Derivation of instantaneous unit hydrographs using linear reservoir models

In this research, a new conceptual model for producing instantaneous unit hydrographs (IUHs) is introduced by a linear combination of the Nash model, which assumes that the discharge from a reservoir is a linear function of its storage, and a model called inter-connected linear reservoir model (ICLR...

Full description

Bibliographic Details
Main Authors: Parjang Monajemi, Setareh Khaleghi, Shahrzad Maleki
Format: Article
Language:English
Published: IWA Publishing 2021-04-01
Series:Hydrology Research
Subjects:
Online Access:http://hr.iwaponline.com/content/52/2/339
_version_ 1818925560888295424
author Parjang Monajemi
Setareh Khaleghi
Shahrzad Maleki
author_facet Parjang Monajemi
Setareh Khaleghi
Shahrzad Maleki
author_sort Parjang Monajemi
collection DOAJ
description In this research, a new conceptual model for producing instantaneous unit hydrographs (IUHs) is introduced by a linear combination of the Nash model, which assumes that the discharge from a reservoir is a linear function of its storage, and a model called inter-connected linear reservoir model (ICLRM), which assumes that the discharge from a reservoir is a linear function of the difference of its storage and its adjacent downstream reservoir. By employing these assumptions, a system of first-order linear differential equations with three degrees of freedom (storage coefficient, number of reservoirs, and weighting coefficient) is obtained as the governing equation for the proposed model. This model may be considered as the general form of the two models and is therefore capable of simulating IUHs laying between these two models. To show the capabilities of the model, linear and curvilinear soil conservation service (SCS) hydrographs are simulated using dimensionless hydrographs obtained by this model. Moreover, several real hydrographs were simulated by the proposed model and compared with hydrographs obtained by Nash, ICLRM, and SCS models. The results show that the model yields more accurate results compared to other studied models and may be considered as a new model for simulating IUHs. HIGHLIGHTS Nash model and inter-connected linear reservoir model (ICLRM), being two extremes of linear reservoir models, are unified.; The general model is a linear combination of the Nash and ICLRM models.; The weighting coefficient gives the proposed model an extra degree of freedom.; This model yields more accurate results for the simulation of SCS hydrographs.;
first_indexed 2024-12-20T02:43:10Z
format Article
id doaj.art-f20d3a288863474a957cb7dc78312c52
institution Directory Open Access Journal
issn 1998-9563
2224-7955
language English
last_indexed 2024-12-20T02:43:10Z
publishDate 2021-04-01
publisher IWA Publishing
record_format Article
series Hydrology Research
spelling doaj.art-f20d3a288863474a957cb7dc78312c522022-12-21T19:56:15ZengIWA PublishingHydrology Research1998-95632224-79552021-04-0152233935510.2166/nh.2021.171171Derivation of instantaneous unit hydrographs using linear reservoir modelsParjang Monajemi0Setareh Khaleghi1Shahrzad Maleki2 Department of Civil Engineering, Faculty of Engineering, Fasa University, Fasa, Iran Department of Civil Engineering, Yasouj University, Yasouj, Iran Department of Civil Engineering, Faculty of Engineering, Fasa University, Fasa, Iran In this research, a new conceptual model for producing instantaneous unit hydrographs (IUHs) is introduced by a linear combination of the Nash model, which assumes that the discharge from a reservoir is a linear function of its storage, and a model called inter-connected linear reservoir model (ICLRM), which assumes that the discharge from a reservoir is a linear function of the difference of its storage and its adjacent downstream reservoir. By employing these assumptions, a system of first-order linear differential equations with three degrees of freedom (storage coefficient, number of reservoirs, and weighting coefficient) is obtained as the governing equation for the proposed model. This model may be considered as the general form of the two models and is therefore capable of simulating IUHs laying between these two models. To show the capabilities of the model, linear and curvilinear soil conservation service (SCS) hydrographs are simulated using dimensionless hydrographs obtained by this model. Moreover, several real hydrographs were simulated by the proposed model and compared with hydrographs obtained by Nash, ICLRM, and SCS models. The results show that the model yields more accurate results compared to other studied models and may be considered as a new model for simulating IUHs. HIGHLIGHTS Nash model and inter-connected linear reservoir model (ICLRM), being two extremes of linear reservoir models, are unified.; The general model is a linear combination of the Nash and ICLRM models.; The weighting coefficient gives the proposed model an extra degree of freedom.; This model yields more accurate results for the simulation of SCS hydrographs.;http://hr.iwaponline.com/content/52/2/339instantaneous unit hydrographlinear reservoir modelnash modelsystem of linear first-order differential equations
spellingShingle Parjang Monajemi
Setareh Khaleghi
Shahrzad Maleki
Derivation of instantaneous unit hydrographs using linear reservoir models
Hydrology Research
instantaneous unit hydrograph
linear reservoir model
nash model
system of linear first-order differential equations
title Derivation of instantaneous unit hydrographs using linear reservoir models
title_full Derivation of instantaneous unit hydrographs using linear reservoir models
title_fullStr Derivation of instantaneous unit hydrographs using linear reservoir models
title_full_unstemmed Derivation of instantaneous unit hydrographs using linear reservoir models
title_short Derivation of instantaneous unit hydrographs using linear reservoir models
title_sort derivation of instantaneous unit hydrographs using linear reservoir models
topic instantaneous unit hydrograph
linear reservoir model
nash model
system of linear first-order differential equations
url http://hr.iwaponline.com/content/52/2/339
work_keys_str_mv AT parjangmonajemi derivationofinstantaneousunithydrographsusinglinearreservoirmodels
AT setarehkhaleghi derivationofinstantaneousunithydrographsusinglinearreservoirmodels
AT shahrzadmaleki derivationofinstantaneousunithydrographsusinglinearreservoirmodels