Some Remarks on the Use of GIUH in the Hydrological Practice

1995 ◽  
Vol 26 (4-5) ◽  
pp. 297-312 ◽  
Author(s):  
C. Corradini ◽  
F. Melone ◽  
V. P. Singh

The geomorphologic instantaneous unit hydrograph (GIUH) as a component of rainfall-runoff models directed to the determination of design hydrographs in ungaged basins is investigated. Specifically, we first performed a sensitivity analysis of the GIUH to errors in the basin lag estimated by commonly used empirical relationships involving basin area. Then, the details required in representing the geomorphologic features in the GIUH estimate for fixed basin lag, L, were examined. Real basins located in Central Italy were selected; they range in area from 12 km2 to 4,147 km2 and are characterized by a significant variability in the drainage channel density, D. It was found that given L a minimum detail was necessary in representing basin geomorphology. Further, the estimate of L through basin area led to large errors in computing design hydrographs for a few small basins. An explicit consideration of D is suggested in order to eliminate this shortcoming.

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3447
Author(s):  
Kee-Won Seong ◽  
Jang Hyun Sung

A methodology named the step response separation (SRS) method for deriving S-curves solely from the data for basin runoff and the associated instantaneous unit hydrograph (IUH) is presented. The SRS method extends the root selection (RS) method to generate a clearly separated S-curve from runoff incorporated in mathematical procedure utilizing the step response function. Significant improvements in performance are observed in separating the S-curve with rainfall. A procedure to evaluate the hydrologic stability provides ways to minimize the oscillation of the S-curve associated with the determination of infiltration and baseflow. The applicability of the SRS method to runoff reproduction is examined by comparison with observed basin runoff based on the RS method. The SRS method applied to storm events for the Nenagh basin resulted in acceptable S-curves and showed its general applicability to optimization for rainfall-runoff modeling.


1985 ◽  
Vol 16 (1) ◽  
pp. 1-10 ◽  
Author(s):  
V. P. Singh ◽  
C. Corradini ◽  
F. Melone

The geomorphological instantaneous unit hydrograph (IUH) proposed by Gupta et al. (1980) was compared with the IUH derived by commonly used time-area and Nash methods. This comparison was performed by analyzing the effective rainfall-direct runoff relationship for four large basins in Central Italy ranging in area from 934 to 4,147 km2. The Nash method was found to be the most accurate of the three methods. The geomorphological method, with only one parameter estimated in advance from the observed data, was found to be little less accurate than the Nash method which has two parameters determined from observations. Furthermore, if the geomorphological and Nash methods employed the same information represented by basin lag, then they produced similar accuracy provided the other Nash parameter, expressed by the product of peak flow and time to peak, was empirically assessed within a wide range of values. It was concluded that it was more appropriate to use the geomorphological method for ungaged basins and the Nash method for gaged basins.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yingbing Chen ◽  
Peng Shi ◽  
Xiaomin Ji ◽  
Simin Qu ◽  
Lanlan Zhao ◽  
...  

Abstract The determination of characteristic flow velocity is a hydrodynamic problem needs to be solved in the application of geomorphologic instantaneous unit hydrograph (GIUH) for runoff simulation in areas with no or limited data. In this study, 120 watersheds are collected to construct a regression model; 85 of these basins are used for regression analysis, and the 35 remaining basins are utilized to verify the feasibility of the constructed model. Random forest algorithm is applied to screen out important geomorphologic factors from the 16 extracted factors that may affect flow velocity. Multivariate regression is used to establish the numerical relationship between velocity and the selected factors. Sensitivity analysis of each adopted factor in the constructed model is conducted using the LH-OAT method. The rationality and feasibility of the regression model are validated by comparing the flow velocity calculation with a previous approach, which is also calculated based on geomorphological parameters. Subsequently, the runoff simulation based on the GIUH model is evaluated using the proposed technique. Results demonstrate that the proposed formula possesses high fitting accuracy and can be easily used to calculate flow velocity and generate GIUH.


2006 ◽  
Vol 53 (10) ◽  
pp. 131-139 ◽  
Author(s):  
N.V. Rajyalakshmi ◽  
S. Dutta

An approach for computing the instantaneous unit hydrograph of rice agriculture dominated watesheds is proposed using the topology and hydraulic charcterstics of its stream network and the hydrologic behaviour of the rice agriculture area. The effect of rice agriculture on the watershed response is considered as partial sink areas. The sink factor, a time-variant weight factor for a particular storm event, is computed from the daily water balanace equation of the rice field. The critcal features of the simulated instantaneous unit hydrographs in three gauged watersheds located in the river Mahanadi, India were then compared with that of the observed 24-hr unit hydrograph. The comparison shows a significant correlation between the two results.


2014 ◽  
Vol 14 (7) ◽  
pp. 1819-1833 ◽  
Author(s):  
A. Candela ◽  
G. Brigandì ◽  
G. T. Aronica

Abstract. In this paper a procedure to derive synthetic flood design hydrographs (SFDH) using a bivariate representation of rainfall forcing (rainfall duration and intensity) via copulas, which describes and models the correlation between two variables independently of the marginal laws involved, coupled with a distributed rainfall–runoff model, is presented. Rainfall–runoff modelling (R–R modelling) for estimating the hydrological response at the outlet of a catchment was performed by using a conceptual fully distributed procedure based on the Soil Conservation Service – Curve Number method as an excess rainfall model and on a distributed unit hydrograph with climatic dependencies for the flow routing. Travel time computation, based on the distributed unit hydrograph definition, was performed by implementing a procedure based on flow paths, determined from a digital elevation model (DEM) and roughness parameters obtained from distributed geographical information. In order to estimate the primary return period of the SFDH, which provides the probability of occurrence of a hydrograph flood, peaks and flow volumes obtained through R–R modelling were treated statistically using copulas. Finally, the shapes of hydrographs have been generated on the basis of historically significant flood events, via cluster analysis. An application of the procedure described above has been carried out and results presented for the case study of the Imera catchment in Sicily, Italy.


Author(s):  
Jusatria Jusatria ◽  
Syahnandito Syahnandito ◽  
M Gasali M ◽  
Rezky Kinanda

The imbalance that occurs between the availability of water and the water needs needed in Indragiri Hilir requires a conseptual review and evaluation. The all-time distribution of water availability is greatly influenced by the distribution of rain throughout the year. Conceptual analysis of water discharge with the help of IHACRES software can help analyze DAS indragiri Hilir discharge. Rainfall-runoff modeling is used to predict the value against the runoff, using the IHACRES model. The IHACRES model produces nonlinear loss module parameters and linear unit hydrograph modules. AWLR will be used, namely Bt. Kuantan Rengat station, Rain Data which will be used from Tembilahan station and climatology used from Air Molek  station. Determination of success in the model used the equations R2 and R to calculate the deviation that occurs. The calibration, verification and simulation phases begin in 2010-2015. The results of conceptual analysis of water discharge in Indragiri Hilir watershed, mainstay discharge results for irrigation purposes with a probability of 80% maximum discharge occurred in February by 4.33 m3 / s and minimum discharge occurred in April by 0.34 m3/s. Overall availability of water on site is available throughout the year. but it cannot be used for hydropower needs because the available discharge may be affected by tidal factors.   Ketidakseimbangan yang terjadi antara ketersediaan air dan kebutuhan air yang diperlukan di Indragiri Hilir memerlukan peninjauan dan evaluasi yang konseptual. Distribusi ketersedian air sepanjang waktu sangat dipengaruhi oleh distribusi hujan  sepanjang tahun . Analisis konseptual debit air dengan bantuan software IHACRES dapat membantu menganalisis debit DAS indragiri hilir. Pemodelan rainfall-runoff digunakan untuk   memprediksi nilai terhadap runoff salah satunya yaitu menggunakan model IHACRES. Model IHACRES menghasilkan parameter nonlinier loss module dan linier unit hydrograph module. AWLR akan digunakan yaitu stasiun Bt. Kuantan Rengat, Data Hujan yang akan digunakan  yaitu dari stasiun Tembilahan dan klimatologi yang digunakan dari stasiun Air Molek. Penentuan  keberhasilan pada model digunakan persamaan R2 dan R untuk menghitung simpangan yang terjadi. Tahap  kalibrasi, verifikasi dan simulasi dimulai tahun 2010-2015. Hasil analisis konseptual debit air pada DAS Indragiri Hilir, hasil debit andalan untuk keperluan irigasi dengan probabilitas 80% debit maksimum terjadi pada bulan Februari sebesar 4,33 m3/s dan debit minimum terjadi pada bulan April sebesar 0,34 m3/s. Secara keseluruhan ketersediaan air di lokasi tersedia sepanjang tahun. tetapi tidak bisa digunakan untuk kebutuhan PLTA karena debit yang tersedia mungkin dipengaruhi faktor pasang surut    


2020 ◽  
Author(s):  
Minyeob Jeong ◽  
Jongho Kim ◽  
Dae-Hong Kim

<p>A method to predict runoff based on the instantaneous unit hydrograph and dynamic wave approximation is proposed. The method is capable of generating IUH of a watershed without the need of observed rainfall and runoff data, and only topography and surface roughness of a watershed are needed. IUHs were generated using a dynamic wave model and S-hydrograph method, and IUH generated was a function of both watershed and rainfall properties. The ordinate of IUH depends on the rainfall intensities, and the peak value of IUH was proportional to the rainfall intensity while the time to peak of the IUH was inversely proportional to the rainfall intensity.  Corresponding IUHs for different rainfall intensities were used to generate runoff hydrographs. Since the IUH is generated using a dynamic wave model, it can be a tool to physically simulate the rainfall-runoff processes. Also, nonlinear rainfall-runoff relationship can be taken into account by expressing IUH as a function of rainfall excess intensity. Several test results in ideal basins and in a real watershed show that the proposed method has a good capability in predicting runoff, while several limitations remain.</p><p>Keywords: rainfall-runoff, instantaneous unit hydrograph, dynamic wave model</p>


2007 ◽  
Vol 4 (4) ◽  
pp. 2169-2204 ◽  
Author(s):  
E. A. Baltas ◽  
N. A. Dervos ◽  
M. A. Mimikou

Abstract. The present research was conducted at an experimental watershed in the prefecture of Attica, Greece, using the selected observed rainfall-runoff events from a four-year time period. The objectives of this study were two: The first was the determination of the initial abstraction Ia – watershed storage S ratio. The average ratio (Ia/S) was equal to 0.014. The corresponding ratio at a subwatershed was 0.037. The difference was attributed to the different spatial distribution of landuses at the extent of the watershed. The second objective of the study was to examine the effect of the SCS empirical equation on hydrograph simulation. This was investigated through the comparison between the observed and two different simulated hydrographs at each one out of eighteen selected storm events. The simulated hydrographs were calculated by applying on the watershed's unit hydrograph two time distributions of excess rainfall that derived from the SCS method using two different approaches. In the first approach, the initial abstraction was determined from the observed rainfall-runoff data, while in the second, it was calculated using the SCS empirical equation. It was found that the SCS empirical equation estimates greater amount of initial abstraction and leads to the delayed start of the excess rainfall and the simulated runoff. This resulted in the overestimation of the peak flow rate and the time to peak at the majority of the storm events.


2017 ◽  
Vol 21 (9) ◽  
pp. 4649-4661
Author(s):  
Jacek Kurnatowski

Abstract. The rainfall–runoff conceptual model as a cascade of submerged linear reservoirs with particular outflows depending on storages of adjoining reservoirs is developed. The model output contains different exponential functions with roots of Chebyshev polynomials of the first kind as exponents. The model is applied to instantaneous unit hydrograph (IUH) and recession curve problems and compared with the analogous results of the Nash cascade. A case study is performed on a basis of 46 recession periods. Obtained results show the usefulness of the model as an alternative concept to the Nash cascade.


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