow, recharge, soil moisture and evapotranspiration) is performed, to rank the most influential parameters affecting water balance components. Parameters which are insensitive across components are then fixed to a previously optimized value, decreasing the number of calibratable parameters in order to decrease dimensionality and uncertainty in the calibration process. Secondly, a model configured with reduced calibratable parameters is put through a multi-objective evolutionary algorithm (Borg MOEA, www.borgmoea.org), to capture the tradeoffs between the water balance component performance objectives under climate variable conditions (e.g. wet, dry and historical) and across climate regions derived from the natural resource management model (https://nrmregionsaustralia.com.au/).The decreased dimensionality is shown to improve the stability and robustness of the existing calibration routine (shuffled complex evolution) as well as the multi-objective routine. Upon examination of the tradeoffs between the water balance component objective functions and in-situ validation data under historical, wet and dry periods and across different Australian climate regions, we show there is no one size fits all parameter set continentally, and thus some concessions need to be made in choosing a suitable model parameterization. However, future work could include developing a set of parameters which suit specific regions or climate conditions in Australia. The approach outlined in this study could be employed to improve confidence in any hydrological model used to simulate the future impacts of climate change.&#160;

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SWaBME: A PARSIMONIOUS LARGE-SCALE MODEL TO SIMULATE WATER BALANCE COMPONENTS OF TYPICAL LAND COVER TYPES IN BRAZIL

10.5194/egusphere-egu21-9298 ◽

2021 ◽

Author(s):

Marlus Sabino ◽

Rafael Rosolem ◽

Ross Woods ◽

Adilson Pacheco de Souza ◽

Humberto Ribeiro da Rocha ◽

...

Keyword(s):

Land Use ◽

Land Cover ◽

Water Balance ◽

Large Scale ◽

Mean Squared Error ◽

Scale Model ◽

Canopy Interception ◽

Water Balance Components ◽

Land Cover Types ◽

Parsimonious Model

Accurately identifying the interactions between large-scale land cover and regional climate in the water balance components is crucial for our understanding of how the transformation of native vegetation into agricultural areas impacts the water cycle. Yet the available regional models to access water balance components are often too complex and typically highly dependent on a large number of inputs and parameters. This inadvertently leads to relatively high uncertainty in the model components and their interactions, undermining their use for identifying controlling factor and mechanisms associated with key hydrological processes. In this work, we address the need for a parsimonious model by introducing the Soil Water Balance Modelling Environment (SWaBME). SWaBME is a novel parsimonious hydrological model used to assess the water balance partitioning of typical land cover types in Brazil, a country that is constantly affected by high rates of deforestation and agricultural expansion. The SWaBME model uses a Penman-Monteith formulation to estimate, separately and explicitly, the evapotranspiration (ET) in the three main components (bare soil evaporation, transpiration, and evaporation from canopy interception), which allow it to distinguish the effects of climate and land cover on the ET. The SWaBME model requires only five parameters to be prescribed a priori, and also contains a set of parameters which are directly provided by the recent development of global georeferenced data products. SWaBME is calibrated by following an alternative approach which evaluates hundreds of thousands of randomly generated parameter sets against observed monthly evapotranspiration and soil moisture data (when available) that are ultimately tested at a pre-defined set of soft rules to ensure model consistency. The model calibration were done individually at 10 flux sites in Brazil, &#160;but we also investigate whether such preferred parameter combinations produce plausible model performances at the country main land-cover and land-use classes: forests, cerrado/woodlands, pasture/grasslands, and soybean and sugarcane crops. From all the parameters combinations, the model was able to satisfactorily retain about 70 to 90% of the sets for forests and cropland biomes, but appears to constrain much more strongly for pasture/grasslands and cerrado biomes with respectively 30% and 1% of the set retained. Most of the introduced soft rules have low to moderate constraining power, and we found that differences in the calibrated parameters for each biome are more pronounced only when the prior information from literature review was used to constrain specific parameters ranges. The performance with the selected parameters showed Root Mean Squared Error of about 20 to 36 mm/month [RR1]&#160;at forest and cropland biomes, 23 to 26 mm/month at the cerrado/woodland and 30 to 36 mm/month at pasture/grasslands; ranking slight better when compared to the more complex (in terms of structure and number of parameters) NOAH/GLDAS model with a RMSE ranging from 30 to 60 mm/month. Overall, SWaBME is a parsimonious model aimed at large-scale application of water balance assessment focusing on assessing the impacts of climate and land-use/land-cover changes primarily in Brazil. However, the structure and approach used here can be widely transferred to other regions of the world.

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Water resources of the Desna river basin under future climate

Journal of Water and Climate Change ◽

10.2166/wcc.2021.034 ◽

2021 ◽

Author(s):

Osypov Valeriy ◽

Speka Oleh ◽

Chyhareva Anastasiia ◽

Osadcha Nataliia ◽

Krakovska Svitlana ◽

...

Keyword(s):

Water Resources ◽

River Basin ◽

General Circulation ◽

Large Scale ◽

Climate Models ◽

Assessment Tool ◽

General Circulation Models ◽

Future Climate ◽

Moderate Increase ◽

Water Balance Components

Abstract Climate change impact on water resources has been observing in Ukraine since the end of the 20th century. For now, only large-scale climate impact studies cover Ukraine territory, having low credibility for a specific catchment. This study aims to calculate future changes in river discharge, water flow components, and soil water within the Desna basin and evaluate vulnerability trends on this basis. The framework assembles the process-based SWAT (Soil and Water Assessment Tool) model and eight high-resolution regional climate models (RCMs) driven by RCP4.5 and RCP8.5 emission scenarios. The climate models are provided by the Euro-CORDEX initiative and based on three RCMs (RCA4, HIRHAM5, and RACMO22E) forced by five general circulation models (CNRM-CM5, EC-EARTH, IPSL-CM5A-MR, HadGEM2-ES, and MPI-ESM-LR). The results preferably show a moderate increase in the annual discharge till the end of the 21st century. The intra-annual changes of water balance components negatively affect the vegetation period because of higher dryness and temperature stress but reduce flood risk, diffuse pollution, and water erosion in the far future. In the river basin management plan, the highest attention should be paid to adaptive strategies in agriculture because of possible water deficit in the vegetation season under future climate scenarios.

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The influence of riverbank filtration on regional water resources: a case study in the Second Songhua River catchment, China

Water Science & Technology Water Supply ◽

10.2166/ws.2020.055 ◽

2020 ◽

Vol 20 (4) ◽

pp. 1425-1438

Author(s):

Xueyan Ye ◽

Ruijuan Cui ◽

Lixue Wang ◽

Xinqiang Du

Keyword(s):

Water Resources ◽

Groundwater Flow ◽

Large Scale ◽

River Flow ◽

Riverbank Filtration ◽

Groundwater Abstraction ◽

Songhua River ◽

Safe Yield ◽

Regional Water ◽

The Second Songhua River

Abstract Riverbank filtration (RBF) of river water recharging a groundwater system has been identified as a source of water supply that guarantees the quantity of abstracted water and reduces the cost of water treatment. This paper evaluates the safe yield of groundwater in suitable areas using a numerical model of groundwater flow and discusses the influence of RBF on the temporal variation of regional hydraulic heads, groundwater flow, river flow, and groundwater–surface water interaction (GSI) under different precipitation frequencies from 20% to 95% along the Second Songhua River in Northeast China. This study shows that the potential of RBF is enormous and that the total safe yield of groundwater abstraction was 29.56 × 104 m3/day under the precipitation frequency of 95%. The direction of regional groundwater flow was not obviously changed except within the local groundwater flow field under the maximum safe yield pumping conditions. When the precipitation frequencies are higher than 75%, the direction of the GSI might be changed, and the rate of river recharge of groundwater is enhanced. The water quantity that would be captured from the river does not threaten the safety of the river ecology. It is concluded that there were no obvious adverse impacts of the large scale of RBF on regional water resources in the Second Songhua River area.

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