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Lily Montarcih Limantara - One of the best experts on this subject based on the ideXlab platform.
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Conformity evaluation of synthetic Unit Hydrograph (case study at upstream Brantas sub watershed, East Java Province of Indonesia)
Journal of Water and Land Development, 2017Co-Authors: Dwi Priyantoro, Lily Montarcih LimantaraAbstract:AbstractThis study intends to analyse the suitable Hydrograph in upstream Brantas sub watershed. The methodology consists of comparing the result of Hydrograph due to the methods of Nakayasu synthetic Unit Hydrograph (SUH), Limantara synthetic Unit Hydrograph, and the observed Unit Hydrograph. In detail, this study intends to know the difference of Hydrograph parameters: α and Tg as recommended by Nakayasu and in the study location; to know the influence of main river length which is used in the methods of Nakayasu and Limantara to the time of concentration; to know the Hydrograph ordinate deviation between Nakayasu and Limantara due to the observed Hydrograph. Result is hoped for recommending the suitable Hydrograph in upstream Brantas subwatershed so that it can be used accurately for the further design of water resources structure.
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suitable synthetic Unit Hydrograph at rungun hulu sub watershed centre kalimantan of indonesia
2012Co-Authors: Lily Montarcih LimantaraAbstract:Synthetic Unit Hydrograph (SUH) could become the source of some important information that was necessary for reliable hydraulic structures and planning. Among stakeholders, the application of the models was meant for analyzing design floods through the uses of rainfall data input. Ideally, every watershed had its own specific Unit Hydrograph. The aim of this study was to compare two kinds SUH application of Nakayasu and Limantara. This study conducted at Rungun Hulu Sub-Watershed in Centre Kalimantan of Indonesia. In order to produce the suitable models, method was based on calibration parameter of each model due to observed Unit Hydrograph. The results suggested the suitable physical parameter of each model for applying in location study. In further development, the results intended to find out the nature of watershed responses against precipitation data input, where by it could become the supportive warning system to area that were vulnerable to flooding and resumed up Hydrograph data availability that were previously vacant due to operational problem of the Automatic Water Level Recorder (AWLR)
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The Limiting Physical Parameters of Synthetic Unit Hydrograph
World applied sciences journal, 2009Co-Authors: Lily Montarcih LimantaraAbstract:This paper studied Synthetic Unit Hydrograph Model. The methodology consisted of analysis of observed Unit Hydrograph and the primary physical parameters of watershed. Results revealed that length of river and area of watershed were the primary physical parameters. Further research is needed focusing on roughness coefficient of the river.
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evaluation of roughness constant of river in synthetic Unit Hydrograph
2009Co-Authors: Lily Montarcih LimantaraAbstract:This paper studied the effect of roughness coefficient in Synthetic Unit Hydrograph (SUH). The methodology consisted of formulation of peak discharge, rising curve and recession equation. Results showed that there are forests and some dry fileds, rice fields, real estate etc in the watershed. Forest with many big trees will produce high roughness coefficient, because there are not many rains become to be run off.
M M A Shahin - One of the best experts on this subject based on the ideXlab platform.
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regional analysis using the geomorphoclimatic instantaneous Unit Hydrograph
Hydrology and Earth System Sciences, 2001Co-Authors: M J Hall, A F Zaki, M M A ShahinAbstract:Abstract. The construction of design flood Hydrographs for ungauged drainage areas has traditionally been approached by regionalisation, i.e. the transfer of information from the gauged to the ungauged catchments in a region. Such approaches invariably depend upon the use of multiple linear regression analysis to relate Unit Hydrograph parameters to catchment characteristics and generalised rainfall statistics. The concept of the geomorphological instantaneous Unit Hydrograph (GIUH), in relating the shape and scale of the catchment transfer function to stream network topology and channel characteristics, offers an alternative methodology. GIUH derivation depends upon a series of assumptions, including that of estimating a "characteristic velocity"; these continue to attract attention and debate. However, if this velocity is expressed in terms of the kinematic wave approximation, the peak and time-to-peak of the IUH may be expressed in terms of a group of catchment and channel characteristics and the intensity of rainfall excess, giving the so-called geomorphoclimatic IUH (GCIUH). Previous studies involving the GCIUH have developed a single IUH relating to the total duration of rainfall excess. In this study, the rainfall excess duration was divided into several (equal) time increments, with separate IUHs being generated for each interval. This quasi-linear approach was applied to 105 storm events from nine catchments in the south-west of England, ranging in size from 6 to 420 (km)2 . The results showed that, providing the time interval chosen is fine enough to capture the shape of the runoff Hydrographs, a comparable level of goodness-of-fit can be obtained for catchments covering a range of about 1:75 in area. The modified GCIUH approach as described is therefore recommended for further investigation and intercomparison with regression-based regionalisation methods. Keywords: floods; geomorphology; rainfall-runoff modelling
Faustino N Gimena - One of the best experts on this subject based on the ideXlab platform.
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application of a Unit Hydrograph based on subwatershed division and comparison with nash s instantaneous Unit Hydrograph
Catena, 2005Co-Authors: U Agirre, Mikel Goni, Jose Javier Azanza Lopez, Faustino N GimenaAbstract:Abstract The Unit Hydrograph (UH) technique is widely used for runoff estimation, especially for determining peak discharges. In this paper, a geomorphologically based UH has been applied. Its most remarkable characteristic is that it includes the watershed structure in its formulation. This is defined from the drainage network, each subwatershed being considered as a linear reservoir. In this method, the fact of considering this reservoir sequence according to the drainage network leads to the formulation of the model only depending on a single parameter. The Geomorphological Unit Hydrograph of Reservoirs (GUHR), proposed in this paper, is compared with Nash's Instantaneous Unit Hydrograph (Nash's IUH), by applying the two methods to the Aixola watershed. This 4.7-km2 watershed is located in Gipuzkoa (Northern Spain). It is characteristic of the headwaters watersheds of the area. Most of them are forested and have steep slopes. Annual rainfall is over 1500 mm and many intense rainfall events are observed, among which 18 were selected for this study. Both UH techniques were applied to the rainstorms. The resulting Hydrographs were plotted against registered data and the best fits were determined. According to these results, the GUHR model behaved similarly to Nash's IUH. However, the GUHR method seemed able to reproduce a wider range of rainstorms than Nash's IUH. While analyzing the UHs calculated, seasonal behavior was observed in runoff generation, and different average UHs were proposed for two different periods. This variability was also observed in values adopted by the GUHR model parameter, providing some information about the watershed time response. The dynamic character of the only uncertain parameter, and the model formulation, in which the watershed morphology is reflected, together with the model's simplicity, leads us to consider GUHR as being a promising UH model.
M P Tripathi - One of the best experts on this subject based on the ideXlab platform.
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development of a geomorphological instantaneous Unit Hydrograph model for scantily gauged watersheds
Environmental Modelling and Software, 2008Co-Authors: A Bhadra, N Panigrahy, Rajendra Singh, N S Raghuwanshi, M P TripathiAbstract:In recent years, geomorphological instantaneous Unit Hydrograph (GIUH) approach to estimate the runoff from a watershed due to different storm patterns has gained wide acceptability for watersheds with scanty data. In this study, a user-friendly event based computerized GIUH model, GIUH_CAL, was developed. GIUH_CAL model incorporates an infiltration component. Depending on the availability of soil and infiltration data, the model offers a choice among three methods of infiltration calculation, viz., Richards' equation, phi-index method and Philip two term model. The graphical user interface (GUI) of the model is based on mouse-driven approach with pop-up windows, pull-down menus, sub-menus, toolbar, statusbar and button controls including comprehensive context-sensitive help file. GIUH_CAL model displays generated instantaneous Unit Hydrograph (IUH), Unit Hydrograph (UH) and direct runoff Hydrograph (DRH) of the watershed graphically and processes statistically. Modelling efficiency (ME), coefficient of residual mass (CRM), root mean square error (RMSE) and coefficient of determination (r^2) are used as the performance criteria. The model was tested for two distinctly different watersheds, i.e., a 4th order Guptamani watershed in tropical sub-humid region and a 3rd order Upper Chhokeranala watershed in semi-arid region of India. The results show that model performs satisfactorily for both test watersheds and performance is much better with Richards' equation option of infiltration calculation as compared to phi-index method and Philip two term model.Thus, GIUH_CAL model can be adopted as a standard tool for modelling rainfall-runoff transformation process in scantily gauged watersheds.
P. K. Bhunya - One of the best experts on this subject based on the ideXlab platform.
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Flood Hydrograph with Synthetic Unit Hydrograph Routing
Water Resources Management, 2015Co-Authors: M. K. Bhuyan, Sanjay Kumar, Joygopal Jena, P. K. BhunyaAbstract:Synthetic Unit Hydrographs (SUH) based on geomorphology are used as a tool to produce flood Hydrographs from rainfall records, especially in ungauged and partially gauged catchments. This study presents a flood Hydrograph model formulated on SUH based approach using geomorphologic parameters derived from Survey of India maps and geographical information system (GIS) techniques to simulate basin runoff. It uses linear Muskingum routing model in which the routing parameters are determined from the kinematic approach rather than from runoff data. The model employs the Unit Hydrograph suggested by Central Water Commission (CWC) India, as the discharge data from the sub-catchments and routes the concurrent discharges generated from them to the watershed outlet, and compared with the Unit Hydrograph of the lumped catchment. Application of the model is demonstrated by using data of a small watershed in the Mahanadi basin, India. The study indicates the limitations of the CWC Unit Hydrograph approach both in the small hilly and large plane catchments. It is observed that the CWC Unit Hydrograph (UH) underestimates the peak discharges both for catchments smaller than 200 km 2 with steeper slope and larger than 600 km 2 with flatter slope. The study further emphasizes on using two parameter Gamma distribution for preparation of UH curve instead of adopting standard practice of drawing synthetic Unit Hydrograph using seven known points with approximate curve fitting. Copyright Springer Science+Business Media Dordrecht 2015
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synthetic Unit Hydrograph methods a critical review
The Open Hydrology Journal, 2011Co-Authors: P. K. BhunyaAbstract:The present study critically reviews the synthetic Unit Hydrograph (SUH) methods available in hydrologic lit- erature. The study reveals that the traditional methods of SUH derivation, e.g., Snyder, SCS, traditional methods like Sny- der and TS method that does not yield satisfactory results, and their application to the practical engineering problems is tedious and combursome. On the other hand, probability distribution functions (pdfs) based SUH methods are easy to ap- ply, and easily meet the UH criterion, i.e. the area under the curve is Unity, and rely on a stronger mathematical base and sounder hydrologic perception. The recent pdfs used for deriving UHs in ungauged catchments, address the SUH shapes with more flexibility than the earlier pdfs proposed by (1) for SUH derivation.
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development of optimal and physically realizable Unit Hydrograph
Journal of Hydrologic Engineering, 2006Co-Authors: Sharad K Jain, Vijay P Singh, P. K. BhunyaAbstract:Optimization techniques for deriving a Unit Hydrograph (UH) have received considerable attention. But the UHs derived in some studies are not physically justifiable as the recession limb has a wavy shape. This study extends an existing optimization model by introducing additional constraints to ensure a monotonic decline in the recession limb of the UH. Although there is a marginal deterioration of the objective function, the shape of the developed UH is physically correct. Moreover, the match between the observed and computed direct surface runoff Hydrographs is close.
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parameter estimation of beta distribution for Unit Hydrograph derivation
Journal of Hydrologic Engineering, 2004Co-Authors: P. K. Bhunya, S K Mishra, C S P Ojha, Ronny BerndtssonAbstract:Traditionally used methods for developing a synthetic Unit Hydrograph (SUH) are well known for their limitations. In last few decades, use of probability distribution functions in developing SUHs has received much attention. In this study, the potentials of a three-parameter beta distribution are explored. Using a analogy between the three-parameter beta-distribution shape and the SUH shape, approaches are developed to evaluate the unknown parameters. Based on nondimensional analysis and optimization, a simple accurate relation is introduced to estimate the three parameters of the beta distribution that is useful for Unit Hydrograph derivation. The relation yields results closer to those obtained by an available trial and error procedure. The Unit Hydrographs from the proposed method fit observed Hydrographs better than those from the widely used two-parameter gamma distribution. The potential of the approach is demonstrated using data from different catchments lying within and outside India. The methodology is found to work consistently better in most cases.
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simplified two parameter gamma distribution for derivation of synthetic Unit Hydrograph
Journal of Hydrologic Engineering, 2003Co-Authors: P. K. Bhunya, S K Mishra, Ronny BerndtssonAbstract:Several methods for synthetic Unit Hydrographs are available in the literature. Most of them involve manual, subjective fitting of a Hydrograph through few data points. Because it is difficult, the generated Unit Hydrograph is often left unadjusted for Unit runoff volume. To circumvent this problem, a simplified version of the existing two-parameter gamma distribution is introduced to derive a synthetic Hydrograph more conveniently and accurately than the popular Gray, Soil Conservation Service, and Synder methods. The revised version incorporates the approximate, but accurate, empirical relations developed for the estimation of beta and lambda (factors governing the shape of the dimensionless Unit Hydrograph) from the Nash parameter n (= number of reservoirs). The Marquardt algorithm was used to develop the nonlinear relationships. The applicability of the simplified version is tested on both text and field data. (Less)
