• Title/Summary/Keyword: Distributed Runoff Modeling

Search Result 49, Processing Time 0.023 seconds

Grid Network Analysis for Distributed Rainfall-Runoff Modelling (분포형 강우-유출 모의를 위한 격자 네트워크 해석)

  • Choi, Yun-Seok;Lee, Jin-Hee;Kim, Kyung-Tak
    • Journal of Korea Water Resources Association
    • /
    • v.41 no.11
    • /
    • pp.1123-1133
    • /
    • 2008
  • It needs to conceptualize watershed with triangular or rectangular elements and to analyze the changes in hydrological components of each element for distributed modeling of rainfall-runoff process. This study is the network analysis of watershed grid for flow routing occurred in each element when analyzing rainfall-runoff process by one-dimensional kinematic wave equation. Single flow direction from D8-method(deterministic eight-neighbors method) is used, and the information of flow direction and flow accumulation are used to determine the computation order of each element. The application theory of finite volume method is suggested for each flow direction pattern between elements, and it is applied it to calculate the flow of each grid. Network analysis method from this study is applied to GRM(Grid based Rainfall-runoff Model) which is physically based distributed rainfall-runoff model, and the results from simplified hypothetical watersheds are compared with $Vflo^{TM}$ to examine the reasonability of the method. It is applied to Jungrangcheon watershed in Han river for verification, and examination of the applicability to real site. The results from Jungrangcheon watershed show good agreement with measured hydrographs, and the application of the network analysis method to real site is proper.

Application of a Distributed Model for Evaluating the Effect of Sacheonman Spillway on the Flood Reduction in the Downstream of Namgang Dam (사천만 방수로가 남강댐 하류의 홍수량 저감에 미치는 영향 평가를 위한 분포형 모형의 적용)

  • Choi, Cheon Kyu;Choi, Yun Seok;Kim, Kyung Tak
    • Journal of Wetlands Research
    • /
    • v.14 no.3
    • /
    • pp.399-411
    • /
    • 2012
  • Namgang Dam is located in the upstream of Nam river. Namgang Dam controls flood for the downstream of Namgang Dam using the Namgang spillway and the Sacheonman spillway with planned discharge. However, it had not been evaluated adequately that the effect of the discharge through Sacheonman spillway on the flood reduction of the downstream of Namgang Dam. This study performs runoff simulation considering the discharge from Namgang Dam and Sacheonman spillway. And modeling results are evaluated for the flood reduction effect of Sacheonman spillway on the downstream of Namgang Dam. This study uses a distributed model, GRM(Grid based Rainfall-runoff Model) for runoff analysis. As a result, Sacheonman spillway is assigned more discharge than Namgang Dam, and Sacheonman spillway greatly affects flood reduction in the downstream of Namgang Dam.

HSPF Modeling for Identifying Runoff Reduction Effect of Nonpoint Source Pollution by Rice Straw Mulching on Upland Crops (볏짚 피복에 의한 밭 비점원오염 저감효과 분석을 위한 HSPF 모델링)

  • Jung, Chung-Gil;Park, Jong-Yoon;Lee, Hyung-Jin;Choi, Joong-Dae;Kim, Seong-Joon
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.54 no.4
    • /
    • pp.1-8
    • /
    • 2012
  • This study is to assess the reduction of non-point source pollution loads for rice straw surface covering of upland crop cultivation at a watershed scale. For Byulmi-cheon watershed ($1.21km^2$) located in the upstream of Gyeongancheon, the HSPF (Hydrological Simulation Program-Fortran), a physically based distributed hydrological model was applied. Before evaluation, the model was calibrated and validated using 9 rainfall events. The Nash-Sutcliffe model efficiency (NSE) for streamflow was 0.62~0.78 and the NSE for water quality (Sediment, T-N, and T-P) were 0.68, 0.60, and 0.58 respectively. From the field experiment of 16 rainfall events, the rice straw covering reduced surface runoff average 10 % compared to normal surface condition. By handling infiltration parameter (INFILT) in the model, the value of 16.0 mm/hr was found to reduce about 10 % reduction of surface runoff. For this condition, the reduction effect of Sediment, T-N, and T-P loads were 87.2, 28.5, and 85.1 % respectively. The rice straw surface covering was effective for removing surface runoff dependent loads such as Sediment and T-P.

Development of Distributed Rainfall -Runoff Model by Using GIS and Uncertainty Analysis (II) - Application and Analysis - (GIS와 불확실도 해석기법을 이용한 분포형 강우 -유출 모형의 개발 (II) - 적용 및 분석 -)

  • Choi, Hyun-Sang;Han, Kun-Yeun
    • Journal of Korea Water Resources Association
    • /
    • v.37 no.4
    • /
    • pp.341-352
    • /
    • 2004
  • In this study(II), the model developed in the previous study(I) has been tested on two cases of constant-slope areas to verify the model applicability. Firstly, an impervious one-dimensional runoff problem has been simulated. Secondly, an impervious two-dimensional runoff problem at a converging plain which consists of a V-shaped section plus a portion of the surface of a cone has been simulated. For each case, the simulation results have good agreements with the observed data. And the model has been applied to actual watersheds, which were the Sulma watershed with 8$\textrm{km}^2$ and the Donggok watershed with 33.2$\textrm{km}^2$, drainage area, respectively. The simulated results agree with observed in terms of discharges at several stations. Monte Carlo simulation was also performed on the same watersheds and the modeling results have been evaluated. The suggested model can be used for real-time forecasting of rainfall-runoff analysis, and will contribute for basinwide flood control in the future.

Development and Application of a Physics-based Soil Erosion Model (물리적 표토침식모형의 개발과 적용)

  • Yu, Wansik;Park, Junku;Yang, JaeE;Lim, Kyoung Jae;Kim, Sung Chul;Park, Youn Shik;Hwang, Sangil;Lee, Giha
    • Journal of Soil and Groundwater Environment
    • /
    • v.22 no.6
    • /
    • pp.66-73
    • /
    • 2017
  • Empirical erosion models like Universal Soil Loss Equation (USLE) models have been widely used to make spatially distributed soil erosion vulnerability maps. Even if the models detect vulnerable sites relatively well utilizing big data related to climate, geography, geology, land use, etc within study domains, they do not adequately describe the physical process of soil erosion on the ground surface caused by rainfall or overland flow. In other words, such models are still powerful tools to distinguish the erosion-prone areas at large scale, but physics-based models are necessary to better analyze soil erosion and deposition as well as the eroded particle transport. In this study a physics-based soil erosion modeling system was developed to produce both runoff and sediment yield time series at watershed scale and reflect them in the erosion and deposition maps. The developed modeling system consists of 3 sub-systems: rainfall pre-processor, geography pre-processor, and main modeling processor. For modeling system validation, we applied the system for various erosion cases, in particular, rainfall-runoff-sediment yield simulation and estimation of probable maximum sediment (PMS) correlated with probable maximum rainfall (PMP). The system provided acceptable performances of both applications.

Assessment of Rainfall-Sediment Yield-Runoff Prediction Uncertainty Using a Multi-objective Optimization Method (다중최적화기법을 이용한 강우-유사-유출 예측 불확실성 평가)

  • Lee, Gi-Ha;Yu, Wan-Sik;Jung, Kwan-Sue;Cho, Bok-Hwan
    • Journal of Korea Water Resources Association
    • /
    • v.43 no.12
    • /
    • pp.1011-1027
    • /
    • 2010
  • In hydrologic modeling, prediction uncertainty generally stems from various uncertainty sources associated with model structure, data, and parameters, etc. This study aims to assess the parameter uncertainty effect on hydrologic prediction results. For this objective, a distributed rainfall-sediment yield-runoff model, which consists of rainfall-runoff module for simulation of surface and subsurface flows and sediment yield module based on unit stream power theory, was applied to the mesoscale mountainous area (Cheoncheon catchment; 289.9 $km^2$). For parameter uncertainty evaluation, the model was calibrated by a multi-objective optimization algorithm (MOSCEM) with two different objective functions (RMSE and HMLE) and Pareto optimal solutions of each case were then estimated. In Case I, the rainfall-runoff module was calibrated to investigate the effect of parameter uncertainty on hydrograph reproduction whereas in Case II, sediment yield module was calibrated to show the propagation of parameter uncertainty into sedigraph estimation. Additionally, in Case III, all parameters of both modules were simultaneously calibrated in order to take account of prediction uncertainty in rainfall-sediment yield-runoff modeling. The results showed that hydrograph prediction uncertainty of Case I was observed over the low-flow periods while the sedigraph of high-flow periods was sensitive to uncertainty of the sediment yield module parameters in Case II. In Case III, prediction uncertainty ranges of both hydrograph and sedigraph were larger than the other cases. Furthermore, prediction uncertainty in terms of spatial distribution of erosion and deposition drastically varied with the applied model parameters for all cases.

A Study on the Effectiveness of Radar Rainfall by Comparing with Flood Inundation Record Map Using KIMSTORM (Grid-based KIneMatic Wave STOrm Runoff Model) (분포형 강우유출모형 KIMSTORM을 이용한 침수실적자료와의 비교를 통한 레이더강우의 효용성 연구)

  • Ahn, So Ra;Jung, Chung Gil;Kim, Seong Joon
    • Journal of Korea Water Resources Association
    • /
    • v.48 no.11
    • /
    • pp.925-936
    • /
    • 2015
  • The purpose of this study is to explore the effectiveness of dual-polarization radar rainfall by comapring with the flood inundation record map through KIMSTORM(Grid-based KIneMatic wave STOrm Runoff Model). For Namgang dam ($2,293km^2$) watershed, the Bisl dual-polarization radar data for 3 typhoons (Khanun, Bolaven, Sanba) and 1 heavy rain event in 2012 were prepared. For both 28 ground rainfall data and radar rainfall data, the model was calibrated using observed discharge data at 5 stations with $R^2$, Nash and Sutcliffe Model Efficiency (ME) and Volume Conservation Index (VCI). The calibration results of $R^2$, ME and VCI were 0.85, 0.78 and 1.09 for ground rainfall and 0.85, 0.79, and 1.04 for radar rainfall respectively. The flood inundation record areas (SY and MD/SG district) by typhoon Sanba were compared with the distributed modeling results. The spatial distribution by radar rainfall produced more surface runoff from the watershed and simulated higher stream discharge than the ground rainfall condition in both SY and MD/SG district. In case of MD/SG district, the stream water level by radar rainfall near the flood inundation area showed 0.72 m higher than the water level by ground rainfall.

Grid Based Nonpoint Source Pollution Load Modelling

  • Niaraki, Abolghasem Sadeghi;Park, Jae-Min;Kim, Kye-Hyun;Lee, Chul-Yong
    • 한국공간정보시스템학회:학술대회논문집
    • /
    • 2007.06a
    • /
    • pp.246-251
    • /
    • 2007
  • The purpose of this study is to develop a grid based model for calculating the critical nonpoint source (NPS) pollution load (BOD, TN, TP) in Nak-dong area in South Korea. In the last two decades, NPS pollution has become a topic for research that resulted in the development of numerous modeling techniques. Watershed researchers need to be able to emphasis on the characterization of water quality, including NPS pollution loads estimates. Geographic Information System (GIS) has been designed for the assessment of NPS pollution in a watershed. It uses different data such as DEM, precipitation, stream network, discharge, and land use data sets and utilizes a grid representation of a watershed for the approximation of average annual pollution loads and concentrations. The difficulty in traditional NPS modeling is the problem of identifying sources and quantifying the loads. This research is intended to investigate the correlation of NPS pollution concentrations with land uses in a watershed by calculating Expected Mean Concentrations (EMC). This work was accomplished using a grid based modelling technique that encompasses three stages. The first step includes estimating runoff grid by means of the precipitation grid and runoff coefficient. The second step is deriving the gird based model for calculating NPS pollution loads. The last step is validating the gird based model with traditional pollution loads calculation by applying statistical t-test method. The results on real data, illustrate the merits of the grid based modelling approach. Therefore, this model investigates a method of estimating and simulating point loads along with the spatially distributed NPS pollution loads. The pollutant concentration from local runoff is supposed to be directly related to land use in the region and is not considered to vary from event to event or within areas of similar land uses. By consideration of this point, it is anticipated that a single mean estimated pollutant concentration is assigned to all land uses rather than taking into account unique concentrations for different soil types, crops, and so on.

  • PDF

Long-term runoff characteristics on HRU variations of PRMS (PRMS의 HRU크기에 따른 장기유출특성)

  • Kim, Nam-Won;Kim, Hyeon-Jun;Park, Sun-Ho
    • Journal of Korea Water Resources Association
    • /
    • v.38 no.2
    • /
    • pp.167-177
    • /
    • 2005
  • In this study, the PRMS(Precipitation and Runoff Modeling System), developed by USGS(United States Geological Survey), was applied to the Yongdam dam watershed in the Geum River basin. The efficiency for runoff simulation and spatial characteristics of PRMS were evaluated. The runoff changes with the changes of subcatchments and HRUs were estimated. As results, the size of the subcatchment and HRV did not significantly affect the runoff at the exit of watershed. Consequently, the spatial characteristic of PRMS was shown as lumped type rather than semi-distributed. The geographical input data for Yongdam dam watershed were converted to the USGS Input type, and the parameters were calibrated using Rosenbrock optimization method, validated with the observed runoff data. The PRMS showed resonable agreements in the long-term continuous runoff simulation, if the accuracy of observed data is ensured.

GIS based Non-Point Source Pollution Assessment

  • Sadeghi-Niaraki, Abolghasem;Kim, Kye-Hyun;Lee, Chol-Young
    • Proceedings of the KSRS Conference
    • /
    • 2008.10a
    • /
    • pp.437-440
    • /
    • 2008
  • In recent years, pollution load calculation has become a topic for research that resulted in the development of numerous GIS modeling methods. The existing pollution method for nonpoint source (NPS) can not be indentified and calculated the amount of the pollution precisely. This research shows that the association of typical pollutant concentrations with land uses in a watershed can provide a reasonably accurate characterization of nonpoint source pollution in the watershed using Expected Mean Concentrations (EMC). The GIS based pollution assessment method is performed for three pollutant constituents: BOD, TN, and TP. First, the runoff grid by means of the precipitation grid and runoff coefficient is estimated. Then, the NPS pollution loads are calculated by grid based method. Finally, the final outputs are evaluated by statistical technique. The results illustrate the merits of the approach. This model verified that GIS based method of estimating spatially distributed NPS pollution loads can lead to more accurate representation of the real world.

  • PDF