scholarly journals Derivation of S-Curve from Oscillatory Hydrograph Using Digital Filter

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1456
Author(s):  
Kee-Won Seong ◽  
Jang Hyun Sung
Keyword(s):  
Digital Filter ◽  
Model Performance ◽  
Performance Criteria ◽  
Rainfall Runoff ◽  
Small Watershed ◽  
Unit Hydrograph ◽  
Time To Peak ◽  
S Curve ◽  
And Performance ◽  
Smooth Data

An oscillatory S-curve causes unexpected fluctuations in a unit hydrograph (UH) of desired duration or an instantaneous UH (IUH) that may affect the constraints for hydrologic stability. On the other hand, the Savitzky–Golay smoothing and differentiation filter (SG filter) is a digital filter known to smooth data without distorting the signal tendency. The present study proposes a method based on the SG filter to cope with oscillatory S-curves. Compared to previous conventional methods, the application of the SG filter to an S-curve was shown to drastically reduce the oscillation problems on the UH and IUH. In this method, the SG filter parameters are selected to give the minimum influence on smoothing and differentiation. Based on runoff reproduction results and performance criteria, it appears that the SG filter performed both smoothing and differentiation without the remarkable variation of hydrograph properties such as peak or time-to peak. The IUH, UH, and S-curve were estimated using storm data from two watersheds. The reproduced runoffs showed high levels of model performance criteria. In addition, the analyses of two other watersheds revealed that small watershed areas may experience scale problems. The proposed method is believed to be valuable when error-prone data are involved in analyzing the linear rainfall–runoff relationship.

scholarly journals Integrating XAJ Model with GIUH Based on Nash Model for Rainfall-Runoff Modelling

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 772 ◽  
Author(s):  
Yingbing Chen ◽  
Peng Shi ◽  
Simin Qu ◽  
Xiaomin Ji ◽  
Lanlan Zhao ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Network Flow ◽  
Model Performance ◽  
Efficiency Coefficient ◽  
Effective Rainfall ◽  
Unit Hydrograph ◽  
Nash Model ◽  
Average Flow Velocity ◽  
Time To Peak ◽  
Flood Estimation

The geomorphologic instantaneous unit hydrograph (GIUH) is an applicable approach that simulates the runoff for the ungauged basins. The nash model is an efficient tool to derive the unit hydrograph (UH), which only requires two items, including the indices n and k. Theoretically, the GIUH method describes the process of a droplet flowing from which it falls on to the basin outlet, only covering the flow concentration process. The traditional technique for flood estimation using GIUH method always uses the effective rainfall, which is empirically obtained and scant of accuracy, and then calculates the convolution of the effective rainfall and GIUH. To improve the predictive capability of the GIUH model, the Xin’anjiang (XAJ) model, which is a conceptual model with clear physical meaning, is applied to simulate the runoff yielding and the slope flow concentration, integrating with the GIUH derived based on Nash model to compute the river network flow convergence, forming a modified GIUH model for flood simulation. The average flow velocity is the key to obtain the indices k, and two methods to calculate the flow velocity were compared in this study. 10 flood events in three catchments in Fujian, China are selected to calibrate the model, and six for validation. Four criteria, including the time-to-peak error, the relative peak flow error, the relative runoff depth error, and the Nash–Sutcliff efficiency coefficient are computed for the model performance evaluation. The observed runoff value and simulated series in validation stage is also presented in the scatter plots to analyze the fitting degree. The analysis results show the modified model with a convenient calculation and a high fitting and illustrates that the model is reliable for the flood estimation and has potential for practical flood forecasting.

scholarly journals Assessment of the Performance of Rainfall-Runoff Model GR4J to Simulate Streamflow in Ouémé Watershed at Bonou’s outlet (West Africa)

2018 ◽  
Author(s):  
Domiho Japhet Kodja ◽  
Gil Mahé ◽  
Ernest Amoussou ◽  
Michel Boko ◽  
Jean-Emmanuel Paturel
Keyword(s):  
Climate Change ◽  
High Water ◽  
High Flow ◽  
Performance Criteria ◽  
Rainfall Runoff ◽  
Flow Rates ◽  
Water Flows ◽  
Rainfall Runoff Model ◽  
And Performance ◽  
Runoff Model

The study aims to analyze the performance criteria of the GR4J model to reproduce high water flows in the Ouémé watershed at Bonou's outlet which has been vulnerable to climate change in recent decades. The methodology focused on the use of daily climatological and hydrometric data extracted from files of National Directorate of Meteorology, and General Directorate of Water; they were supplemented by those of SIEREM/HSM dataset over the period 1961-2015. The rainfall was regionalized using Thiessen method. The performance of the GR4J model was assessed with NSE, RMSE and KGE criteria. The results indicate that the study area is marked by rainfall variabilities and detection of two breakpoints (1968 and 1987) which divide the series into three sub-periods; these discontinuities have repercussions on the streamflow. It's found that GR4J model overestimates the streamflow during the low water period and underestimates them in high water. However, the efficiency and performance criteria NSE, RMSE and KGE calculated on high water flow rates are better in calibration than in validation. The KGE values are range between 83-85% in calibration and 56-68% during validation, which gives to GR4J model the efficiency and performance to reproduce high flow rates in the study area

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 Research on the initial abstraction – storage ratio and its effect on hydrograph simulation at a watershed in Greece

2007 ◽  
Vol 4 (4) ◽  
pp. 2169-2204 ◽  
Author(s):  
E. A. Baltas ◽  
N. A. Dervos ◽  
M. A. Mimikou
Keyword(s):  
Empirical Equation ◽  
Storm Events ◽  
Rainfall Runoff ◽  
Unit Hydrograph ◽  
Time To Peak ◽  
Initial Abstraction ◽  
Time Period ◽  
The Difference ◽  
Runoff Events

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.

Evaluation of 42 lumped rainfall-runoff models for the Wairau River catchment, New Zealand, using the MARRMoT toolbox

2021 ◽  
Author(s):  
Alina Peesel ◽  
Thomas Wöhling
Keyword(s):  
New Zealand ◽  
Catchment Area ◽  
Model Performance ◽  
Performance Criteria ◽  
Rainfall Runoff ◽  
Flow Data ◽  
Technical Problems ◽  
River Catchment ◽  
The World ◽  
Lumped Models

<p>For decades, lumped rainfall-runoff models have been used for hydrological analysis and forecasting such as operational flood forecasting. However, the accuracy of model forecasts depends on the ability of the model to approximate the dominant hydrological processes of the catchment under consideration. These processes are site specific and, therefore, the choice of a particular model is challenging. </p><p>A large number of hydrological models has been developed and applied in various regions of the world. Model choice has often been hampered in the past by technical problems such as different programming languages, different software platforms, and different input formats and requirements.</p><p>The Modular Assessment of Rainfall Runoff Model Toolbox (MARRMoT) unites 46 lumped models from around the world within the same Matlab® framework with standardized inputs. The model equations have been simplified and adapted for this purpose. As a result, it is possible to test a large number of different models with comparatively little effort. The models implemented in MARRMoT vary in their structural complexity and have between 1-24 parameters and between 1-8 storages.</p><p>Here MARRMoT was used in order to find a model or model ensemble suitable for the simulation of precipitation-runoff relationships in the Wairau River catchment, New Zealand. The catchment area is assumed to have predominantly homogeneous runoff-generating properties. Model input data (precipitation and potential evapotranspiration) was derived from the Virtual Climate Station Network by National Institute of Water and Atmospheric Research, NZ.</p><p>In a first scenario, 42 selected models from MARRMoT were calibrated for the Wairau River catchment using 45 years of Wairau River flow data, an in-built nonlinear unconstrained optimization algorithm and the model fitness criteria Kling-Gupta-Efficiency (KGE). In two further scenarios, calibrations using the KGE with inversely transformed flows (KGEi) as well as a mixed form of the two criteria (KGEm) were realized. </p><p>Model performance was further evaluated based on different performance criteria such as NSE, RMSE and R². It was demonstrated that the model ranking depends on the choice of the performance.</p><p>Evaluating the model performance for the different calibration scenarios showed that a few models with very different structures performed well to reproduce the flow data. No decisive structural feature could be identified which all models have in common and which led to a good representation of the rainfall-runoff processes in the Wairau River catchment. However, the differentiated consideration of flow routing and a high degree of flexibility seem to benefit model performance. Deficits in the modeling can be seen in the discharge peaks, which are not correctly simulated by many models. The simulation of fast direct runoff with lumped models seems to be less accurate for the relatively large catchment area of ​​the Wairau River (3430 km²).</p><p>Eventually, three models (GR4J, FLEX-I and HBV-96) demonstrated a high performance in all three calibration scenarios and were identified as suitable for further use in the Wairau River catchment.</p>

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 Rainfall-Runoff Modeling of the Nested Non-Homogeneous Sava River Sub-Catchments in Slovenia

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 128 ◽  
Author(s):  
Katarina Lavtar ◽  
Nejc Bezak ◽  
Mojca Šraj
Keyword(s):  
Water System ◽  
Model Performance ◽  
Performance Criteria ◽  
Meteorological Variables ◽  
Hydrological Models ◽  
Rainfall Runoff ◽  
Runoff Modeling ◽  
Hydrogeological Characteristics ◽  
Sava River ◽  
Runoff Potential

Rainfall-runoff modeling is nowadays applied for water resources management, water system design, real-time forecasting, flood design and can be carried out by using different types of hydrological models. In this study, we focused on lumped conceptual hydrological models and their performance in diverse sub-catchments of the Sava River in Slovenia, related to their size and non-homogeneity. We evaluated the difference between modeled and measured discharges of selected discharge gauging stations, using different model performance criteria that are usually applied in hydrology, connecting the results to geospatial analysis of geological and hydrogeological characteristics, land use, runoff potential, proportion of agglomeration and various meteorological variables. Better model performance was obtained for catchments with a higher runoff potential and with less variations in meteorological variables. Regarding the number of used parameters, the results indicated that the tested Genie Rural 6-parameter Journalier (GR6J) model with 6 parameters performed better than the Genie Rural 4-parameter Journalier (GR4J) model with 4 parameters, especially in the case of larger sub-catchments. These results illustrate the comprehensive nature of lumped models. Thus, they yield good performance in case of the catchments with indistinguishable characteristics.

scholarly journals Impacts of precipitation and topographic conditions on the model simulation in the north of China

2020 ◽  
Author(s):  
Long Sun ◽  
Zhijia Li ◽  
Ke Zhang ◽  
Tingting Jiang
Keyword(s):  
Model Simulation ◽  
Model Performance ◽  
Performance Criteria ◽  
Generation Process ◽  
Rainfall Runoff ◽  
Runoff Generation ◽  
Structure Selection ◽  
The North ◽  
The Impact ◽  
Selection Of

Abstract The evaluation of hydrological models for a specific catchment is normally based on the model performance according to the selected performance criteria. However, the catchment rainfall-runoff characteristics could be used for the selection of a suitable hydrological model in study area, which, also, for the problem solve of the model application in ungauged basins. In this study, six conceptual models were applied in three semi-humid or semi-arid catchments to investigate the correlation between catchment characteristics and model structure selection. In addition, the impacts of precipitation and topography in model simulation were analyzed. The results show that runoff generation are highly impacted by catchment topographic index and land cover change, and the influence of slope for river channel is greater than mean slope for the whole catchment due to the runoff generation for partial area. For the catchments under similar climate condition, the impact of topographic features for runoff generation process is greater than the difference of precipitation. It indicates that for a specific catchment, the selection of appropriate model should base on better understanding of the rainfall-runoff relationship. The method of incorporating additional runoff generation module in the traditional model can significantly improve the accuracy of flood simulation.

Sign in / Sign up

Export Citation Format

Share Document