• 대한토목학회논문집
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• 제30권6B호
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• pp.579-587
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• 2010

기상청에서 제공하는 강우수치예보정보를 활용하여 10일이내의 중기유량예측을 수행하였다. 기상청의 원시예보자료로는 2일예보를 위한 RDAPS와 10일예측을 위한 GDAPS예측자료를 활용하였다. 수치예보의 정확도를 제고하기 위하여 강우상세 정보를 생산할 수 있는 강수진단모형(QPM)과 QPM모의결과에 내재된 계통적 편이를 제거하기 위하여 분위사상과정 (Quantile Mapping)을 적용하였다. QPM모의결과를 유출모형의 입력정보로 활용하기 위하여 일관적인 체계를 갖춘 유역강수 정보로 변환하여, 장기연속유출모형인 SSARR모형을 이용하여 금강유역내 주요지점에서의 유량예측을 수행하여 유량예측에 대한 검증을 수행하였다. 2006년 1월 1일부터 6월 20일까지 강수예측을 수행한 결과 2일예측인 RQPM의 경우 기간 총강수량을 기준으로 실적강우대비 89.7%의 강수모의값을 보임으로서 양호한 예측성능을 확인할 수 있었다. 유량예측모의에 있어서는 2일예측의 경우 일부 강우사상에서 예측누락과 예측오류가 발생하였지만 전반적으로 유량예측이 양호한 수준이었다. 다만, 하류지점의 경우 조절유량에 의한 유출모형보정의 어려움과 수위-유량관계곡선의 신뢰도저하등의 이유로 예측성능이 떨어지는 경우도 있었다. GQPM에 대한 10일강우예측은 첨두강수와 강수총량에 있어서 다소 과소한 모의값을 보이고 있으며, 강수보정효과도 RDAPS에 비하여 저조한 수준이었다. 이 부분은 강수예측의 사후보정으로는 한계가 있는 것으로 보여지며 원시예측모형의 안정화를 통하여 개선할 수 있는 부분으로 판단된다.

• 환경영향평가
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• 제22권1호
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• pp.39-50
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• 2013

Occurrence of landslides has been increasing due to extreme weather events(e.g. heavy rainfall, torrential rains) by climate change. Pyeongchang, Korea had seriously been damaged by landslides caused by a typhoon, Ewiniar in 2006. Moreover, the frequency and intensity of landslides are increasing in summer due to torrential rain. Therefore, risk assessment and adaptation measure is urgently needed to build resilience. To support landslide adaptation measures, this study predicted landslides occurrence using MaxEnt model and suggested susceptibility map of landslides. Precipitation data of RCP 8.5 Climate change scenarios were used to analyze an impact of increase in rainfall in the future. In 2050 and 2090, the probability of landslides occurrence was predicted to increase. These were due to an increase in heavy rainfall and cumulative rainfall. As a result of analysis, factors that has major impact on landslide appeared to be climate factors, prediction accuracy of the model was very high(92%). In the future Pyeongchang will have serious rainfall compare to 2006 and more intense landslides area expected to increase. This study will help to establish adaptation measure against landslides due to heavy rainfall.

• 대기
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• 제26권1호
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• pp.97-109
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• 2016

Heavy rainfall (over $80mm\;hr^{-1}$) system associated with unstable atmospheric conditions occurred over the Seoul metropolitan area on 27 July 2011. To investigate the heavy rainfall system, we used three-dimensional data from Korea Local Analysis and Prediction System (KLAPS) reanalysis data and analysed the structure of the precipitation system, kinematic characteristics, thermodynamic properties, and Meteorological condition. The existence of Upper-Level Jet (ULJ) and Low-Level Jet (LLJ) are accelerated the heavy rainfall. Convective cloud developed when a strong southwesterly LLJ and strong moisture convergence occurring around the time of the heavy rainfall is consistent with the results of previous studies on such continuous production. Environmental conditions included high equivalent potential temperature of over 355 K at low levels, and low equivalent potential temperature of under 330 K at middle levels, causing vertical instability. The tip of the band shaped precipitation system was made up of line-shaped convective systems (LSCSs) that caused flooding and landslides, and the LSCSs were continuously enhanced by merging between new cells and the pre-existing cell. Difference of wind direction between low and middle levels has also been considered an important factor favouring the occurrence of precipitation systems similar to LSCSs. Development of LSCs from the wind direction difference at heights of the severe precipitation occurrence area was also identified. This study can contribute to the identification of production and development mechanisms of heavy rainfall and can be used in applied research for prediction of severe weather.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.1142-1146
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• 2009

A rainfall simulation and forecasting technique that can generate daily rainfall sequences conditional on multi-model ensemble GCMs is developed and applied to data in Korea for the major rainy season. The GCM forecasts are provided by APEC climate center. A Weather State Based Downscaling Model (WSDM) is used to map teleconnections from ocean-atmosphere data or key state variables from numerical integrations of Ocean-Atmosphere General Circulation Models to simulate daily sequences at multiple rain gauges. The method presented is general and is applied to the wet season which is JJA(June-July-August) data in Korea. The sequences of weather states identified by the EM algorithm are shown to correspond to dominant synoptic-scale features of rainfall generating mechanisms. Application of the methodology to seasonal rainfall forecasts using empirical teleconnections and GCM derived climate forecast are discussed.

• Environmental Engineering Research
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• 제22권2호
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• pp.162-168
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• 2017

Rainfall is one of the most important phenomena of the natural system. In Bangladesh, agriculture largely depends on the intensity and variability of rainfall. Therefore, an early indication of possible rainfall can help to solve several problems related to agriculture, climate change and natural hazards like flood and drought. Rainfall forecasting could play a significant role in the planning and management of water resource systems also. In this study, univariate Seasonal Autoregressive Integrated Moving Average (SARIMA) model was used to forecast monthly rainfall for twelve months lead-time for thirty rainfall stations of Bangladesh. The best SARIMA model was chosen based on the RMSE and normalized BIC criteria. A validation check for each station was performed on residual series. Residuals were found white noise at almost all stations. Besides, lack of fit test and normalized BIC confirms all the models were fitted satisfactorily. The predicted results from the selected models were compared with the observed data to determine prediction precision. We found that selected models predicted monthly rainfall with a reasonable accuracy. Therefore, year-long rainfall can be forecasted using these models.

• Korean Journal of Hydrosciences
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• 제3권
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• pp.97-104
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• 1992

To design the minor structures in the small watersheds, it is required to calculate the peak discharge. For these calculations the simple peak flow prediction equations, the unit hydrograph method. the syntheic unit hydrograph methods or the runoff simulation models are adopted. To use these methods it is generally requried to know the amount and the distributions of the design rainfall; which are the uniform distribution, the trangular distribution, the trapezoidal distribution, or the Huff type distribution. In this study, the peak discharges are calculated by the different rainfall distributions and the results are compared.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.224-224
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• 2015

The East Asia monsoon is one of the most complex atmospheric phenomena caused by Land-Sea thermal contrast. It plays essential role in fulfilling the water needs of the region but also poses stern consequences in terms of flooding and droughts. This study analyzed the influence of Global Sea Surface Temperature Anomalies (SSTA) on occurrence of droughts in the East Asia monsoon region ($20^{\circ}N-50^{\circ}N$, $103^{\circ}E-149^{\circ}E$). Standardized Precipitation Index (SPI) was employed to characterize the droughts over the region using 30-year (1978-2007) gridded rainfall dataset at $0.5^{\circ}$ grid resolution. Due to high variability in intensity and spatial extent of monsoon rainfall the East Asia monsoon region was divided into the homogeneous rainfall zones using cluster analysis method. Seven zones were delineated that showed unique rainfall regimes over the region. The influence of SSTA was assessed by using lagged-correlation between global gridded SSTA ($0.2^{\circ}$ grid resolution) and SPI of each zone. Sea regions with potential influence on droughts in different zones were identified based on significant positive and negative correlation between SSTA and SPI with a lag period of 3-month. The results showed that SSTA have the potential to be used as predictor variables for prediction of droughts with a reasonable lead time. The findings of this study will assist to improve the drought prediction over the region.

• 한국전자파학회논문지
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• 제11권5호
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• pp.813-821
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• 2000

위성통신 경로의 강우감쇠량을 예측하기 위하여 국제적으로 여러 가지 예측모델들이 개발 운용되고 있다. 이러한 예측 모델들은 대부분 미국과 유럽을 비롯한 위성 선진국에서 개발한 것으로 국내의 강우환경을 고려하여 개발된 모델은 없는 실정이다. 본 논문에서는 한국전자통신연구원에서 측정한 강우환경 및 강우감쇠 데이터를 이용하여, 국내 위성통신망에서 고려할 수 있는 강우감쇠량 예측 방법에 대해 기술하였다. 특히, 기존 예측 모델들이 적용한 강우경로의 수평적 변화를 고려한 유효경로 길이 예측 기법에서 탈피하여, 위성통신망에서 필연적으로 고려하여야 할 강우경로의 수직적 변화까지도 고려한 유효경로 예측기법을 유도하고 이를 제안하였다. 본 논문에서 제안한 예측 기법은 국내 강우환경에 적합한 예측 기법으로써, 향후 설계 및 운용될 10GHz 이상의 국내 위성 및 무선통신시스템에 매우 효율적으로 활용할 수 있을 것이다. ^u The engineering of satellite communication systems at frequencies above 10GHz requires a method for estimating rain-caused outage probabilities on the earth-satellite path. A procedure for predicting a rain attenuation distribution from a point rainfall rate distribution is, therefore, needed. In order to predict rain attenuation on the satellite link, several prediction models such as ITU-R, Global, SAM, DAH model, have been developed and used at a particular propagation condition, they may not be appropriate to a propagation condition in Korean territory. In this paper, a new rain attenuation prediction method appropriate to a propagation condition in Korea is introduced. Based on the results from ETRI measurements, a new method has been derived for an empirical approach with an identification on the horizontal correction factor as in current ITU-R method, and the vertical correction factor has been suggested with decreasing power law as a function of rainfall rate. This proposed model uses the entire rainfall rate distribution as input to the model, while the ITU-R and DAH model approaches only use a single 0.01% annual rainfall rate and assume that the attenuation at other probability levels can be determined from that single point distribution. This new model was compared with several world-wide prediction models. Based on the analysis, we can easilty know the importance of the model choice to predict rain attenuation for a particular location in the radio communication system design.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.448-451
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• 2005

This paper presents the methodology to analyze flow duration characteristics and performance prediction for small hydro power(SHP) plants and its application. The flow duration curvecan be decided by using monthly rainfall data at the most of the SHP sites with no useful hydrological data. It was proved that the monthly rainfall data can be characterized by using the cumulative density function of Weibull distribution and Thiessen method were adopted to decide flow duration curve at SHP plants. And, the performance prediction has been studied and development. One SHP plant was selected and performance characteristics was analyzed by using the developed technique. Primary design specfications such as design flowrate, plant capacity, operational rate and annual electricity production for the SHP plant were estimated. It was found that the methodology developed in this study can be a useful tool to predict the performance of SHP plants and candidate sites in Korea.

• 대한토목학회논문집
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• 제2권3호
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• pp.43-56
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• 1982

상태공간(狀態空間) 개념(槪念)에 기초(基礎)를 두어 시스템의 동적(動的) 거동(擧動)을 나타낸 Kalman filter와 자기공진(自己共振) 예측자(豫測子)의 순환(循還) 알고리즘에 의한 예측방법(豫測方法)을 연구(硏究)하여 하천유출(河川流出) 예측(豫測)에의 적용성(適用性)을 검토(檢討)하고 그 결과(結果)를 제시하였다. 강우(降雨)-유출과정(流出過程)의 동적(動的) 거동(擧動)을 자색(白色) Gaussian 잡음(雜音)이 있는 선형(線型), 이산형(離散型)시스템으로 보아서 낮은 차수(次數)의 ARMA 과정(過程)으로 나타내었으며 예측모형(豫測模型)의 상태(狀態)벡터를 random walk로 나타내었다. 예측오차(豫測誤差)에 대한 통계적(統計的)인 분석(分析)으로 모형구조(模型構造)를 결정하였으며 적용(適用)된 예측(豫測)알고리즘의 검정(檢正)을 위하여 시우량(時雨量)과 시유량(時流量)의 과거(過去) 기록치(記錄値)를 사용하였다. 예측결과(豫測結果)를 분석(分析)하나 Kalman filter에 의한 알고리즘이 자기공진(自己共振) 예측자(豫測子)보다 우수하다는 것을 알 수 있었다.