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 Regional analysis using the Geomorphologic Instantaneous Unit Hydrograph (GIUH) method

2014 ◽  
Vol 9 (No. 1) ◽  
pp. 25-30 ◽  
Author(s):  
M.R. Khaleghi ◽  
J. Ghodusi ◽  
H. Ahmadi
Keyword(s):  
High Efficiency ◽  
Linear Regression Analysis ◽  
Regional Analysis ◽  
Suitable Model ◽  
Rainfall Runoff ◽  
Unit Hydrograph ◽  
Design Flood ◽  
Ungauged Catchments ◽  
Northern Iran ◽  
Simulation Accuracy

The construction of design flood hydrographs for ungauged drainage areas has traditionally been approached by regionalization, 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 generalized rainfall statistics. In the present study, Geomorphologic Instaneous Unit Hydrograph (GIUH) was applied to simulate the rainfall-runoff process and also to determine the shape and dimensions of outlet runoff hydrographs in a 37.1 km<sup>2</sup> area in the Ammameh catchment, located at northern Iran. The first twenty-one equivalent rainfall-runoff events were selected, and a hydrograph of outlet runoff was calculated for each event. An intercomparison was made for the three applied approaches in order to propose a suitable model approach that is the overall objective of this study. Hence, the time to peak and peak flow of outlet runoff in the models were then compared, and the model that most efficiently estimated hydrograph of outlet flow for similar regions was determined. Statistical analyses of the models demonstrated that the GIUH model had the smallest main relative and square error. The results obtained from the study confirmed the high efficiency of the GIUH and its ability to increase simulation accuracy for runoff and hydrographs. The modified GIUH approach as described is therefore recommended for further investigation and intercomparison with regression-based regionalization methods.

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.

Geomorphological Approach to the Skewed Shape of Instantaneous Unit Hydrograph

2015 ◽  
Vol 48 (2) ◽  
pp. 91-103
Author(s):  
Joo-Cheol Kim ◽  
◽  
Kwansue Jung ◽  
Dong Kug Jeong
Keyword(s):  
Unit Hydrograph ◽  
Instantaneous Unit Hydrograph

scholarly journals A Comparison of Some Methods of Deriving the Instantaneous Unit Hydrograph

1985 ◽  
Vol 16 (1) ◽  
pp. 1-10 ◽  
Author(s):  
V. P. Singh ◽  
C. Corradini ◽  
F. Melone
Keyword(s):  
Peak Flow ◽  
Central Italy ◽  
Effective Rainfall ◽  
Unit Hydrograph ◽  
Time To Peak ◽  
Wide Range ◽  
Instantaneous Unit Hydrograph ◽  
Similar Accuracy ◽  
Two Parameters ◽  
Range Of Values

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.

scholarly journals The anthochron as a building block of flower development

2016 ◽  
Vol 51 (8) ◽  
pp. 899-904
Author(s):  
Nereu Augusto Streck ◽  
Natalia Teixeira Schwab
Keyword(s):  
Building Block ◽  
Flower Development ◽  
Field Experiments ◽  
Linear Regression Analysis ◽  
Time Interval ◽  
Simple Linear Regression ◽  
Vegetative Development ◽  
Flower Opening ◽  
Factors Affecting ◽  
Opening Phase

Abstract: Plant vegetative development has been widely described using the phyllochron concept, but little effort has been made to describe flower development during the reproductive phase. The objective of this work was to present the anthochron, through a review of the literature, as a building block of flower development, mainly during the flower opening phase. The anthochron is the time interval needed for two subsequent flowers to achieve the same developmental stage, with units of time in days or in ºC day per flower. The concept of anthochron fulfills part of the lack of studies on flower development, since it is considered a building block of the flower opening process. The anthochron can be measured from field experiments or estimated by a simple linear regression analysis. So far, the anthochron has only been quantified in Gladiolus x grandiflorus Hort. Therefore, factors affecting the anthochron still need to be determined in order to pinpoint their effect on the flower opening rate.

scholarly journals A Hybrid MPI-OpenMP Parallel Algorithm for the Assessment of the Multifractal Spectrum of River Networks

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3122
Author(s):  
Leonardo Primavera ◽  
Emilia Florio
Keyword(s):  
River Basin ◽  
Message Passing Interface ◽  
Multifractal Spectrum ◽  
Computation Method ◽  
Processing Unit ◽  
Unit Hydrograph ◽  
Fast Evaluation ◽  
Correlation Integral ◽  
Central Processing ◽  
Instantaneous Unit Hydrograph

The possibility to create a flood wave in a river network depends on the geometric properties of the river basin. Among the models that try to forecast the Instantaneous Unit Hydrograph (IUH) of rainfall precipitation, the so-called Multifractal Instantaneous Unit Hydrograph (MIUH) by De Bartolo et al. (2003) rather successfully connects the multifractal properties of the river basin to the observed IUH. Such properties can be assessed through different types of analysis (fixed-size algorithm, correlation integral, fixed-mass algorithm, sandbox algorithm, and so on). The fixed-mass algorithm is the one that produces the most precise estimate of the properties of the multifractal spectrum that are relevant for the MIUH model. However, a disadvantage of this method is that it requires very long computational times to produce the best possible results. In a previous work, we proposed a parallel version of the fixed-mass algorithm, which drastically reduced the computational times almost proportionally to the number of Central Processing Unit (CPU) cores available on the computational machine by using the Message Passing Interface (MPI), which is a standard for distributed memory clusters. In the present work, we further improved the code in order to include the use of the Open Multi-Processing (OpenMP) paradigm to facilitate the execution and improve the computational speed-up on single processor, multi-core workstations, which are much more common than multi-node clusters. Moreover, the assessment of the multifractal spectrum has also been improved through a direct computation method. Currently, to the best of our knowledge, this code represents the state-of-the-art for a fast evaluation of the multifractal properties of a river basin, and it opens up a new scenario for an effective flood forecast in reasonable computational times.

scholarly journals EXPLORATION OF INTERCALATED KAOLINITE CLAY FOR THE UPTAKE OF BASIC DYE BY ADSORPTION − EQUILIBRIUM, KINETICS AND THERMODYNAMIC STUDIES

2021 ◽  
Vol 46 (1) ◽  
Author(s):  
C. E. Chigbundu ◽  
K. O. Adebowale
Keyword(s):  
Experimental Data ◽  
Linear Regression ◽  
Goodness Of Fit ◽  
Linear Regression Analysis ◽  
Dye Adsorption ◽  
Batch Adsorption ◽  
Sem Images ◽  
Kaolinite Clay ◽  
Non Linear ◽  
The Impact

Dyes are complex and sensitive organic chemicals which exposes microbial populations, aquatic lives and other living organisms to its toxic effects if their presence in water bodies or industrial effluents are not properly handled. This work therefore, comparatively studied the adsorption efficiencies of natural raw kaolinite (NRK) clay adsorbent and dimethyl sulphoxide (DMSO) faciley intercalated kaolinite clay (DIK) adsorbent for batch adsorption of Basis Red 2 (BR2) dye. The impact of varying the contact time, temperature and other operating variables on adsorption was also considered. The two adsorbents were characterized using SEM images, FTIR and XRD patterns. Linear and non-linear regression analysis of different isotherm and kinetic models were used to describe the appropriate fits to the experimental data. Error analysis equations were also used to measure the goodness-of-fit. Langmuir isotherm model best described the adsorption as being monolayer on homogenous surfaces while Kinetic studies showed that Elovich model provides the best fit to experimental data. The adsorption capacities of NRK and DIK adsorbents for the uptake of BR2 were 16.30 mg/g and 32.81 mg/g, respectively (linear regression) and 19.30 mg/g and 30.81 mg/g, respectively (non-linear regression). The thermodynamic parameter, ∆G showed that BR2 dye adsorption onto the adsorbents were spontaneous. DIK adsorbent was twice efficient compared with NRK for the uptake of BR2 dye.

scholarly journals Quality of Life in Patients with Cerebral Venous Sinus Thrombosis: A Study on Physical, Psychological, and Social Status of Patients in Long-term

2021 ◽  
Vol 24 (1) ◽  
pp. 15-21
Author(s):  
Danesh Kajbaf ◽  
Kamyar Moradi ◽  
Hossein Shamshiri ◽  
Sayna Bagheri ◽  
Reza Rikhtegar ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Sinus Thrombosis ◽  
Linear Regression Analysis ◽  
Cerebral Venous Sinus Thrombosis ◽  
Venous Sinus ◽  
Time Interval ◽  
Residual Symptoms ◽  
Venous Sinus Thrombosis

Background: Cerebral venous sinus thrombosis (CVST) causes significant problems for patients in the working age and may therefore negatively affect their quality of life (QOL). In the present study, we sought to evaluate the QOL and its predictors in subjects with CVST. Methods: This observational, prospective study investigated several outcomes of 56 CVST patients after thrombosis onset. Demographic characteristics, medical history, neurological signs and symptoms during hospitalization, and the employment status of the patients were retrospectively collected. Stroke-related functional scales, including the modified Rankin Scale (mRS) and Barthel Index (BI) were employed. For physical and mental aspects of the QOL, we used the validated Persian version of the Stroke Specific Quality of Life (SS-QOL) scale. Results: The physical and functional outcomes in the long-term were promising according to mRS and BI tools, as well as the improved rate of return to work. Mental domains of the SS-QOL, such as energy and personality represented the lowest scores. According to the multiple linear regression analysis, lower mRS score, and longer time interval between CVST onset and interview were associated with higher physical function of the patients while their better mental function was correlated with lower mRS score and thrombosis in merely one cerebral venous. Conclusion: CVST patients experience an acceptable alleviation of the primary physical disabilities, while residual symptoms, mostly in psychologic/mental domains, impair their QOL.

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