The use of a dimensionless unit hydrograph to derive unit hydrographs for some Pacific Northwest basins

1961 ◽  
Vol 66 (2) ◽  
pp. 521 ◽  
Author(s):  
Donald L. Bender ◽  
John A. Roberson
Keyword(s):  
Pacific Northwest ◽  
Unit Hydrograph ◽  
Dimensionless Unit ◽  
Unit Hydrographs

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.

scholarly journals The Role of Topography on the Shape of Unit Hydrographs in Small and Medium Sized Watersheds through a Physical Model

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2270
Author(s):  
Alicia A. Del Rio ◽  
Aldo I. Ramirez ◽  
Mauricio A. Sanchez
Keyword(s):  
Fuzzy Logic ◽  
Polynomial Regression ◽  
Synthetic Methods ◽  
Main Stream ◽  
Unit Hydrograph ◽  
Watershed Area ◽  
Time To Peak ◽  
Logic Models ◽  
Empirical Relations ◽  
Unit Hydrographs

This study intends to establish the main relations between topographic characteristics of the watershed and the main parameters of the unit hydrograph measured at the outlet. It looks to remove the subjectivity found in traditional synthetic methods and the trial and error setting of the main parameters of the hydrograph. The work was developed through physical experimentation of the rainfall-runoff process using the observed information of different watersheds of Chiapas, Mexico, as the reference. The experiments were carried out on a state-of-the-art semi-automatic runoff simulator, which was designed and built specifically for this study. Polynomial regression and fuzzy logic models were obtained to confirm the hypothesis of hydrological parameters being obtained from topographic data only by assuming uniform precipitation. Empirical relations were found for the peak flow, time to peak, base time and volume of the unit hydrograph and the watershed area, the main stream average slope, and the length of the stream of highest order. The main finding is that a unit hydrograph can be described based only on the watershed area when fuzzy logic models are applied.

scholarly journals Forest watershed runoff changes determined using the unit hydrograph method

2009 ◽  
Vol 55 (No. 2) ◽  
pp. 89-95
Author(s):  
V. Černohous ◽  
P. Kovář
Keyword(s):  
Least Squares ◽  
Least Squares Method ◽  
Forest Stand ◽  
Unit Hydrograph ◽  
Stand Growth ◽  
Total Runoff ◽  
Runoff Changes ◽  
Recession Limb ◽  
Unit Hydrographs ◽  
Maximum Runoff

Unit hydrograph is a basic method to show changes in runoff in the watershed. The investigation of runoff changes was carried out in the U Dvou louček watershed situated at the summit part of the Orlické hory Mts., East Bohemia. The waveform ordinates of recession limbs of unit hydrographs obtained using a common approach had to be approximated by the least-squares method. Final hydrographs reflected both drainage treatment and forest stand growth influencing the runoff from the watershed. Both factors increase culmination in synergy and reduce runoff on the recession limb of the hydrograph. We confirmed increased maximum runoff taking up 25–30% of the total runoff time when waterlogged sites were drained. The culmination increased by 0.2–0.8 mm/hour indicates the runoff increased by 2–8 m<sup>3</sup>/ha/hr.

scholarly journals Applicability of a Spatially Semi-Distributed Hydrological Model for Watershed Scale Runoff Estimation in Northwest Ethiopia

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 923 ◽  
Author(s):  
Demlie Zelelew ◽  
Assefa Melesse
Keyword(s):  
Northwest Ethiopia ◽  
Distributed Hydrological Model ◽  
Unit Hydrograph ◽  
Protection Measures ◽  
Transform Methods ◽  
Model Set ◽  
Loss Method ◽  
Unit Hydrographs ◽  
Blue Nile River Basin ◽  
Ungauged Watersheds

Estimation of runoff is vital forplanning activities in relation to integrated watershed management and flood protection measures. This research was conducted at one of the catchments in Abbay River (upper Blue Nile River) basin to assess the applicabilityof the Hydrologic Engineering Centre Hydrological Modelling Software (HEC-HMS) modelfor simulation of runoff. It was aimed at selecting the best loss and transform methods in the model, as well as testing the applicability of the calibrated model to ungauged watersheds. Two loss methods such as soil conservation service (SCS) and initial and constant methods with two transform methods including SCS and Clark unit hydrographs were considered in the study for selecting the best combinations applicable in the area. While comparing the simulation results of each combination, better results were obtained in the model set containing the initial and constant loss method and SCS unit hydrograph with a Nash-Sutcliff Efficiency (NSE) of 82.8%, R2 of 0.83, and 10.71% of relative bias errors, followed by initial and constant with Clarks unit hydrograph, and it can be used for similar ungauged watersheds.

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.

Recursion formula for unit hydrographs

1986 ◽  
Vol 13 (3) ◽  
pp. 386-388 ◽  
Author(s):  
Beni P. Sangal
Keyword(s):  
Key Words ◽  
Short Duration ◽  
Recursion Formula ◽  
Unit Hydrograph ◽  
Long Duration ◽  
Unit Hydrographs

A recursion formula has been derived that can be used for either converting short-duration unit hydrographs to long-duration ones or long-duration unit hydrographs to short-duration ones. Thus an alternative to developing an S-hydrograph for this purpose is proposed. Examples on the use of the formula have been provided. Key words: hydrograph, hydrology, S-hydrograph, unit hydrograph, unitgraph.

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