scholarly journals NUMERICAL SIMULATION OF THE RAINFALL-RUNOFF PROCESS ON A DAILY BASIS

1973 ◽  
Vol 4 (3) ◽  
pp. 171-190 ◽  
Author(s):  
STEEN ASGER NIELSEN ◽  
EGGERT HANSEN
Keyword(s):  
Moisture Content ◽  
Potential Evapotranspiration ◽  
Daily Basis ◽  
Major Influence ◽  
Model Parameters ◽  
Rainfall Runoff ◽  
Frozen Ground ◽  
Statistical Measures ◽  
Simulation Results ◽  
Physical Elements

A digital model has been developed for the simulation of the rainfall-runoff process of rural watersheds. Input data are daily values of precipitation and temperature together with mean monthly potential evapotranspiration. The model produces daily values of streamflow as well as information on the time variation of the soil moisture content. In all, ten model parameters have to be identified, seven of which have a major influence on the performance of the model. The model operates by accounting continuously for the moisture content in four different and mutually interrelated storages representing physical elements in the watershed. It has been applied to three different Danish watersheds. Several statistical measures of accuracy have been utilized for a quantitative evaluation of the simulation results. The simulations demonstrate that the main shortcomings of the model are due to the lack of a procedure accounting for frozen ground during extended periods of frost, which could improve some of the simulation results during winter and spring.

scholarly journals INFLUENCE OF MODEL PARAMETERS' SPATIAL DISTRIBUTIONS ON RAINFALL-RUNOFF SIMULATION RESULTS

2000 ◽  
Vol 44 ◽  
pp. 217-222
Author(s):  
Y. TACHIKAWA ◽  
M. FUKUMITSU ◽  
Y. ICHIKAWA ◽  
M. SHIIBA ◽  
K. TAKARA
Keyword(s):  
Model Parameters ◽  
Spatial Distributions ◽  
Rainfall Runoff ◽  
Runoff Simulation ◽  
Simulation Results

scholarly journals Evaluasi Pengaruh Jumlah dan Posisi Stasiun Curah Hujan pada Simulasi Aliran Limpasan Di Sungai Ping, Thailand

2018 ◽  
Vol 14 (1) ◽  
pp. 31-46
Author(s):  
Muchamad Wahyu Trinugroho
Keyword(s):  
Hydrologic Model ◽  
Peak Discharge ◽  
Model Parameters ◽  
Observation Data ◽  
Discharge Condition ◽  
Rainfall Runoff ◽  
Northern Thailand ◽  
Run Off ◽  
Simulation Results ◽  
Best Fit

The number and distribution of rainfall stations areneeded to simulate rainfall-run off transformation on hydrologic model. However, the availability of stations varies in watershed. The study aims to assess theinfluence of numberand distribution rainfall stations by a modelling approachto simulate run-off process. The use of HEC-HMS model is tocalibrate model parameters and simulaterun-offon 4 scenarios in Mae Caem Watershed (3,826 km2), Northern Thailand. The result shows the calibrated model parameters of 13 stationsare very satisfied by 0.826 of Nash coefficient. Based on the simulation result, the condition of 6 stations demonstrate the best fit regarding observation data by R2 = 0.927; the lowest correlation is three rainfall stations by 0.795 of R2. Also, simulated runoff rainfall for six stations (condition2) show results close to the observation discharge. Condition 1 (all stations) is somewhat higher than condition tworegarding pattern and peak discharge. Another result shows simulation of peak discharge condition 3 (station number 2, 5, and 13) has overestimate of observation discharge and condition 5 shows underestimate result to observation discharge. Overall the simulation results have met Nash's criteria, while the best results are in simulation with 6 stations (condition 2). Thus the number and position of rainfall stations have an influence on the modeling of rainfall runoff in the Ping River, Mae Caem Watershed.

scholarly journals Modeling of German Low Voltage Cables with Ground Return Path

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1265 ◽  
Author(s):  
Johanna Geis-Schroer ◽  
Sebastian Hubschneider ◽  
Lukas Held ◽  
Frederik Gielnik ◽  
Michael Armbruster ◽  
...  
Keyword(s):  
Low Voltage ◽  
Measurement Data ◽  
Analytical Calculation ◽  
Laboratory Measurement ◽  
Model Parameters ◽  
Calculation Methods ◽  
Modeling Approach ◽  
Measurement Results ◽  
Simulation Results ◽  
Return Path

In this contribution, measurement data of phase, neutral, and ground currents from real low voltage (LV) feeders in Germany is presented and analyzed. The data obtained is used to review and evaluate common modeling approaches for LV systems. An alternative modeling approach for detailed cable and ground modeling, which allows for the consideration of typical German LV earthing conditions and asymmetrical cable design, is proposed. Further, analytical calculation methods for model parameters are described and compared to laboratory measurement results of real LV cables. The models are then evaluated in terms of parameter sensitivity and parameter relevance, focusing on the influence of conventionally performed simplifications, such as neglecting house junction cables, shunt admittances, or temperature dependencies. By comparing measurement data from a real LV feeder to simulation results, the proposed modeling approach is validated.

scholarly journals Optimal Calibration of Evaporation Models against Penman–Monteith Equation

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1484
Author(s):  
Dagmar Dlouhá ◽  
Viktor Dubovský ◽  
Lukáš Pospíšil
Keyword(s):  
Model Calibration ◽  
Heat Storage ◽  
Free Water ◽  
Complex Model ◽  
Model Parameters ◽  
Net Radiation ◽  
Statistical Measures ◽  
Pit Lakes ◽  
Evaporation Models ◽  
Monteith Equation

We present an approach for the calibration of simplified evaporation model parameters based on the optimization of parameters against the most complex model for evaporation estimation, i.e., the Penman–Monteith equation. This model computes the evaporation from several input quantities, such as air temperature, wind speed, heat storage, net radiation etc. However, sometimes all these values are not available, therefore we must use simplified models. Our interest in free water surface evaporation is given by the need for ongoing hydric reclamation of the former Ležáky–Most quarry, i.e., the ongoing restoration of the land that has been mined to a natural and economically usable state. For emerging pit lakes, the prediction of evaporation and the level of water plays a crucial role. We examine the methodology on several popular models and standard statistical measures. The presented approach can be applied in a general model calibration process subject to any theoretical or measured evaporation.

Developing a Linearization Method to Determine Optimum Blending for Surimi with Varied Moisture Contents Using Linear Programming

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Hyeon W. Park ◽  
Jae W. Park ◽  
Won B. Yoon
Keyword(s):  
Linear Programming ◽  
Moisture Content ◽  
Standard Procedure ◽  
Unit Cost ◽  
Linearization Method ◽  
Model Parameters ◽  
Additional Information ◽  
Moisture Contents ◽  
Design Variables ◽  
Critical Moisture

AbstractNovel algorithm to determine the least cost formulation of a surimi blend was developed using linear programming (LP). Texture properties and the unit cost of surimi blend at the target moisture content were used as constraint functions and the objective function, respectively. The mathematical models to describe the moisture content dependence of the ring tensile properties were developed using critical moisture content, and the model parameters were used for the least cost LP (LCLP) model. The LCLP model successfully predicted the quality of surimi blend. Sensitivity analysis was used to obtain an additional information when the perturbations of design variables are provided. A standard procedure to determine the least cost formulation for blending surimi with varied moisture contents was systematically developed.

Modelling of the Development of the Vertical Density Profile of MDF during Hot Pressing

2007 ◽  
Vol 2 (2) ◽  
Author(s):  
Arun Gupta ◽  
Patrick Jordan ◽  
Shusheng Pang
Keyword(s):  
Moisture Content ◽  
Density Profile ◽  
Hot Pressing ◽  
Major Influence ◽  
Transfer Model ◽  
Uniform Density ◽  
Moisture Movement ◽  
Vertical Density Profile ◽  
Vertical Density ◽  
Pressing Operation

The hot pressing operation is one of the most important operations in medium density fibreboard (MDF) manufacture. Complicated dynamic interactions occur during pressing, including heat transfer, moisture movement, development of gas pressure, internal stress development and relaxation, wood consolidation, resin curing, bonding between particles and eventual development of a non-uniform density distribution through the panel thickness. Consequently the mat experiences continuously changing internal conditions (temperature and moisture content) as the pressing operation proceeds. The vertical density profile (VDP) has a major influence on the MDF strength and physical properties. This influence of the VDP on the board properties is generally recognised, but the formation of the density profile and their specific effects on the board performance have proved difficult to quantify. A mathematical model based on theoretical analysis and experimental information is being developed. In the model, the mat is divided into a number of thin parallel layers. The deformation of each layer is a function of stress, temperature and moisture content of the layer. The model incorporates the variation of the mat mechanical and rheological properties with moisture content and temperature. The changes in temperature and moisture content are provided by a separate heat and mass transfer model. The present model can predict stress, strain, layer deformation and density across the thickness during pressing. The performance of the model was validated by experiments conducted in a pilot-scale press. Twelve MDF boards were made with different pressing parameters, and the VDP were measured and compared with the simulation results from the model. The model could predict the density profile with an acceptable accuracy for the main variables that control the manufacturing of MDF boards.

Comparison of Crash Test and Simulation Results for Impact of Silverado Pickup into New Jersey Barrier under Manual for assessing Safety Hardware

2012 ◽  
Vol 2309 (1) ◽  
pp. 114-126 ◽  
Author(s):  
Dhafer Marzougui ◽  
Cing-Dao (Steve) Kan ◽  
Kenneth S. Opiela
Keyword(s):  
New Jersey ◽  
Primary Objective ◽  
Crash Test ◽  
Fe Model ◽  
George Washington ◽  
Statistical Measures ◽  
Detailed Simulation ◽  
Analysis Center ◽  
Simulation Results ◽  
Concrete Barrier

The National Crash Analysis Center (NCAC) at the George Washington University simulated the crash of a 2,270-kg Chevrolet Silverado pickup truck into a standard 32-in. New Jersey shape concrete barrier under the requirements of Test 3–11 of the Manual for Assessing Safety Hardware (MASH). The new, detailed finite element (FE) model for the Chevrolet Silverado was used as the surrogate for the MASH 2270P test vehicle. An FE model of the New Jersey barrier was drawn from the array of NCAC hardware models. The primary objective of this analysis was to simulate the crash test conducted to evaluate how this commonly used, NCHRP 350–approved device would perform under the more rigorous MASH crashworthiness criteria. A secondary objective was to use newly developed verification and validation (V&V) procedures to compare the results of the detailed simulation with the results of crash tests undertaken as part of another project. The crash simulation was successfully executed with the detailed Silverado FE model and NCAC models of the New Jersey concrete barrier. Traditional comparisons of the simulation results and the data derived from the crash test suggested that the modeling provided viable results. Further comparisons employing the V&V procedures provided a structured assessment across multiple factors reflected in the phenomena importance ranking table. Statistical measures of the accuracy of the test in comparison with simulation results provided a more robust validation than previous approaches. These comparisons further confirmed that the model was able to replicate impacts with a 2270P vehicle, as required by MASH.

scholarly journals Regionalizing rainfall–runoff model parameters to predict the daily streamflow of ungauged catchments in the dry tropics

2009 ◽  
Vol 40 (5) ◽  
pp. 433-444 ◽  
Author(s):  
David A. Post
Keyword(s):  
Input Data ◽  
Water Yield ◽  
Model Parameters ◽  
Rainfall Runoff ◽  
Wet Season ◽  
Daily Streamflow ◽  
Total Length ◽  
Dry Tropics ◽  
Rainfall Runoff Model ◽  
Runoff Model

A methodology has been derived which allows an estimate to be made of the daily streamflow at any point within the Burdekin catchment in the dry tropics of Australia. The input data requirements are daily rainfall (to drive the rainfall–runoff model) and mean average wet season rainfall, total length of streams, percent cropping and percent forest in the catchment (to regionalize the parameters of the rainfall–runoff model). The method is based on the use of a simple, lumped parameter rainfall–runoff model, IHACRES (Identification of unit Hydrographs And Component flows from Rainfall, Evaporation and Streamflow data). Of the five parameters in the model, three have been set to constants to reflect regional conditions while the other two have been related to physio-climatic attributes of the catchment under consideration. The parameter defining total catchment water yield (c) has been estimated based on the mean average wet season rainfall, while the streamflow recession time constant (τ) has been estimated based on the total length of streams, percent cropping and percent forest in the catchment. These relationships have been shown to be applicable over a range of scales from 68–130,146 km2. However, three separate relationships were required to define c in the three major physiographic regions of the Burdekin: the upper Burdekin, Bowen and Suttor/lower Burdekin. The invariance of the relationships with scale indicates that the dominant processes may be similar across a range of scales. The fact that different relationships were required for each of the three major regions indicates the geographic limitations of this regionalization approach. For most of the 24 gauged catchments within the Burdekin the regionalized rainfall–runoff models were nearly as good as or better than the rainfall–runoff models calibrated to the observed streamflow. In addition, models often performed better over the simulation period than the calibration period. This indicates that future improvements in regionalization should focus on improving the quality of input data and rainfall–runoff model conceptualization rather than on the regionalization procedure per se.

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