• 한국농공학회논문집
• /
• 제58권4호
• /
• pp.57-66
• /
• 2016

Harmonized World Soil Database (HWSD) including the global soil information has been implemented to the runoff analysis in many watersheds of the world. However, its accuracy can be a critical issue in the modeling because of the limitation the low resolution reflecting the physical properties of soil in a watershed. Accordingly, this study attempted to assess the effect of HWSD in modeling by comparing parameters of the rainfall-runoff model using HWSD with the detailed soil map. For this, Grid based Rainfall-runoff Model (GRM) was employed in the Hyangseok watershed. The results showed that both of two soil maps in the rainfall-runoff model are able to well capture the observed runoff. However, compared with the detailed soil map, HWSD produced more uncertainty in the GRM parameters related to soil depth and hydraulic conductivity during the calibrations than the detailed soil map. Therefore, the uncertainty from the limited information on soil texture in HWSD should be considered for better calibration of a rainfall-runoff model.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2008년도 학술발표회 논문집
• /
• pp.234-238
• /
• 2008

The energy conservation theory is introduced for investigating processes of runoff and soil erosion on the hillslope system changed vegetation condition by wildfire The rainfall energy, input energy consisted of kinetic and potential energy, is influenced by vegetation coverage and height. Output energy at the outlet of hillslope is decided as the kinetic energy of runoff and erosion soil, and mechanical work according to moving water and soil is influenced dominantly by the work rather than the kinetic energy. Relationship between output and input energy is possible to calculate the energy loss in the runoff and erosion process. The absolute value of the energy loss is controlled by the input energy size of rainfall because energy losses of runoff increase as many rainfall pass through the hillslope system. The energy coefficient which is dimensionless is defined as the ratio of input energy of rainfall to output energy of runoff water and erosion soil such as runoff coefficient. The energy coefficient and runoff coefficient showed the highest correlation coefficient with the vegetation coverage. Maximum energy coefficient is about 0.5 in the hillslope system. The energy theory for output energy of runoff and soil erosion is presented by the energy coefficient theory associated with vegetation factor. Also runoff and erosion soil resulting output energy have the relation of power function and the rates of these increase with rainfall.

• 산업기술연구
• /
• 제30권B호
• /
• pp.99-108
• /
• 2010

This study was intended to estimate the soil runoff at the basin of Mandaechun where the measure needs to be taken to deal with the increasing muddy water resulting from soil runoff during wet season and torrential rain at the high reaches of the Soyang lake where highland vegetables are cultivated and soil replacement for improvement is carried out every two to three years. The study was carried out in such a way of identifying the topographic factors using geographical spatial data from Water Management Information System (WAMIS) and ARC-VIEW program and estimating the soil runoff by rainfall frequency using Revised Universal Soil Loss Equation (RUSLE), and furthermore, evaluating the soil runoff contribution at the basin of Mandaechun based on estimate of the soil runoff by section.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2011년도 학술발표회
• /
• pp.188-193
• /
• 2011

This study was intended to estimate the soil runoff at the basin of Mandaechun where the measure needs to be taken to deal with the increasing muddy water resulting from soil runoff during wet season and torrential rain at the high reaches of the Soyang lake where highland vegetables are cultivated and soil replacement for improvement is carried out every two to three years. The study was carried out in such a way of identifying the topographic factors using geographical spatial data from Water Management Information System (WAMIS) and ARC-VIEW program and estimating the soil runoff by rainfall frequency using Revised Universal Soil Loss Equation (RUSLE), and furthermore, evaluating the soil runoff contribution at the basin of Mandaechun based on estimate of the soil runoff by section.

• Water Engineering Research
• /
• 제5권2호
• /
• pp.55-68
• /
• 2004

The GLEAMS (Groundwater Loading Effects of Agricultural Management System, version 3.0) water quality model was used to predict hydrology and water quality and to evaluate the effects of soil types from a cattle-grazed pasture field of Bermuda-Rye grass rotation with poultry litter application as a fertilizer in North Alabama. The model was applied and evaluated by using four years (1999-2002) of field-measured data to compare the simulated results for the 2.71- ha Summerford watershed. $R^2$ values between observed and simulated runoff, sediment yields, TN, and TP were 0.91, 0.86, 0.95, and 0.69, respectively. EI (Efficiency Index) of these parameters were 0.86, 0.67, 0.70, and 0.48, respectively. The statistical parameters indicated that GLEAMS provided a reasonable estimation of the runoff, sediment yield, and nutrient losses at the studied watershed. The soil infiltration rates were compared with the rainfall events. Only high intensity rainfall events generated runoff from the watershed. The measured and predicted infiltration rates were higher during dry soil conditions than wet soil conditions. The ratio of runoff to precipitation was ranging from 2.2% to 8.8% with average of 4.3%. This shows that the project site had high infiltration and evapotranspiration which generated the low runoff. The ratio of runoff to precipitation according to soil types by the GLEAMS model appeared that Sa (Sequatchie fine sandy loam) soil type was higher and Wc (Waynesboro fine sandy loam, severely eroded rolling phase) soil type relatively lower than the weighted average of the soil types in the watershed. The model under-predicted runoff, sediment yields, TN, and TP in Wb (Waynesboro fine sandy loam, eroded undulating phase) and Wc soil types. General tendency of the predicted data was similar for all soil types. The model predicted the highest runoff in Sa soil type by 105% of the weighted average and the lowest runoff in Wc soil type by 87% of the weighted average

• 한국환경복원기술학회지
• /
• 제18권3호
• /
• pp.13-22
• /
• 2015

Unpaved forest roads are common accessways in mountain areas being used for forestry purposes. The presence of forest roads produces large volumes of surface runoff and sediment yield due to changes in soil properties and hillslope profile. Rainfall simulation experiments were conducted to estimate the impacts of above-ground vegetation and antecedent soil water condition on hydrology and sediment processes. A total of 9 small plots($1m{\times}0.5m$) were installed to represent different road surface conditions: no-vegetation(3 plots), vegetated surface(3 plots), and cleared vegetation surface(3 plots). Experiments were carried out on dry, wet, and very wet soil moisture conditions for each plot. Above ground parts of vegetation on road surface influenced significantly on surface runoff. Runoff from no-vegetation roads(39.24L) was greater than that from vegetated(25.05L), while cleared-vegetation condition is similar to no-vegetation roads(39.72L). Runoff rate responded in a similar way to runoff volume. Soil erosion was also controlled by land cover, but the magnitude is little than that of surface runoff. Even though slight differences among antecedent soil moisture conditions were found on both runoff and soil erosion, runoff rate and soil losses were increased in very wet condition, followed by wet condition. The experiments suggest that vegetation cover on forest road surface seems most effective way to reduce surface runoff and soil erosion during storm periods.

• 한국토양비료학회지
• /
• 제46권6호
• /
• pp.417-425
• /
• 2013

This study investigated the runoff from rice paddy located on reclaimed fine sandy loam soil to provide data for the development of policies to protect water quality of estuaries. Total N (TN), Total P (TP) concentrations and runoff loads at outlet were monitored from 2006 to 2008. Soil phosphate adsorptivity was measured and compared with typical paddy soil in watersheds. TP concentration of the paddy water and TP runoff loads were much greater than those of typical paddy field in watershed because phosphate adsoptivity in reclaimed paddy field of fine sandy loam appeared to be a third of those of typical paddy soils by relatively low soil OM and high sand content of the reclaimed soil. Thus, nutrient runoff, particularly phosphate from the reclaimed paddy field needs to be managed more thoroughly to protect estuarine water quality.

• 한국습지학회지
• /
• 제25권2호
• /
• pp.121-131
• /
• 2023

본 연구에서는 토심 대신 유효토심을 사용함에 따라 발생하는 강우-유출 해석과정의 문제를 VIC(Variable Infiltration Capacity) 모형을 가지고 살펴보았다. 이러한 연구목적을 달성하기 위해 모형의 매개변수를 다음과 같이 결정하였다. 먼저, 가용한 수치 정보를 이용하여 결정할 수 있는 매개변수는 고정하였다. 직접유출 및 기저유출 등에 관여하는 매개변수는 VIC 모형의 추천값을 적용하였다. 토심의 경우 (1) 유효토심을 적용하는 경우, (2) 토양층 연직 구조 특성을 반영하여 유효토심의 1.5배를 적용하는 경우 및 (3) 유효토심의 1.25배를 가정한 토심을 적용하는 경우, (4) 유효토심의 2.0배를 가정한 토심을 적용하는 경우 총 4가지를 고려하였다. 본 연구는 한강 유역의 충주댐 유역 및 소양강댐 유역을 대상으로 1983년에서 2020년까지의 기간에 대해 모의를 수행하였다. 연구 결과, 토심 대신 유효 토심을 적용하는 경우 직접유출과 기저유출에는 정반대의 영향을 미치며, 직접유출에는 3% 이상의 증가, 기저유출에는 동일 규모의 감소가 발생하는 것을 확인하였다. 추가로 충주댐과 소양강댐 유역의 유효토심 추정에 있어 가장 큰 영향을 미치는 것은 암석노출지의 비중으로 나타났으며, 그 영향으로 두 유역의 직접유출률과 기저유출률의 차이가 크게 다른 것으로 확인할 수 있었다.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 1998년도 학술발표회 발표논문집
• /
• pp.521-526
• /
• 1998

This study was initiated to build runoff plots, install soil and water quality monitoring systems and collect background data from the plots and soils to assess runoff the nonpoint source pollution and soil physical change in mountainous soils. Eleven 3 $\times$ 15 m runoff plots and monitoring systems were installed at a field of National Alpine Agricultural Experiment Station to monitor soil physical change, and discharge of nonpoint source pollutant. Corn and potato were cultivated under different fertilizer, tillage and residue cover treatments. The soil has a single-layered cluster structure that has a relatively good hydrologic properties and can adsorb a large amount of nutrient. 11 runoff plots were treated and monitored with respect to physical property of the soil, runoff and sediment discharge.

• 한국수자원학회논문집
• /
• 제52권9호
• /
• pp.615-626
• /
• 2019

토양수분과 유출은 매우 밀접한 관계를 가지고 있으며, 특히 토양 내의 여러 요소들에 의해 토양의 수분보유능력과 배수의 특성이 결정된다. 본 연구에서는 2016년, 2017년 설마천 유역에서 총 40개의 사상을 분리하였다. 선정한 사상별로 constant-K 방법을 적용하여 직접유출과 기저유출을 분리하고 유출계수를 산정하였다. 산정된 유출계수는 선행토양함수와 지수함수 형태의 증가를 보였다. 또한 유출계수가 급증하기 시작하는 토양수분의 임계값을 선정하였으며, 이 값은 유출과 지하수면과의 큰 상관관계를 나타내었다. 선행토양함수뿐만 아니라 초기 토양수분, 토양 저류량, 강우량 등 여러 인자들도 유출 결과에 영향을 미치는 것으로 분석되었다. 또한 선행토양수분의 임계값에 따라 강우사상을 건조, 습윤 상태로 분리하여 시작 반응과 첨두 반응을 분석해 보았으며, 습윤 상태에서의 반응이 건조 상태에서 보다 빠르게 발생하였다. 건조 상태에 속하는 대부분의 사상에서는 토양수분이 정점에 도달한 후 지하수면과 유출량 순으로 정점에 도달하는 첨두 반응이 일어났으나 습윤 상태에서는 반대로 지하수면과 유출량이 토양수분보다 먼저 정점에 도달하였다. 본 연구의 결과는 유출에 기여하는 인자들 사이의 상호작용을 확인하고 토양의 다양한 조건과 유출 사이의 관계를 규명하는 데에 크게 기여할 것으로 판단된다.