scholarly journals Is the groundwater reservoir linear? Learning from data in hydrological modelling

2005 ◽  
Vol 2 (4) ◽  
pp. 1717-1755 ◽  
Author(s):  
F. Fenicia ◽  
H. H. G. Savenije ◽  
P. Matgen ◽  
L. Pfister
Keyword(s):  
A Priori ◽  
Model Performance ◽  
Flow Simulation ◽  
Calibration Procedure ◽  
Low Flow ◽  
Low Flows ◽  
Learning From Data ◽  
Recession Curve ◽  
Master Recession Curve ◽  
High Flows

Abstract. Although catchment behaviour during recession periods appears to be better identifiable than in other periods, the representation of hydrograph recession is often weak in hydrological simulations. Reason lies in the various sources of uncertainty that affect hydrological simulations, and in particular in the inherent uncertainty concerning model conceptualizations, when they are based on an a-priori representation of the natural system. When flawed conceptualizations combine with calibration strategies that favour an accurate representation of peak flows, model structural inadequacies manifest themselves in a biased representation of other aspects of the simulation, such as flow recession and low flows. In this paper we try to reach good model performance in low flow simulation and make use of a flexible model structure that can adapt to match the observed discharge behaviour during recession periods. Moreover, we adopt a step-wise calibration procedure where we try to avoid that the simulation of low flows is neglected in favour of other hydrograph characteristics. The model used is designed to reproduce specific hydrograph characteristics and is composed of four reservoirs: an interception reservoir, an unsaturated soil reservoir, a fast reacting reservoir, and a slow reacting reservoir. The slow reacting reservoir conceptualises the processes that lead to the generation of the slow hydrograph component, and is characterized by a storage-discharge relation that is not determined a-priori, but is derived from the observations following a ``top-down'' approach. The procedure used to determine this relation starts by calculating a synthetic master recession curve that represents the long-term recession of the catchment. Next, a calibration procedure follows to force the outflow from the slow reacting reservoir to match the master recession curve. Low flows and high flows related parameters are calibrated in separate stages because we consider them to be related to different processes, which can be identified separately. This way we avoid that the simulation of low discharges is neglected in favour of a higher performance in simulating peak discharges. We have applied this analysis to several catchments in Luxembourg, and in each case we have determined which form (linear or non linear) of the storage-discharge relationship best describes the slow reacting reservoir. We conclude that in all catchments except one (where human interference is high) a linear relation applies.

Exploring natural and induced drivers in the Magdalena River discharge impacting the Ciénaga Grande de Santa Marta coastal-lagoon ecosystem

2021 ◽  
Author(s):  
Santiago Gómez-Dueñas ◽  
Allen Bateman ◽  
Germán Santos ◽  
Raúl Sosa
Keyword(s):  
Coastal Lagoon ◽  
Southern Oscillation ◽  
A Priori ◽  
Open Water ◽  
Low Flow ◽  
Enso Events ◽  
Low Flows ◽  
Rain Season ◽  
Discharge Regime ◽  
High Flows

<p>Magdalena's river basin represents a quarter of Colombia's surface, yet neighbouring ecosystems remain ignored while enduring unacceptable environmental conditions. At its outlet in the Caribbean Sea, several channels link it to Cienaga Grande de Santa Marta (CGSM), a deltaic coastal-lagoon ecosystem (4200 km<sup>2</sup>) from which around 15 to 20 % are water bodies. According to several studies, Magdalena River's overflows represent its primary freshwater source. However, the recorded discharge has gradually reduced, though the basin's rainfall shows a rising tendency. Additional discharge measurements close to the outlet evidenced that it was even lesser than records upstream counterintuitively. Consequently, the energy gradient from the river to the sea through the ecosystem is reversing more frequently. That has resulted in a continuous salinisation process of the lagoons, diminishment of the mangrove forest and lagoons extension, fauna migration and low water quality. This research aims to elaborate on the Magdalena River's outlet discharges vulnerabilities in Colombia, thus providing better insight into impact-based decision-making. </p><p>Results suggest that the discharge regime responds to the El Niño Southern Oscillation (ENSO) phenomenon as it controls the country's dry/rain season. Further analysis indicates that a) low flows relate to El Niño periods and high flows to La Niña; b) the flow duration curve's slope is getting milder, meaning that high flows are decreasing whereas low flows are increasing; c) extreme discharges are getting smoother, and less disperse so that high and low flow peaks are within a smaller range; d) the dispersion diminishes radically during severe El Niño events, and e) although a priori the assumption is that the more severe El Niño events might bring lower discharge values, the minimum values recorded are more significant than in neutral ENSO conditions. </p><p>Moreover, extreme discharge values during ENSO events, despite their severity, tended to have a horizontal asymptote that suggests human-driven control upstream, especially during El Niño periods. The Magdalena basin holds Colombia's hydropower network representing more than 70% of its electricity supply distributed in 33 operating plants. On the one hand, it is clear that during El Niño, the plants guarantee a minimum discharge downstream, as it is when the National Hydrometeorological Agency only considers drought protocols. However, during neutral ENSO conditions, the flows are not controlled and thus, impacts downstream arise. On the other hand, reservoirs have increased evaporation due to a large accumulated open water surface (611 km<sup>2</sup> in total). Results show that water loss represents 40% to 80% of the current average discharge at the outlet (7000 m<sup>3</sup>/s), adding to the ecosystem depletion. The results urge decision-makers to reconsider the drought protocols applying an impact-based approach.</p>

scholarly journals Is the groundwater reservoir linear? Learning from data in hydrological modelling

2006 ◽  
Vol 10 (1) ◽  
pp. 139-150 ◽  
Author(s):  
F. Fenicia ◽  
H. H. G. Savenije ◽  
P. Matgen ◽  
L. Pfister
Keyword(s):  
Iterative Process ◽  
A Priori ◽  
Model Performance ◽  
Calibration Procedure ◽  
Hydrological Modelling ◽  
Suitable Model ◽  
Discharge Data ◽  
Low Flows ◽  
Groundwater Reservoir ◽  
Linear Reservoir

Abstract. Although catchment behaviour during recession periods is better identifiable than in other periods, the representation of hydrograph recession is often weak in hydrological simulations. Among the various aspects that influence model performance during low flows, in this paper we concentrate on those more inherently related to the modelling, such as the development of a suitable model conceptualization, and the choice of an appropriate calibration strategy. In this context we develop a methodology where the calibration procedure is combined with an iterative process of model improvement, to obtain an optimal model configuration that performs well both during low flows and high flows. The methodology starts by calculating a synthetic master recession curve that represents the long-term recession of a given catchment. Subsequently, using a simple reservoir model, we determine the storage-discharge relation that simulates the slow hydrograph component. This relation is determined without making any a-priori assumption on its form and is inferred from discharge data available through an iterative process. Next, high flow related parameters are recalibrated separately, to avoid that the simulation of low discharges is neglected in favour of a higher performance in simulating peak discharges. This methodology is applied on several catchments in Luxembourg, and as a result we determined that in all catchments except one (where human interference is high) within the chosen model structure a linear reservoir describes best the observed groundwater behaviour. This result is used to trigger a discussion as to the general suitability of the use of a linear groundwater reservoir in hydrological modelling.

scholarly journals Contrasting Differences in Responses of Streamflow Regimes between Reforestation and Fruit Tree Planting in a Subtropical Watershed of China

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 212 ◽  
Author(s):  
Zhipeng Xu ◽  
Wenfei Liu ◽  
Xiaohua Wei ◽  
Houbao Fan ◽  
Yizao Ge ◽  
...  
Keyword(s):  
Flow Regime ◽  
Fruit Tree ◽  
High Flow ◽  
Tree Planting ◽  
Low Flow ◽  
Jiangxi Province ◽  
Negative Effects ◽  
Flow Duration ◽  
Low Flows ◽  
High Flows

Fruit tree planting is a common practice for alleviating poverty and restoring degraded environment in developing countries. Yet, its environmental effects are rarely assessed. The Jiujushui watershed (261.4 km2), located in the subtropical Jiangxi Province of China, was selected to assess responses of several flow regime components on both reforestation and fruit tree planting. Three periods of forest changes, including a reference (1961 to 1985), reforestation (1986 to 2000) and fruit tree planting (2001 to 2016) were identified for assessment. Results suggest that the reforestation significantly decreased the average magnitude of high flow by 8.78%, and shortened high flow duration by 2.2 days compared with the reference. In contrast, fruit tree planting significantly increased the average magnitude of high flow by 27.43%. For low flows, reforestation significantly increased the average magnitude by 46.38%, and shortened low flow duration by 8.8 days, while the fruit tree planting had no significant impact on any flow regime components of low flows. We conclude that reforestation had positive impacts on high and low flows, while to our surprise, fruit tree planting had negative effects on high flows, suggesting that large areas of fruit tree planting may potentially become an important driver for some negative hydrological effects in our study area.

scholarly journals A large sample analysis of European rivers on seasonal river flow correlation and its physical drivers

2019 ◽  
Vol 23 (1) ◽  
pp. 73-91 ◽  
Author(s):  
Theano Iliopoulou ◽  
Cristina Aguilar ◽  
Berit Arheimer ◽  
María Bermúdez ◽  
Nejc Bezak ◽  
...  
Keyword(s):  
River Flow ◽  
Frequency Estimation ◽  
Low Flow ◽  
Time Lags ◽  
Low Flows ◽  
Flow Formation ◽  
Gaussian Probability Distribution ◽  
High Flows ◽  
Seasonal Correlation ◽  
Seasonal Streamflow

Abstract. The geophysical and hydrological processes governing river flow formation exhibit persistence at several timescales, which may manifest itself with the presence of positive seasonal correlation of streamflow at several different time lags. We investigate here how persistence propagates along subsequent seasons and affects low and high flows. We define the high-flow season (HFS) and the low-flow season (LFS) as the 3-month and the 1-month periods which usually exhibit the higher and lower river flows, respectively. A dataset of 224 rivers from six European countries spanning more than 50 years of daily flow data is exploited. We compute the lagged seasonal correlation between selected river flow signatures, in HFS and LFS, and the average river flow in the antecedent months. Signatures are peak and average river flow for HFS and LFS, respectively. We investigate the links between seasonal streamflow correlation and various physiographic catchment characteristics and hydro-climatic properties. We find persistence to be more intense for LFS signatures than HFS. To exploit the seasonal correlation in the frequency estimation of high and low flows, we fit a bi-variate meta-Gaussian probability distribution to the selected flow signatures and average flow in the antecedent months in order to condition the distribution of high and low flows in the HFS and LFS, respectively, upon river flow observations in the previous months. The benefit of the suggested methodology is demonstrated by updating the frequency distribution of high and low flows one season in advance in a real-world case. Our findings suggest that there is a traceable physical basis for river memory which, in turn, can be statistically assimilated into high- and low-flow frequency estimation to reduce uncertainty and improve predictions for technical purposes.

scholarly journals Topography significantly influencing low flows in snow-dominated watersheds

2017 ◽  
Author(s):  
Qiang Li ◽  
Xiaohua Wei ◽  
Xin Yang ◽  
Krysta Giles-Hansen ◽  
Mingfang Zhang ◽  
...  
Keyword(s):  
Regression Models ◽  
Low Flow ◽  
Mean Flow ◽  
Slope Length ◽  
Low Flows ◽  
Slope Length Factor ◽  
High Flows ◽  
Flow Variables ◽  
Characterization Index

Abstract. Watershed topography plays an important role in determining the spatial heterogeneity of ecological, geomorphological, and hydrological processes. Few studies have quantified the role of topography on various flow variables. In this study, 28 watersheds with snow-dominated hydrological regimes were selected with daily flow records from 1989 to 1996. The watersheds are located in the Southern Interior of British Columbia, Canada and range in size from 2.6 to 1,780 km2. For each watershed, 22 topographic indices (TIs) were derived, including those commonly used in hydrology and other environmental fields. Flow variables include annual mean flow (Qmean), Q10%, Q25%, Q50%, Q75%, Q90%, and annual minimum flow (Qmin), where Qx% is defined as flows that at the percentage (x) occurred in any given year. Factor analysis (FA) was first adopted to exclude some redundant or repetitive TIs. Then, stepwise regression models were employed to quantify the relative contributions of TIs to each flow variable in each year. Our results show that topography plays a more important role in low flows than high flows. However, the effects of TIs on flow variables are not consistent. Our analysis also determines five significant TIs including perimeter, surface area, openness, terrain characterization index, and slope length factor, which can be used to compare watersheds when low flow assessments are conducted, especially in snow-dominated regions.

scholarly journals Comparing Trends in Modeled and Observed Streamflows at Minimally Altered Basins in the United States

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1728
Author(s):  
Glenn A. Hodgkins ◽  
Robert W. Dudley ◽  
Amy M. Russell ◽  
Jacob H. LaFontaine
Keyword(s):  
United States ◽  
Model Performance ◽  
The United States ◽  
Model Fit ◽  
Distributed Parameter ◽  
Mean Flow ◽  
Low Flows ◽  
High Flows ◽  
Found Model ◽  
Transfer Models

We compared modeled and observed streamflow trends from 1984 to 2016 using five statistical transfer models and one deterministic, distributed-parameter, process-based model, for 26 flow metrics at 502 basins in the United States that are minimally influenced by development. We also looked at a measure of overall model fit and average bias. A higher percentage of basins, for all models, had relatively low trend differences between modeled and observed mean/median flows than for very high or low flows such as the annual 1-day high and 7-day low flows. Mean-flow metrics also had the largest percentage of basins with relatively good overall model fit and low bias. The five statistical transfer models performed better at more basins than the process-based model. The overall model fit for all models, for mean and/or high flows, was correlated with one or more measures of basin precipitation or aridity. Our study and previous studies generally observed good model performance for high flows up to 90th or 95th percentile flows. However, we found model performance was substantially worse for more extreme flows, including 99th percentile and annual 1-day high flows, indicating the importance of including more extreme high flows in analyses of model performance.

scholarly journals Benchmarking hydrological models for low-flow simulation and forecasting on French catchments

2013 ◽  
Vol 10 (11) ◽  
pp. 13979-14040 ◽  
Author(s):  
P. Nicolle ◽  
R. Pushpalatha ◽  
C. Perrin ◽  
D. François ◽  
D. Thiéry ◽  
...  
Keyword(s):  
Prediction Models ◽  
Model Performance ◽  
Flow Simulation ◽  
Evaluation Framework ◽  
Low Flow ◽  
Lead Times ◽  
Hydrological Models ◽  
Model Efficiency ◽  
Different Characteristics ◽  
Better Than

Abstract. Low-flow simulation and forecasting remains a difficult issue for hydrological modellers, and intercomparisons are needed to assess existing low-flow prediction models and to develop more efficient operational tools. This study presents the results of a collaborative experiment conducted to compare low-flow simulation and forecasting models on 21 unregulated catchments in France. Five hydrological models with different characteristics and conceptualizations were applied following a common evaluation framework and assessed using a common set of criteria. Two simple benchmarks were used to set minimum levels of acceptability for model performance in simulation and forecasting modes. Results showed that, in simulation as well as in forecasting modes, all hydrological models performed almost systematically better than the benchmarks. Although no single model outperformed all the others in all circumstances, a few models appeared more satisfactory than the others on average. In simulation mode, all attempts to relate model efficiency to catchment characteristics remained inconclusive. In forecasting mode, we defined maximum useful forecasting lead times beyond which the model does not contribute useful information compared to the benchmark. This maximum useful lead time logically varies between catchments, but also depends on the model used. Preliminary attempts to implement simple multi-model approaches showed that additional efficiency gains can be expected from such approaches.

scholarly journals An application of the HBV model to the Tamor Basin in Eastern Nepal

1970 ◽  
Vol 7 (1) ◽  
pp. 49-58 ◽  
Author(s):  
S Normand ◽  
M Konz ◽  
J Merz
Keyword(s):  
Monsoon Season ◽  
Model Performance ◽  
Discharge Data ◽  
Ice Melt ◽  
Low Flows ◽  
High Flows ◽  
Hbv Model ◽  
Gauged Basins ◽  
Two Parameter ◽  
Precipitation Events

The semi-distributed, conceptual hydrological model HBV was applied to Tamor Nadi in order to estimate runoff at Tapethok, Taplejung, in Eastern Nepal. As there was no discharge data available for this particular location, the model was first calibrated and validated for the bigger, gauged basins at Mulghat and Majithar. However due to its structure HBV shows difficulties in modelling low and high flows correctly at the same time. Therefore two parameter sets were produced: one with focus on the model performance during low flows and the second one, on high flows. Those parameters were then applied to the basin at Tapethok. Generally HBV was able to correctly simulate low flows except for some sharp peaks due to isolated precipitation events. However, pre-monsoon discharge was overestimated while the runoff of the monsoon season were most of the time underestimated. The main reasons for this situation are: (1) HBV generates runoff from one single groundwater reservoir for the entire catchment, leading to sharp peaks with a rapid recession and therefore exaggerated reactions on precipitation during dry season; (2) during pre-monsoon snow and ice melt gain in importance and add to the mentioned problem; (3) due to the simplified representation of storages in the model structure the catchment area drains too quickly. Keywords: Tamor BasinDOI: http://dx.doi.org/10.3126/jhm.v7i1.5616  JHM 2010; 7(1): 49-58 

Identifying a Suitable Model for Low-Flow Simulation in Watersheds of South-Central Chile: A Study Based on a Sensitivity Analysis

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1506 ◽  
Author(s):  
Víctor Parra ◽  
Jose Luis Arumí ◽  
Enrique Muñoz
Keyword(s):  
Sensitivity Analysis ◽  
Flow Simulation ◽  
Low Flow ◽  
Suitable Model ◽  
Groundwater Storage ◽  
Release Process ◽  
Central Chile ◽  
Low Flows ◽  
South Central ◽  
Steep Topography

Choosing a model that suitably represents the characteristics of a watershed to simulate low flows is crucial, especially in watersheds whose main source of baseflow generation depends on groundwater storage and release. The goal of this investigation is to study the performance and representativeness of storage-release process modeling, considering aspects such as the topography and geology of the modeled watershed through regional sensitivity analysis, in order to improve low-flow prediction. To this end, four groundwater storage-release structures in various watersheds with different geological (fractured and sedimentary rock) and topographic domains (steep and gentle slopes) were analyzed. The results suggest that the two-reservoir structure with three runoff responses is suitable (better) for simulating low flows in watersheds with fractured geological characteristics and rugged or steep topography. The results also indicate that a one-reservoir model can be adequate for predicting low flows in watersheds with a sedimentary influence or flat topography.

scholarly journals Comparison of hydrological model structures based on recession and low flow simulations

2011 ◽  
Vol 8 (4) ◽  
pp. 6833-6866 ◽  
Author(s):  
M. Staudinger ◽  
K. Stahl ◽  
J. Seibert ◽  
M. P. Clark ◽  
L. M. Tallaksen
Keyword(s):  
Hydrological Model ◽  
Lower Layer ◽  
Model Performance ◽  
Low Flow ◽  
Model Structure ◽  
Hydrological Models ◽  
Flow Simulations ◽  
Low Flows ◽  
The Impact ◽  
Model Structures

Abstract. Low flows are often poorly reproduced by commonly used hydrological models, which are traditionally designed to meet peak flow situations. Hence, there is a need to improve hydrological models for low flow prediction. This study assessed the impact of model structure on low flow simulations and recession behaviour using the Framework for Understanding Structural Errors (FUSE). FUSE identifies the set of subjective decisions made when building a hydrological model, and provides multiple options for each modeling decision. Altogether 79 models were created and applied to simulate stream flows in the snow dominated headwater catchment Narsjø in Norway (119 km2). All models were calibrated using an automatic optimisation method. The results showed that simulations of summer low flows were poorer than simulations of winter low flows, reflecting the importance of different hydrological processes. The model structure influencing winter low flow simulations is the lower layer architecture, whereas various model structures were identified to influence model performance during summer.

Sign in / Sign up

Export Citation Format

Share Document