Regionalization of rainfall–runoff processes in rice agriculture dominated watersheds

2006 ◽  
Vol 53 (10) ◽  
pp. 131-139 ◽  
Author(s):  
N.V. Rajyalakshmi ◽  
S. Dutta
Keyword(s):  
Rice Field ◽  
Storm Event ◽  
Rainfall Runoff ◽  
Unit Hydrograph ◽  
Stream Network ◽  
Rice Agriculture ◽  
Watershed Response ◽  
Instantaneous Unit Hydrograph ◽  
Daily Water ◽  
Unit Hydrographs

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.

COMPARISON OF DIMENSIONLESS UNIT HYDROGRAPHS IN THAILAND AND TAIWAN

1971 ◽  
Vol 2 (1) ◽  
pp. 23-46 ◽  
Author(s):  
EDMUND F. SCHULZ ◽  
SUBIN PINKAYAN ◽  
CHUMPORN KOMSARTRA
Keyword(s):  
Base Length ◽  
Unit Hydrograph ◽  
Time To Peak ◽  
Dimensionless Unit ◽  
Instantaneous Unit Hydrograph ◽  
Subsurface Runoff ◽  
Tropical Watersheds ◽  
Unit Hydrographs ◽  
Similar Unit ◽  
Two Parameter

The characteristics of dimensionless unit hydrographs were derived from floods from watersheds smaller than 1000 square kilometers located in Thailand. The dimensionless unit hydrographs were expressed as ratios of q/qq as a function of t/tp. These dimensionless unit hydrographs were compared with similar unit hydrographs derived from floods on Taiwan and with the unit hydrographs derived from a mathematical model developed from the two parameter gamma function developed from the theory of the instantaneous unit hydrograph. It was found that the unit hydrographs derived from the Thai watersheds had much longer base length and much longer time to peak than similar unit hydrographs derived from floods on Taiwan. This increase in length of response time is attributed to a larger component of subsurface runoff believed to be present in the floods from tropical watersheds.

Rainfall Runoff Hydrograph Prediction Using Dynamic Wave Based Instantaneous Unit Hydrograph

2020 ◽  
Author(s):  
Minyeob Jeong ◽  
Jongho Kim ◽  
Dae-Hong Kim
Keyword(s):  
Rainfall Intensity ◽  
Wave Model ◽  
Test Results ◽  
Rainfall Runoff ◽  
Unit Hydrograph ◽  
Time To Peak ◽  
Instantaneous Unit Hydrograph ◽  
Runoff Hydrographs ◽  
Dynamic Wave ◽  
Peak Value

<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>

scholarly journals Root selection methods in flood analysis

2003 ◽  
Vol 7 (2) ◽  
pp. 151-161 ◽  
Author(s):  
B. Parmentier ◽  
J. Dooge ◽  
M. Bruen
Keyword(s):  
Fast Response ◽  
Storm Event ◽  
Rainfall Runoff ◽  
Selection Methods ◽  
Slow Response ◽  
Unit Hydrograph ◽  
Total Runoff ◽  
Splitting Parameter ◽  
Matching Procedure ◽  
Selection Of

Abstract. In the 1970s, de Laine developed a root-matching procedure for estimating unit hydrograph ordinates from estimates of the fast component of the total runoff from multiple storms. Later, Turner produced a root selection method which required only data from one storm event and was based on recognising a pattern typical of unit hydrograph roots. Both methods required direct runoff data, i.e. prior separation of the slow response. This paper introduces a further refinement, called root separation, which allows the estimation of both the unit hydrograph ordinates and the effective precipitation from the full discharge hydrograph. It is based on recognising and separating the quicker component of the response from the much slower components due to interflow and/or baseflow. The method analyses the z-transform roots of carefully selected segments of the full hydrograph. The root patterns of these separate segments tend to be dominated by either the fast response or the slow response. This paper shows how their respective time-scales can be distinguished with an accuracy sufficient for practical purposes. As an illustration, theoretical equations are derived for a conceptual rainfall-runoff system with the input split between fast and slow reservoirs in parallel. These are solved analytically to identify the reservoir constants and the input splitting parameter. The proposed method, called "root separation", avoids the subjective selection of rainfall roots in the Turner method as well as the subjective matching of roots in the original de Laine method. Keywords: unit hydrograph,identification methods, z-transform, polynomial roots, root separation, fast andslow response, Nash cascade

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
Keyword(s):  
Central Italy ◽  
Rainfall Runoff ◽  
Unit Hydrograph ◽  
Empirical Relationships ◽  
Instantaneous Unit Hydrograph ◽  
Explicit Consideration ◽  
Design Hydrographs ◽  
Basin Area ◽  
Basin Geomorphology

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.

scholarly journals A Polynomial Method Approximating S-Curve with Limited Availability of Reliable Rainfall Data

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3447
Author(s):  
Kee-Won Seong ◽  
Jang Hyun Sung
Keyword(s):  
Step Response ◽  
Polynomial Method ◽  
Storm Events ◽  
Rainfall Runoff ◽  
Unit Hydrograph ◽  
General Applicability ◽  
Runoff Modeling ◽  
Instantaneous Unit Hydrograph ◽  
S Curve

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.

scholarly journals A measure of watershed nonlinearity: interpreting a variable instantaneous unit hydrograph model on two vastly different sized – watersheds

2005 ◽  
Vol 2 (5) ◽  
pp. 2111-2151
Author(s):  
J. Y. Ding
Keyword(s):  
Shape Factor ◽  
Overland Flow ◽  
Convolution Integral ◽  
Unit Hydrograph ◽  
N Value ◽  
Time To Peak ◽  
The Us ◽  
Instantaneous Unit Hydrograph ◽  
Unit Hydrographs ◽  
A Minor

Abstract. This paper reviews the use of an input-dependent kernel in a linear convolution integral as a quasi-nonlinear approach to unify nonlinear overland flow, channel routing and catchment runoff processes. The conceptual model of a variable kernel or instantaneous unit hydrograph (IUH) is characterized by a nonlinear storage-discharge relation, q=cNsN where the storage exponent N is an index or degree of watershed nonlinearity. When the causative rainfall excess intensity of a unit hydrograph is known, parameters N and c can be determined directly from its shape factor, the product of the unit peak ordinate and the time to peak. The model is calibrated by the shape factor and verified by convolution integral on two watersheds of vastly different sizes, each having a family of four or five unit hydrographs, data of which were published by Childs in 1958 for the Naugatuck River and by Minshall in 1960 for the Edwardsville catchment. For an 11-hectare catchment near Edwardsville in southern Illinois, the US, four moderate storms show an average N value of 1.79, which is 7% higher than the theoretical value of 1.67 by Manning friction law, while the heaviest storm, which is three to six times larger than the next two events in terms of the peak discharge and runoff volume, follows the Chezy law of 1.5. At the other end of scale, for the Naugatuck River at Thomaston in Connecticut, the US, having a drainage area of 186.2 km2, the average N value of 2.28 varies from 1.92 for a minor flood to 2.68 for a hurricane-induced flood, all of which lie between the theoretical value of 1.67 for turbulent overland flow and that of 3.0 for laminar overland flow. Short examples and a spreadsheet template are given to illustrate key steps in generating the direct runoff hydrograph by convolution integral with the 2-parameter variable IUH model.

scholarly journals Regional analysis using the Geomorphoclimatic Instantaneous Unit Hydrograph

2001 ◽  
Vol 5 (1) ◽  
pp. 93-102 ◽  
Author(s):  
M. J. Hall ◽  
A. F. Zaki ◽  
M. M. A. Shahin
Keyword(s):  
Goodness Of Fit ◽  
Linear Regression Analysis ◽  
Regional Analysis ◽  
Total Duration ◽  
Time Interval ◽  
Unit Hydrograph ◽  
Design Flood ◽  
Stream Network ◽  
Channel Characteristics ◽  
Instantaneous Unit Hydrograph

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

scholarly journals Technical note: Cascade of submerged reservoirs as a rainfall–runoff model

2017 ◽  
Vol 21 (9) ◽  
pp. 4649-4661
Author(s):  
Jacek Kurnatowski
Keyword(s):  
Chebyshev Polynomials ◽  
Technical Note ◽  
Model Output ◽  
Rainfall Runoff ◽  
Unit Hydrograph ◽  
Exponential Functions ◽  
Instantaneous Unit Hydrograph ◽  
Rainfall Runoff Model ◽  
Runoff Model

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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