• 한국농공학회:학술대회논문집
• /
• 한국농공학회 1998년도 학술발표회 발표논문집
• /
• pp.370-375
• /
• 1998

The objectives of this study are to evaluate the applicability of SCS TR-20 model for small ungauged watershed, to show the behavior of the model with variation of topography in watershed, and to evaluate the storage effect of paddy field for flood flow. For this purpose, simulated data from the model were compared with the observed flood data at two sites (HS#3, HS#4) in Balan watershed. From the comparison between simulated and observed data, it was found that the model is applicable to this watershed.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 2001년도 학술발표회 발표논문집
• /
• pp.300-305
• /
• 2001

The objectives of the thesis are to estimate flood using critical storm duration. The hydrological models were tested with field data from two small watersheds. The hydrological parameters were defined using the GIS system. And the results from different peak runoff equations and hydrologic models were found to simulate runoff hydrographs that are comparative to the observed.

• 한국농공학회논문집
• /
• 제46권5호
• /
• pp.107-116
• /
• 2004

A GIS-based paddy inundation simulation system which is capable of simulating temporal and spatial inundation processes was established and applied in this paper. The system is composed of HEC-GeoHMS, and HEC-GeoRAS modules which interface the GIS and flood runoff models, and HEC-HMS, and HEC-RAS models which estimate the flood runoff. It was used to simulate storm runoff and inundation for a small rural watershed, the Baran HP#7, which is 10.69 $km^2$ in size. The simulated peak runoff, time to peak, and total direct runoff for eight storms were compared with the observed data. The results showed that the coefficient of determination ($R^2$) for the observed peak runoff was 0.99 and an error, RMSE, 11.862 $m^3$/s for calibration stages. In the model verification, $R^2$ was 0.99 and RMSE 1.296 $m^3$/s. Paddy inundation for each paddy growing stages in study watershed were estimated using verified inundation simulation system when probability rainfall was applied.

• Spatial Information Research
• /
• 제14권1호
• /
• pp.15-27
• /
• 2006

본 연구는 지형학적 단위도(geomorphoclimatic unit hydrograph, GIUH)로 미계측 소유역의 한계유출량을 산정에 관한 연구이다. GIUH는 수문특성예측에 많이 이용된다. 연구대상지역인 경북 감포지역에 대한 $5km^2$의 소유역으로 수문특성인자, 제방월류유량 및 합성단위도(Clark Nakayasu, S.C.S)에 의한 유출량도 함께 분석하였다. 그리고 지리정보시스템으로 지형인자를 추출하고 지형학적순간단위도에서 산정된 첨두유량을 감포지점의 실측자료와 비교함으로써 지형학적순간단위도의 타당성을 검증하였고, 이와 NRCS(Natural Resources Conservation Service)방법을 이용하여 돌발홍수 기준우량을 제시하기위한 한계유출량을 산정하였다.

• 한국수자원학회논문집
• /
• 제33권6호
• /
• pp.745-755
• /
• 2000

현재 우리나라에서 홍수조절 업무에 황용하고 있는 홍수관리시스템은 댐에서 조절이 불가능한 댐하류부 수문현상들을 고려하여 방류계획을 수립할 수 없으며, 예측 강우량에 의한 댐으로의 유출상황을 고려한 예비방류에 관한 지침이 마련되어 있지 않다. 따라서 본 연구에서는 댐의 제약조건 댐 상.하류의 유출상황을 고려하여 홍수기 댐을 운영 할 수 있는 모의기법에 의한 모형을 개발하였다. 개발된 모형(EV ROM이라 명명)은 댐에서 조절이 불가능한 댐하류 지류에 의한 하류 홍수제어 지점의 Cumulative Lateral Flow Hydrograph를 고려하여 방류계획을 수립한다. EV ROM에서는 댐하류 지역의 첨두홍수량 경감을 위하여 홍수제어지점의 수문곡선 상승부에서 예비방류를, 첨두부에서는 댐에 저류를 하였다가 수문곡선 하강부에 다시 방류를 수행하는 특징이 있다. EV ROM을 강우-유출모형에 결합하여 금강수계 대청댐을 중심으로 3개 홍수사상에 적용해 본 결과, 기존의 Rigid ROM이나 Technical ROM 보다 우수한 것으로 나타났다. 이는 본 연구에서 개발한 EV ROM이 댐 유역뿐만 아니라 댐하류 홍수제어지점의 수문상황을 동시에 고려하여 댐의 방류계열을 결정하기 때문이다. 따라서, 본 연구에서 개발된 EV ROM을 다양한 홍수사상에 적용, 예측강우량의 정확도 개선 및 프로그램의 보완이 이루어진다면, 현재보다 한차원 높아진 저수지운영을 기대 할 수 있을 것이다.

• 산업기술연구
• /
• 제31권A호
• /
• pp.71-78
• /
• 2011

As the need for predicting the flood stage of river from torrential downpouring caused by climate change is increasingly emphasized, the study, centered on the area of Gangwon-do Inje-gun and Jeongseon-gun of local river, is to develop peak water level regression equation by rainfall. Through the correlation between rainfall and peak water level, it is confirmed that rainfall according to duration and peak water level have a high correlation coefficient. Based on this, a relational expression of rainfall and peak water level is verified and then the adequacy of the calculated expression is analyzed and the result shows that a very accurate prediction is not easy to achieve but a rough prediction of the change of water level at each point is possible.

• 한국관개배수논문집
• /
• 제17권2호
• /
• pp.57-70
• /
• 2010

This study was performed to analyze the affect of water supply capacity followed by allocating flood control volume in heightening reservoir, of which Baekgog reservoir was selected as a case study in here. Baekgog reservoir is located in Jincheon county, Chungbuk province, of which full water level will be heightened from EL. 100. 1m to EL. 102.1m, and total storage from 21.75M $m^3$ to 26.67M $m^3$. Flood inflow with 200year frequency was estimated to 997 $m^3$/s in peak flow and 22.54M $m^3$ in total volume. Reservoir flood routing was conducted to determine flood limited water levels, which was determined to have scenarios such as EL 97-98-99m in periods of 6.21.-7.20., 7.21.-8.20., and 8.21.-9.20., respectively, EL 97-97-97m, EL 98-98-98m in present reservoir, and EL 99-100-101m, EL 99-99-99m, and EL 100-100-100m in heightened reservoir. Reservoir inflow was simulated by DAWAST model. Annual paddy irrigation requirement was estimated to 33.19M $m^3$ to 2,975ha. Instream flow was allocated to 0.14mm/d from October to April. Operation rule curve was drawn using inflow, irrigation and instream flow requirements data. In case of withdrawal limit reservoir operation using operation rule curve, reduction rates of annual irrigation supply before and after flood control by reservoir were 2.0~4.3% in present size and 1.5~3.6% in heightened size. Reliability on water supply was decreased from 77.3% to 63.6~68.2% in present size and from 81.6% to 72.7~79.5% in heightened size. And reduction rates of water storage at the end of year before and after flood control by reservoir were 7.3~16.5% in present size and 7.7~16.9% in heightened size. But water supplies were done without any water deficiency through withdrawal limit reservoir operation in spite of low flood regulating water level.

• 한국농공학회논문집
• /
• 제62권1호
• /
• pp.17-27
• /
• 2020

The objective of this study was to assess the flood probability based on temporal distribution of forecasted-rainfall in Cheongmicheon watershed. In this study, 6-hr rainfalls were disaggregated into hourly rainfall using the Multiplicative Random Cascade (MRC) model, which is a stochastic rainfall time disaggregation model and it was repeated 100 times to make 100 rainfalls for each storm event. The watershed runoff was estimated using the Clark unit hydrograph method with disaggregated rainfall and watershed characteristics. Using the peak discharges of the simulated hydrographs, the probability distribution was determined and parameters were estimated. Using the parameters, the probability density function is shown and the flood probability is calculated by comparing with the design flood of Cheongmicheon watershed. The flood probability results differed for various values of rainfall and rainfall duration. In addition, the flood probability calculated in this study was compared with the actual flood damage in Cheongmicheon watershed (R² = 0.7). Further, this study results could be used for flood forecasting.

• 한국수자원학회논문집
• /
• 제39권4호
• /
• pp.347-362
• /
• 2006

본 연구에서는 하천 제방붕괴로 인한 제내지에서의 범람홍수의 전파양상을 효율적으로 계산할 수 있는 2차원 범람홍수모형을 개발하였다. 또한 범람모의를 위한 기본 입력자료 구축을 위해서 레이더 자료와 연계하였으며, 레이더 정량강우-홍수유출-범람해석에 대한 통합시스템을 구축하였다. 개발된 모형의 검증을 위해서 태풍 루사로 인한 감천 유역의 실제 제방붕괴 사례에 대한 적용을 실시하였으며, 범람모의를 위한 기본자료인 강우량을 산정하기 위해서 레이더 자료와 연계하였고, 지상의 강우관측자료와 최적으로 조합하기 위한 cokriging 기법을 적용하였다. 레이더와 연계한 2차원 정량강우량은 유역에서의 홍수량 산정을 위해 이용되었으며, 유역에서의 홍수량은 하도 및 제내지에서의 홍수범람모의를 위해 이용되었다. 모의결과는 실제 홍수흔적과 하천에서의 홍수위 자료 등과 비교하여 잘 일치되고 있음을 확인할 수 있었다.

• Ocean Systems Engineering
• /
• 제9권3호
• /
• pp.287-328
• /
• 2019

Comprehensive understanding of the flood risk assessments via frequency analysis often demands multivariate designs under the different notations of return periods. Flood is a tri-variate random consequence, which often pointing the unreliability of univariate return period and demands for the joint dependency construction by accounting its multiple intercorrelated flood vectors i.e., flood peak, volume & durations. Selecting the most parsimonious probability functions for demonstrating univariate flood marginals distributions is often a mandatory pre-processing desire before the establishment of joint dependency. Especially under copulas methodology, which often allows the practitioner to model univariate marginals separately from their joint constructions. Parametric density approximations often hypothesized that the random samples must follow some specific or predefine probability density functions, which usually defines different estimates especially in the tail of distributions. Concentrations of the upper tail often seem interesting during flood modelling also, no evidence exhibited in favours of any fixed distributions, which often characterized through the trial and error procedure based on goodness-of-fit measures. On another side, model performance evaluations and selections of best-fitted distributions often demand precise investigations via comparing the relative sample reproducing capabilities otherwise, inconsistencies might reveal uncertainty. Also, the strength & weakness of different fitness statistics usually vary and having different extent during demonstrating gaps and dispensary among fitted distributions. In this literature, selections efforts of marginal distributions of flood variables are incorporated by employing an interactive set of parametric functions for event-based (or Block annual maxima) samples over the 50-years continuously-distributed streamflow characteristics for the Kelantan River basin at Gulliemard Bridge, Malaysia. Model fitness criteria are examined based on the degree of agreements between cumulative empirical and theoretical probabilities. Both the analytical as well as graphically visual inspections are undertaken to strengthen much decisive evidence in favour of best-fitted probability density.