Simulation of Basin Scale Runoff Reduction by Infiltration Systems

1994 ◽  
Vol 29 (1-2) ◽  
pp. 267-275 ◽  
Author(s):  
S. Herath ◽  
K. Musiake
Keyword(s):  
Urban Areas ◽  
Infiltration Rate ◽  
System Model ◽  
Richards Equation ◽  
Model Parameters ◽  
Runoff Reduction ◽  
Water Head ◽  
Basin Scale ◽  
Runoff Model ◽  
Modelling Approach

A modelling approach is presented to simulate infiltration systems in urban areas. The model consists of a hydrological sub-model and an infiltration system sub-model. Infiltration characteristics of individual facilities are first established using steady state numerical simulation of Richards' equation. These are represented as linear relations between the facility water head and infiltration rate for given facility widths. The infiltration system model is obtained by applying continuity equation to infiltration facilities lumped over a sub-catchment. This model is then coupled to a catchment runoff model to simulate storm runoff with infiltration systems. The model is applied to an infiltration system installation in a residential area, where stormwater runoff is monitored in a pilot area and a comparative area. The observed results suggest the method is adequate to evaluate the performance of infiltration systems. Except for the catchment storage routing parameter, all model parameters are determined from physical catchment characteristics.

scholarly journals Quantitative analysis of runoff reduction in the Laohahe basin

2012 ◽  
Vol 43 (1-2) ◽  
pp. 38-47 ◽  
Author(s):  
Liliang Ren ◽  
Xiaofan Liu ◽  
Fei Yuan ◽  
Jing Xu ◽  
Wei Liu
Keyword(s):  
Climate Change ◽  
Human Activity ◽  
Hydrological Model ◽  
Model Parameters ◽  
Rainfall Runoff ◽  
Runoff Reduction ◽  
Runoff Series ◽  
Drastic Effect ◽  
Rainfall Runoff Model ◽  
Runoff Model

In order to determine the reason for runoff reduction, daily natural runoff series were restored using a conceptual rainfall–runoff model. The period of 1970–1979 was regarded as a base period with little human activity; model parameters for each subcatchment within the Laohahe basin were calibrated for this period. The effects of human activity and climate change on runoff were quantified by comparing the observed runoff and the natural runoff simulated by the hydrological model. The results show that the observed annual mean runoffs in the 1980s and especially in the 2000s are smaller than those of the 1970s. Although runoff reduction in the 1980s and 2000s is mainly caused by climate change, human activity also plays an important role on the runoff reduction. Taking the 2000 as an example, human activity and climate change are responsible for 45.6 and 54.4% of the runoff reduction in Laohahe basin, respectively. The effect of human activity on runoff reduction in the Laohahe basin is increasingly intensive from the 1980s to the 2000s. Human activity in the Dianzi catchment has the most drastic effect within the Laohahe basin.

scholarly journals Runoff thresholds in derived flood frequency distributions

2008 ◽  
Vol 12 (6) ◽  
pp. 1295-1307 ◽  
Author(s):  
A. Gioia ◽  
V. Iacobellis ◽  
S. Manfreda ◽  
M. Fiorentino
Keyword(s):  
Source Area ◽  
Infiltration Rate ◽  
Flood Frequency ◽  
Model Parameters ◽  
Runoff Generation ◽  
Frequency Model ◽  
Frequency Distributions ◽  
Proposed Model ◽  
Basin Scale ◽  
New Formulation

Abstract. In general, different mechanisms may be identified as responsible of runoff generation during ordinary events or extraordinary events at the basin scale. In a simplified scheme these mechanisms may be represented by different runoff thresholds. In this context, the derived flood frequency model, based on the effect of partial contributing areas on peak flow, proposed by Iacobellis and Fiorentino (2000), was generalized by providing a new formulation of the derived distribution where two runoff components are explicitly considered. The model was tested on a group of basins in Southern Italy characterized by annual maximum flood distributions highly skewed. The application of the proposed model provided good results in terms of descriptive ability. Model parameters were also found to be well correlated with geomorphological basin descriptors. Two different threshold mechanisms, associated respectively to ordinary and extraordinary events, were identified. In fact, we found that ordinary floods are mostly due to rainfall events exceeding a threshold infiltration rate in a small source area, while the so-called outlier events, responsible of the high skewness of flood distributions, are triggered when severe rainfalls exceed a threshold storage in a large portion of the basin.

scholarly journals Sequential modelling of the Earth’s core magnetic field

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Guillaume Ropp ◽  
Vincent Lesur ◽  
Julien Baerenzung ◽  
Matthias Holschneider
Keyword(s):  
Magnetic Field ◽  
Prior Information ◽  
Spatial Scales ◽  
Model Parameters ◽  
International Geomagnetic Reference Field ◽  
The Earth ◽  
Temporal And Spatial ◽  
Different Sources ◽  
Original Approach ◽  
Modelling Approach

Abstract We describe a new, original approach to the modelling of the Earth’s magnetic field. The overall objective of this study is to reliably render fast variations of the core field and its secular variation. This method combines a sequential modelling approach, a Kalman filter, and a correlation-based modelling step. Sources that most significantly contribute to the field measured at the surface of the Earth are modelled. Their separation is based on strong prior information on their spatial and temporal behaviours. We obtain a time series of model distributions which display behaviours similar to those of recent models based on more classic approaches, particularly at large temporal and spatial scales. Interesting new features and periodicities are visible in our models at smaller time and spatial scales. An important aspect of our method is to yield reliable error bars for all model parameters. These errors, however, are only as reliable as the description of the different sources and the prior information used are realistic. Finally, we used a slightly different version of our method to produce candidate models for the thirteenth edition of the International Geomagnetic Reference Field.

Multi-day flow forecasting using the Kalman filter

1991 ◽  
Vol 18 (2) ◽  
pp. 320-327 ◽  
Author(s):  
Murray A. Fitch ◽  
Edward A. McBean
Keyword(s):  
Kalman Filter ◽  
Prediction Model ◽  
Linear Prediction ◽  
Measured Data ◽  
System Model ◽  
Parameter Estimates ◽  
Model Parameters ◽  
Forecasting Performance ◽  
Optimal Forecasting ◽  
Linear Prediction Model

A model is developed for the prediction of river flows resulting from combined snowmelt and precipitation. The model employs a Kalman filter to reflect uncertainty both in the measured data and in the system model parameters. The forecasting algorithm is used to develop multi-day forecasts for the Sturgeon River, Ontario. The algorithm is shown to develop good 1-day and 2-day ahead forecasts, but the linear prediction model is found inadequate for longer-term forecasts. Good initial parameter estimates are shown to be essential for optimal forecasting performance. Key words: Kalman filter, streamflow forecast, multi-day, streamflow, Sturgeon River, MISP algorithm.

Simulation and Simulation Software Development of the Braking Process of a Subway Train

2014 ◽  
Vol 556-562 ◽  
pp. 294-301 ◽  
Author(s):  
Long Han ◽  
Chun Tian ◽  
Yan Wang ◽  
Meng Ling Wu ◽  
Zhuo Jun Luo
Keyword(s):  
Computational Effort ◽  
Simulation Software ◽  
System Model ◽  
Brake System ◽  
Railway Vehicle ◽  
Model Parameters ◽  
Modeling Process ◽  
Time Simulation ◽  
Subway Train ◽  
Braking Process

This paper deals with the problem of braking process modeling. A subway train braking process simulation software is built, which composes of a GUI and a underlying model. The underlying model consists of a train model and a brake system model. The train model is simplified and built by assembling subcomponent element models of a railway vehicle. The brake system model is simplified and built based on experimental data in order to reduce computational effort. The GUI of the software can be use to input model parameters, display simulation results, and store simulation data. As a result of the simplifications of the modeling process, the developed software can perform real time simulation.

Fractal tools to analyse the spatial variability of Blue Green Solutions in an urban area

2021 ◽  
Author(s):  
Gustavo Otranto-da-Silva
Keyword(s):  
Urban Area ◽  
Urban Areas ◽  
Model Performance ◽  
Green Roofs ◽  
Initial State ◽  
Runoff Reduction ◽  
Build Environment ◽  
Input Variables ◽  
Neighborhood Scale ◽  
Design Options

<div> <p><span>A city's response to a rainfall event depends not only on the rainfall spatial-temporal variability, but also on the spatial distribution and the initial state of its Blue Green Solutions (BGS), such as green roofs. They hold back runoff and may prove being critically important elements of blue-green build environment.</span></p> </div><div> <p><span>The aim of this study was first to adapt the existing hydrological model to the urban area of Melun (France), to validate it and then to assess numerically an optimal configuration of green roofs to mitigate pluvial floods for particularly vulnerable areas. </span><span>The main focus was put on the investigation of interactions between rainfall space-time scales and resulting hydrological response over fine scales, all being controlled by the performance assessment of BGS. </span></p> </div><div> <p><span>This presentation will particularly illustrate how fractal </span><span>tools were used to:</span></p> </div><div> <p><span>- highlight the scale dependency of the input variables and its e</span><span>ff</span><span>ects on gridded model performance;</span></p> </div><div> <p><span>- explore, </span><span>analyse</span><span> and represent the influence of BGS location and configuration on the mitigation of runoff associated with short-duration, high-intensity rainfall at neighborhood scale;</span></p> </div><div> <p><span> - identify the urban design options that maximize the potential for runoff reduction</span><span>. </span></p> </div><div> <p><span>In overall, these </span><span>results may serve as a referential </span><span>for upscaling the optimized implementation of BGS in urban areas, by considering other urban infrastructures and their interactions.</span></p> </div>

Using time compression approximation to determine actual infiltration rate from variable rainfall events

2017 ◽  
Vol 50 (1) ◽  
pp. 155-165 ◽  
Author(s):  
Yanyan Cheng ◽  
Guotao Cui ◽  
Jianting Zhu
Keyword(s):  
Infiltration Rate ◽  
Maximum Error ◽  
Richards Equation ◽  
Rainfall Time Series ◽  
Rainfall Events ◽  
Practical Applications ◽  
Time Compression ◽  
Cumulative Infiltration ◽  
Rainfall Patterns ◽  
Numerical Solver

Abstract Understanding infiltration into soils from rainfall events is important for many practical applications. The idea of time compression approximation (TCA) was proposed to simulate infiltration rate, which only requires the relationship between the potential infiltration rate (PIR) and potential cumulative infiltration (PCI). The TCA-based method can be used in any rainfall–runoff models since the PIR vs. PCI relationship can be developed independent of actual rainfall patterns. The main objective of this study is to establish guidelines on when this method can be adequately applied. The results based on the TCA are compared with those from the field observations and the Richards equation numerical solver for observed rainfall events and randomly generated rainfall patterns with prescribed temporal variabilities and hiatuses. For continuous rainfall with potential ponding, the maximum error of infiltration amount using the TCA-based method is less than 5%. The TCA-based method, in general, underestimates the total infiltration amount from variable rainfall events. Variance in rainfall time series does not significantly affect the errors of using the TCA-based method to determine the actual infiltration rate. The TCA-based method can produce reasonable results in simulating the actual infiltration rate for rainfall events with a short hiatus.

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