• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.1040-1048
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• 2010

An infiltration storage can be installed as a method of reducing runoff from catchment and increasing stream flow during the dry period by recharging groundwater. However, there is no proper model and method that can be used to design storage capacity of an infiltration storage in Korea. The purpose of the study is to evaluate capacities of infiltration storages planned on Jeju-do in Korea by modifying Storm Water Management Model (SWMM). The basic equations for the infiltration storage are same as those of the infiltration trench used in MIDUSS. Infiltration rates of the infiltration storages were first measured by double ring infiltrometers, and then the modified model was applied to evaluate adequacy for the capacities of three infiltration storages planned on Jeju-do in Korea. The application results show that the two infiltration storages with higher infiltration rates have adequate capacities to infiltrate the total water inflow to the storages. However, the other infiltration storage with lower infiltration rates has not sufficient capacity to infiltrate the total water inflow to the storage and release occurs to the downstream region. The simulation model and method applied can be used for capacity evaluation of future infiltration storages on highly pervious areas in Jeju-do.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.1
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• pp.57-65
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• 2007

In Korea, most landslides occurr during the rainy season and have shallow failure planes parallel to the slope. For these types of rainfall-induced failures, the most important factor triggering slope unstability is decrease in the matric suction of unsaturated soils with increasing saturation depth by rainfall infiltration. For this reason, estimation of cumulative infiltration has a significance. In this study, infiltration rate and cumulative infiltration are estimated by using both Mein & Larson model based on Green-Ampt infiltration model and using modified Mein & Larson model to which unsteady rainfall is applied. According to the results, the modified model is more reasonable than Mein & Larson method itself in estimation of infiltration rate and saturation depth because of considering real pending condition.

• Journal of Korea Water Resources Association
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• v.35 no.3
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• pp.285-294
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• 2002

Infiltration is one of the important processes of the hydrologic cycle determining the distribution of water and has been studied extensively. Various theories and models proposed for this process are usually applicable only when the rainfall intensity is higher than the infiltration capacity. The study by Diskin and Nazimov (1995, 1996) suggested a conceptual infiltration model that comprises two elements. The model can make an reasonable approach to the infiltration process, instead of representing the infiltration as a function of time. The study presented herein improved the existing conceptual infiltration model by an additional consideration of the initial moisture contents. The analysis results for the variation of the infiltration capacity curries for various initial moisture contents demonstrate that the model is more reasonable for the approach to the infiltration process. In addition, the results for the relationship of stormwater events-ponding time are compared with the literature values of that for a number of soil types. The agreement is rather good, leading to the conclusion that the improved model is vapid for describing the infiltration process.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.107-111
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• 2009

The parameters in the Horton's model which has well known as typical infiltration model were determined by the use of the optimization technique. It was assumed the initial infiltration capacity in this model was related to the antecedent precipitation per 10 days with linear combination. And both the parameters of the ultimate infiltration capacity and the decay factor were determined uniquely on a basin. Thus the optimal model's parameters representative to a basin were obtained and the Horton's infiltration equations by rainstorm events were determined. The data of ten rainstorm events for this study were observed at the Jeonjeokbigyo station located at the Selmacheon experimental basin that was $8.5\;km^2$ wide in the Imjin river.

• Journal of Korea Water Resources Association
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• v.32 no.3
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• pp.301-310
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• 1999

In this paper a numerical model and two analytical models in the hydraulically connected stream-aquifer system were analyzed to compare the induced infiltration rate curves derived from each model. And we also examined the effects of anisotropy of hydraulic conductivity and the direction of the ambient ground water flow on the quantification of the induced infiltration rate. The induced infiltration rate curve determined by models is very simple and useful for estimating the induced infiltration rate since it contains only four physical variables such as the induced infiltration rate, the pumping rate, the distance between the pumping well and the stream, and the ambient ground water flow rate. Under the conditions tested in this paper the induced infiltration rate curves resulted from the Wilson's analytical model and FEWA numerical model were in good agreement, and the anisotropic ratio of hydraulic conductivity was evaluated as a physical factor which influences the behaviour of the induced infiltration rate curve. The methods and results of the paper might Icad to improve the understanding of the induced infiltration phenomenon and can be applied to the planning and disign of pumping well and the optimal determination of the induced infiltration rate and pumping rate for water quality management of the water supply wells.

• Journal of Soil and Groundwater Environment
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• v.16 no.6
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• pp.27-33
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• 2011

Infiltration plays an important role in the urban water cycle. Infiltration has a potential to contribute to groundwater recharge in addition to runoff reduction. However, infiltration in urban areas has been considered only as a means of runoff reduction. Conventional design methods for infiltration facilities assume soils to be fully-saturated for the sake of simplicity. The amount of groundwater recharge can not be estimated properly with this scheme. Hence, the characteristics of the unsaturated soil condition need to be considered. The finite element model using SEEP/W to estimate infiltration under the unsaturated condition is presented. Infiltration tests for Joomonjin sand are performed and the infiltration behavior of Joomoonjin sand under the unsaturated condition is measured experimentally to verify the validity of the finite element model. The results from comparing infiltrated volume between the saturated and the unsaturated conditions under the same soil and rainfall conditions show that the infiltrated volume in the unsaturated condition is two times bigger than that in the saturated condition.

• Journal of Korea Water Resources Association
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• v.43 no.6
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• pp.533-541
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• 2010

It is basic for a flood prediction to calculate direct runoff from rainfall in a basin by the rainfall-runoff model. The direct runoff is calculated from rainfall excess or effective rainfall based on a rainfall-runoff model. The total rainfall minus rainfall loss equals rainfall excess with time. This loss can be treated equal to an infiltration loss under the assumption that the infiltration is a major one among the losses in the rainfall-runoff model. Practically obtaining the infiltration loss $\Phi$ index method, W index method or modified ones of these have been used. In this study it is assumed the loss of rainfall in a basin be a well-known Horton infiltration mechanism. And in case that the parameter set is given in the Horton infiltration model a procedure and assumption for calculating hourly infiltration loss and rainfall excess are offered and the results of its application are compared with those of $\Phi$ index method. By this study it is well shown the value of Horton infiltration function is exponentially decay with time as the Horton infiltration mechanism.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.74-77
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• 2000

Infiltration and water flow in the upper soil layer of a deep water table aquifer are modeled for multistorm runoff events. The infiltration process is developed using the sharp wetting front model of Green and Ampt, and the following redistribution process is modeled using the gravity drained rectangular approximation. The Brooks-Corey model [Brooks and Corey, 1966] is adopted to relate the effective soil saturation, the tension head, and the unsaturated hydraulic conductivity Firstly, the infiltration and redistribution model is developed for a single stom runoff event. Then a couple of events combined for multistorm runoff events. In the later case, infiltration rate of the second rainfall is strongly influenced by the length of the rainfall hiatus and soil moisture profile.

• Magazine of the Korean Society of Agricultural Engineers
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• v.24 no.1
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• pp.63-72
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• 1982

To maintain an optimum condition for the plant growth on upland soil, the irrigation planning after the natural rainfall should be given enormous considerations on the rainfall effectiveness. This study has been intended to develop the computer model for estimating the effec- tiveness of the rainfall. The computer model should also estimated the infiltration due to the rainfall and the soil moisture deficiency at the root zone of the plant. For this purpose, the experiments of infiltration using rainfall simulator and the observations of the change of soil moisture content before and after rainfall were carried out. Needed input data for the developed model include final infiltration capacity and field capacity of the soil, porosity of the top soil, root depth of the plant, rainfall intensity and duration, and the Horton's decay coefficient. Among the needed input data for the developed model, final infiltration capacity and Horton's decay coefficient were determined by the experiments of infiltration. And from the result of the experiments, it is found that there is a great correlation between initial infiltration capacity and initial moisture content. And it is also found that the infiltration due to rainfall can be estimated with the Horton's equation. The developed model was tested by the experimental data with two rainfall intensities. Tests were conducted on the different root depths at each rainfall. Observed and estimated effective rainfalls were found to have great correlation. The result of the experiments showed that the effectiveness of the rainfall were 100%, so the comparisons were conducted by the comsumption rates of infiltration at each depth. The developed model can be also used for estimating the deficiency of rainfall, if the rainfall is not sufficient to the needed soil moisture. But, test was not carried out.

• Journal of Korea Water Resources Association
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• v.39 no.11 s.172
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• pp.977-984
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• 2006

The parameters in the Horton's model which has well known as typical infiltration model were determined by the use of the optimization technique. It was assumed the initial infiltration capacity in this model was related to the antecedent precipitation per 10 days with linear combination. And both the parameters of the ultimate infiltration capacity and the decay factor were determined uniquely on a basin. Thus the optimal model's parameters representative to a basin were obtained and the Horton's infiltration equations by rainstorm events were determined. The data of ten rainstorm events for this study were observed at the Jeonjeokbigyo station located at the Selmacheon experimental basin that was $8.5km^2$ wide in the Imjin river.