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 Characterization of the Groundwater Storage Systems of South-Central Chile: An Approach Based on Recession Flow Analysis

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2324
Author(s):  
Víctor Parra ◽  
José Luis Arumí ◽  
Enrique Muñoz ◽  
Jerónimo Paredes
Keyword(s):  
Storage Systems ◽  
Flow Analysis ◽  
Groundwater Storage ◽  
Release Process ◽  
Central Chile ◽  
Minimum Flow ◽  
Geological Characteristics ◽  
South Central ◽  
Flow Generation

Groundwater storage and discharge are important processes that have not yet been sufficiently studied in some parts of Chile. Additionally, in watersheds without snow cover or glaciers, groundwater storage and release are the main sources of minimum flow generation; therefore, improvements are required to characterize this process. This study aimed to use recession flow analysis to link groundwater storage depletion to the predominant geological characteristics of each watershed in order to improve our understanding of the groundwater storage-release process in 24 watersheds in south-central Chile. The results allowed different groundwater storage behaviors associated with different geological characteristics to be identified, making recession flow analysis a valuable tool for improving the representation and conceptualization of this process in order to advance toward better minimum flow predictions.

A downward structural sensitivity analysis of hydrological models to improve low-flow simulation

2011 ◽  
Vol 411 (1-2) ◽  
pp. 66-76 ◽  
Author(s):  
Raji Pushpalatha ◽  
Charles Perrin ◽  
Nicolas Le Moine ◽  
Thibault Mathevet ◽  
Vazken Andréassian
Keyword(s):  
Sensitivity Analysis ◽  
Flow Simulation ◽  
Low Flow ◽  
Hydrological Models ◽  
Structural Sensitivity ◽  
Structural Sensitivity Analysis

scholarly journals Comparison of Three Daily Rainfall-Runoff Hydrological Models Using Four Evapotranspiration Models in Four Small Forested Watersheds with Different Land Cover in South-Central Chile

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3191
Author(s):  
Neftali Flores ◽  
Rolando Rodríguez ◽  
Santiago Yépez ◽  
Victor Osores ◽  
Pedro Rau ◽  
...  
Keyword(s):  
Flow Simulation ◽  
Daily Rainfall ◽  
Hydrological Models ◽  
Rainfall Runoff ◽  
Hydrologic Models ◽  
Central Chile ◽  
South Central ◽  
Robust Model ◽  
Sensitive Parameters

We used the lumped rainfall–runoff hydrologic models Génie Rural à 4, 5, 6 paramètres Journalier (GR4J, GR5J and GR6J) to evaluate the most robust model for simulating discharge on four forested small catchments (<40 ha) in south-central Chile. Different evapotranspiration methods were evaluated: Oudin, Hargreaves–Samani and Priestley–Taylor. Oudin’s model allows the achievement of the highest efficiencies in the flow simulation. The more sensitive parameters for each model were identified through a Generalized Probability Uncertainty Estimation (GLUE) model. Our results demonstrate that the three hydrological models were capable of efficiently simulating flow in the four study catchments. However, the GR6J model obtained the most satisfactory results in terms of simulated to measured streamflow closeness. In general, the three models tended to underestimate peak flow, as well as underestimate and overestimate flow events in most of the in situ observations, according to the probability of non-exceedance. We also evaluated the models’ performance in a simulation of summer discharge due to the importance of downstream water supply in the months of greatest scarcity. Again, we found that GR6J obtained the most efficient simulations.

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.

scholarly journals Constraining a lumped rainfall-runoff model with piezometry to improve low-flow simulation

2021 ◽  
Author(s):  
Antoine Pelletier ◽  
Vakzen Andréassian
Keyword(s):  
Flow Simulation ◽  
Daily Rainfall ◽  
Climatic Conditions ◽  
Low Flow ◽  
Hydrological Models ◽  
Rainfall Runoff ◽  
Low Flows ◽  
Sample Test ◽  
Rainfall Runoff Model ◽  
Runoff Model

&lt;p&gt;Most lumped hydrological models are focused on the rainfall-runoff relationship, since climatic conditions are the driving force of the hydrological behaviour of a catchment. Many hydrological models, like the ones used by the French national PREMHYCE platform, only take climatic variables as inputs &amp;#8211; daily rainfall and potential evaporation &amp;#8211; to simulate and forecast low-flows. Yet, a hydrological drought is generally a medium- to long-term phenomenon, which is the consequence of long records of dry climatic conditions. Daily lumped hydrological models often struggle to integrate these records to reproduce catchment memory.&lt;/p&gt;&lt;p&gt;In many French catchments, it was observed that this memory of past hydroclimatic conditions is well represented in piezometric signals that are broadly available over the national territory. Indeed, aquifers, especially the large ones, do store water on the long, feeding rivers during droughts: aquifers are not only &lt;em&gt;water carriers&lt;/em&gt; &amp;#8211; the etymology for the word &lt;em&gt;aquifer &lt;/em&gt;&amp;#8211; they are also &lt;em&gt;memory carriers&lt;/em&gt;. A dataset of 108 catchments, each of them being associated with one or several piezometers, was used to investigate whether the GR6J daily lumped rainfall-runoff model could be constrained by piezometric time series to improve low-flow simulations. We found that a particular state of the model, the exponential store, is particularly well correlated with piezometry in most studied catchments.&lt;/p&gt;&lt;p&gt;In order to get a univocal relationship between the exponential store and piezometry, a multi-objective calibration approach was implemented, optimising both (i) flow simulation with a criterion focused on low-flows and (ii) affine correspondence between the exponential store level and piezometry. For that purpose, a new parameter was added to the model. The modified calibration was then evaluated through a split-sample test and the performance in simulating particular drought events. The calibrated store-piezometry relationship can now be used for data assimilation to improve low-flow forecasting.&lt;/p&gt;

scholarly journals Cardiorespiratory Fitness: Reference on the Six-Minute Walk Test and Oxygen Consumption in Adolescents from South-Central Chile

2021 ◽  
Vol 18 (5) ◽  
pp. 2474
Author(s):  
Jaime Vásquez-Gómez ◽  
Nelson Gatica Salas ◽  
Pedro Jiménez Villarroel ◽  
Luis Rojas-Araya ◽  
Cesar Faundez-Casanova ◽  
...  
Keyword(s):  
Cardiorespiratory Fitness ◽  
Reference Values ◽  
Estimation Error ◽  
Walk Test ◽  
Central Chile ◽  
Six Minute Walk Test ◽  
Body Adiposity ◽  
South Central ◽  
Males And Females ◽  
Minute Walk

Cardiorespiratory fitness (CRF) provides oxygen to the exercising muscles and is related to body adiposity, with cardiometabolic variables. The aim was to develop reference values and a predictive model of CRF in Chilean adolescents. A total of 741 adolescents of both genders (15.7 years old) participated in a basic anthropometry, performance in the six-minute walk test (SMWT), and in Course Navette was measured. Percentiles were determined for the SMWT, for the V̇O2max, and an equation was developed to estimate it. The validity of the equation was checked using distribution assumptions and the Bland–Altman diagram. The STATA v.14 program was used (p < 0.05). The 50th percentile values for males and females in the SMWT and in the V̇O2max of Course Navette were, respectively, from 607 to 690 and from 630 to 641 m, and from 43.9 to 45 and from 37.5 to 31.5 mlO2·kg·min−1, for the range of 13 to 17 years. For its part, the model to predict V̇O2max incorporated gender, heart rate, height, waist-to-height ratio (WHR), and distance in the SMWT (R2 = 0.62; estimation error = 0.38 LO2·min−1; p <0.001). Reference values can guide physical fitness in Chilean adolescents, and V̇O2max was possible to predict from morphofunctional variables.

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