• 한국농공학회논문집
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• 제53권3호
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• pp.1-11
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• 2011

The temporal variability of spring (March, April, May) monthly precipitation, precipitation effectiveness, monthly maximum precipitation, monthly precipitation of different durations, and the precipitation days over several threshold (i.e. 0, 10, 20, 30, 40, and 50 mm/day) of 59 weather stations between 1973 and 2009 were analyzed. Also to analyze the regional characteristics of temporal variability, 59 weather stations were classified by elevations, latitudes, longitudes, river basins, inland or shore (east sea, south sea, west sea) area and the level of urbanization. Results demonstrated that trends of variables increase in April and decrease in May except precipitation day. Overall trend of precipitation amount and precipitation effectiveness is same but precipitation effectiveness of several sites decrease despite the trend of precipitation amount increases which may be caused by the air temperature increase. Therefore more effective water supply strategy is essential for Spring season. Regional characteristics of Spring precipitation variability can be summarized that increase trend during May become stronger with the increase of latitude and elevation which is similar to that of Summer season. The temporal variability of variables showed different behaviors according to river basins, inland or shore (east sea, south sea, west sea) area and the level of urbanization.

• 한국환경과학회지
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• 제2권3호
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• pp.179-191
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• 1993

This paper aims to know the characteristics of occurrence of the anomaly level and variability of the monthly precipitation in Kyeongnam, Korea. For this study, it was investigated 주e distribution of the annual and cont비y mean precipitation, the precipitation variability and its annual change, and the characteristics of occurrence of the anomaly level in Kyeongnam area the results were summarized as follows : 1) she mean of annual total precipitation averaged over Kyeongnam area is 1433.3mm. I'he spatial distribution of the annual total precipitation shows that in Kyeongnam area, the high rainfall area locates in the southwest area and south coast and the low rainfall area in an inland area. 2) Monthly mean precipitation in llyeongnam area was the highest in July(266.4mm) 각lowed by August(238.0mm), June(210.2mm) in descending order. In summer season, rainfall was concentrated and accounted for 49.9 percent of the annual total precipitation. Because convergence of the warm and humid southwest current which was influenced by Changma and typhoon took place well in this area. 3) The patterns of annual change of precipitaion variability can be divided into two types; One is a coast type and the other an inland type. The variability of precipitation generally appears low in spring and summer season and high in autumn and winter season. This is in accord with the large and small of precipitation. 4) The high frequency of anomaly level was N( Normal)-level and the next was LN( Low Informal) -level and 25(Extremely Subnormal)-level was not appeared in all stations. The occurrence frequency of N level was high in high rainfall area and distinguish성 in spring and summer season but the low rainfall area was not. hey Words : anomaly level, variability, precipitation, coast type, inland type.

• 한국지구과학회지
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• 제24권1호
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• pp.22-29
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• 2003

Temporal and spatial variability of precipitation (P), evaporation (E), and moisture balance (P-E; precipitation minus evaporation) has been investigated over the tropical ocean during the period from January 1998 to July 2001. Our data were analyzed by the EOF method using the satellite P and E observations made by the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and the Special Sensor Microwave/Imager (SSM/I). This analysis has been performed for two three-year periods as follow; The first period which includes the El Ni${\tilde{n}}$o in early 1998 ranges from January 1998 to December 2000, and the second period which includes the La Ni${\tilde{n}}$o events in the early 1999 and 2000 (without El Ni${\tilde{n}}$o) ranges from August 1998 to July 2001. The areas of maxima and high variability in the precipitation and in the P-E were displaced from the tropical western Pacific and the ITCZ during the La Ni${\tilde{n}}$o to the tropical middle Pacific during the El Ni${\tilde{n}}$o, consistent with those in previous P studies. Their variations near the Korean Peninsula seem to exhibit a weakly positive correlation with that in the tropical Pacific during the El Ni${\tilde{n}}$o. The evaporation, out of phase with the precipitation, was reduced in the tropical western Pacific due to humid condition in boreal summer, but intensified in the Kuroshio and Gulf currents due to windy condition in winter. The P-E variability was determined mainly by the precipitation of which the variability was more localized but higher by 2-3 times than that of evaporation. Except for the ITCZ (0-10$^{\circ}$N), evaporation was found to dominate precipitation by ${\sim}$2 mm/day over the tropical Pacific. Annual and seasonal variations of P, E, and P-E were discussed.

• 한국농공학회논문집
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• 제64권6호
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• pp.101-112
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• 2022

Extreme precipitation events have recently become a leading cause of disasters. Thus, investigating the variability and trends of extreme precipitation is crucial to mitigate the increasing impact of such events. Spatial distribution and temporal trends in annual precipitation and four extreme precipitation indices of duration (CWD), frequency (R10 mm), intensity (Rx1day), and percentile-based threshold (R95pTOT) were analyzed using the daily precipitation data of 10 observation stations in Chungcheong province during 1974-2020. The precipitation at all observation stations, except the Boryeong station, showed nonsignificant increasing trends at 95% confidence level (CL) and increasing magnitudes from the west to east regions. The high variability in mean annual precipitation was more pronounced around the northeast and northwest regions. Similarly, there were moderate to high patterns in extreme precipitation indices around the northeast region. However, the precipitation indices of duration and frequency consistently increased from the west to east regions, while those of intensity and percentile-based threshold increased from the south to east regions. Nonsignificant increasing trends dominated in CWD, R10 mm, and Rx1day at all stations, except for R10 mm at Boeun station and Rx1day at Cheongju and Jecheon stations, which showed a significantly increasing trend. The spatial distribution of trend magnitude shows that R10 mm increased from the west to east regions. Furthermore, variations in precipitation were very strongly correlated (99% CL) with R10 mm, Rx1day, and R95pTOT at all stations, except with wR10 mm at Cheongju station, which was strongly correlated with a 95% CL.

• 대기
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• 제22권4호
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• pp.449-454
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• 2012

This study presents the long-term variability of spring precipitation over the Korean peninsula. It is found that the significant interdecadal change in the spring precipitation has occurred around year 1991. Over the Korean peninsula the precipitation for the post-1991 period increased by about 30 mm per year in CMAP and station-measured data compared to the precipitation prior to year 1991. Due to an increased baroclinicity during the later period, the low-level negative pressure anomaly has developed with its center over northern Japan. Korea is situated at the western end of the negative pressure anomaly, receiving moisture from westerly winds and producing more precipitation. Also, we estimate the change in the near future (years 2020~2040) spring precipitation using six best performing Coupled Model Intercomparison Project 3 (CMIP3) models. These best model ensemble mean shows that spring precipitation is anticipated to increase by about 4% due to the strengthened westerlies accompanied by the northwestern enhancement of the North Pacific subtropical high.

• Spatial Information Research
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• 제15권3호
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• pp.267-278
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• 2007

국제사회는 기후변화에 따른 이상 현상의 징후가 발생함에 따라 이의 영향 예측을 위해 많은 모델들을 개발 및 적용하고 있다. 현재 우리나라에서도 여러 분야의 기후 영향모델 활용이 증가하면서 모델의 입력자료 중 특히 기후자료의 구축 방법 및 한반도 기후의 특성 파악에 대한 연구가 절실히 요구되고 있다. 본 연구에서는 보간을 위하여 공간통계학방법 중 IDSW(Inverse Distance Squared Weighting:거리자승역산가중)를 적용하였다. 이 방법은 미관측지점의 값을 추정하기 위하여 주변 관측지점들을 고려하며, 그 영향은 거리에 반비례함을 반영한다. 여기서 주변 관측지점 선정시 반경 100km내의 가장 인접한 순으로 최대 3개의 관측지점을 선택하게 제약을 두었다. 그 결과 한국의 기온과 강수량 모두 과거 30년 동안에 연평균 약 $0.4^{\circ}C$, 412mm 증가하는 것으로 나타났다. 또한 미래에도 2007년에 비해 2100년의 기온이 $3.96^{\circ}C$, 강수량이 319mm 증가하는 것으로 나타났다. 기후변이성의 특성은 과거 30년 동안 기온의 경우 강원도 일부지역이 높게 나타났으며 강수량의 경우 남부지역이 높게 나타났다. 변화 경향은 기온의 경우 강원도 지역이 변이성이 증가하는 경향을 보였으며, 강수량의 경우 남동부부지역이 변이성이 증가하는 경향을 보였다. 미래 30년간의 변이성 분석결과 기온은 중서부 지역에서, 강수량은 동부지역에서 높은 것으로 나타났고, 변화경향은 기온의 경우 남서부로 갈수록 변이의 정도가 증가되는 경향을 보였으며, 강수량의 경우 중서부와 남부 일부가 변이가 증가되는 경향을 보였다.

• 한국농공학회논문집
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• 제63권6호
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• pp.49-60
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• 2021

BCSA (Bias-Correction and Stochastic Analog) is a statistical downscaling technique designed to effectively correct the systematic errors of GCM (General Circulation Model) output and reproduce basic statistics and spatial variability of the observed precipitation filed. In this study, the applicability of BCSA was evaluated using the ASOS observation data over South Korea, which belongs to the monsoon climatic zone with large spatial variability of rainfall and different rainfall characteristics. The results presented the reproducibility of temporal and spatial variability of daily precipitation in various manners. As a result of comparing the spatial correlation with the observation data, it was found that the reproducibility of various climate indices including the average spatial correlation (variability) of rainfall events in South Korea was superior to the raw GCM output. In addition, the needs of future related studies to improve BCSA, such as supplementing algorithms to reduce calculation time, enhancing reproducibility of temporal rainfall patterns, and evaluating applicability to other meteorological factors, were pointed out. The results of this study can be used as the logical background for applying BCSA for reproducing spatial details of the rainfall characteristic over the Korean Peninsula.

• 한국수자원학회논문집
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• 제44권8호
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• pp.683-694
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• 2011

기후변화에 따른 지역적 영향인 기온 상승과 강수량 변화로 인한 수자원 변화 특성을 파악하기 위하여 기상청(KMA)으로부터 전국 59개 관측지점에 대해서 1973년부터 2009년까지 강수량 및 기온자료를 이용하여 산정한 강수효율자료와 국가수자원관리종합시스템(WAMIS)으로부터 1966년부터 2007년까지 PRMS 모의 유출량 자료를 수집, 분석하였다. 분석결과, 전반적으로 강수효율의 거동은 강수량의 변화 특성을 따르나 지역적으로 강수량이 증가함에도 불구하고 기온 상승에 따라 강수효율이 감소하는 거동을 보였으며, 이는 유출량의 변화 특성과 유사하였다. 또한 유출량의 평균대비 변화율은 강수량 변화보다 상당히 크게 나타나, 기후변화의 영향에 민감한 것으로 나타났다. 강수량이 증가하는 5월~9월을 제외한 전체 기간에 대하여 강수효율은 강수량보다 더 유의한 감소 경향을 나타내고 있어 해당기간의 가용 수자원량이 줄어들 것으로 판단되며, 이러한 특성은 봄, 가을 및 겨울철 수자원 관리에 반영되어야 할 것이다.

• 대한토목학회논문집
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• 제31권2B호
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• pp.129-146
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• 2011

본 연구에서는 지역특성에 따른 우리나라의 여름철(6월-8월) 극한강수의 정량적 변화와 호우빈도의 변화특성을 파악하기 위하여 1973년부터 2009년까지 전국 59개 기상관측소 자료를 이용하여 지속시간별 강수량의 월별 최고치와 한계치(threshold)를 초과한 강수일수를 대상으로 Mann-Kendall 검정을 수행하였다. 또한 기상관측소의 지역적 특성에 따른 변화를 분석하기 위하여 고도, 위도, 경도, 유역, 내륙 및 해안, 도시화 정도 등에 따라 분류하여 분석을 수행하였다. 분석결과, 지역특성에 따른 여름철 극한강수의 변화특성은 연강수량의 공간분포와 같이 지형의 영향을 많이 받는 것으로 나타났다. 여름철 강수일수는 연강수일수의 감소추세와는 반대로 증가하는 것으로 나타나 여름철 강수집중현상이 심화되고 있는 것으로 나타났다. 해안지역보다는 내륙지역이, 도시화 지역일수록 강수량의 증가와 강수일수의 증가현상이 뚜렷하게 나타났으며, 유역별로는 한강 유역이 강수의 양과 빈도의 증가가 더욱 뚜렷한 것으로 나타났다.

• 대기
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• 제20권2호
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• pp.111-130
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• 2010

An uncertainty assessment for precipitation datasets simulated by Atmosphere-Ocean Coupled General Circulation Model (AOGCM) is conducted to provide reliable climate scenario over East Asia. Most of results overestimate precipitation compared to the observational data (wet bias) in spring-fall-winter, while they underestimate precipitation (dry bias) in summer in East Asia. Higher spatial resolution model shows better performances in simulation of precipitation. To assess the uncertainty of spatiotemporal precipitation in East Asia, the cyclostationary empirical orthogonal function (CSEOF) analysis is applied. An annual cycle of precipitation obtained from the CSEOF analysis accounts for the biggest variability in its total variability. A comparison between annual cycles of observed and modeled precipitation anomalies shows distinct differences: 1) positive precipitation anomalies of the multi-model ensemble (MME) for 20 models (thereafter MME20) in summer locate toward the north compared to the observational data so that it cannot explain summer monsoon rainfalls across Korea and Japan. 2) The onset of summer monsoon in MME20 in Korean peninsula starts earlier than observed one. These differences show the uncertainty of modeled precipitation. Also the comparison provides the criteria of annual cycle and correlation between modeled and observational data which helps to select best models and generate a new MME, which is better than the MME20. The spatiotemporal deviation of precipitation is significantly associated with lower-level circulations. In particular, lower-level moisture transports from the warm pool of the western Pacific and corresponding moisture convergence significantly are strongly associated with summer rainfalls. These lower-level circulations physically consistent with precipitation give insight into description of the reason in the monsoon of East Asia why behaviors of individually modeled precipitation differ from that of observation.