• 한국제4기학회지
• /
• 제17권2호
• /
• pp.63-69
• /
• 2003

Three tree-ring monsoon rainfall reconstructions from China and Korea have been used in this paper to investigate the variation of the East Asian summer monsoon over the past 160 years. Statistically, there is no linear correlation on a year-by-year basis between Chinese and Korean monsoon rainfall, but region-wide synchronous variation on decadal-scale was observed. Strong monsoon intervals (more rainfall) were 1860-1890, 1910-1925,1940-1960, and weak monsoon periods (dry or even drought) were 1890-1910, 1925-1940, 1960- present. Reconstructions also display that the East Asian summer monsoon suddenly changed from strong into weak around mid-1920, and the East Asian summer monsoon keeps going weak after 1960.

• 대기
• /
• 제22권1호
• /
• pp.129-135
• /
• 2012

This study restores rainfall measurements taken with the Chugugi (rain gauge) at Wonju, Hamheung, and Haeju from the Deungnok (government records from the Joseon Dynasty). We restored rainfall data corresponding to a total of 9, 13, and 18 years for Wonju, Hamheung, and Haeju, respectively. Based on the restored data, we reconstructed monthly rainfall data. Restoration was most successful for the rainy season months of June, July and August. The restored rainfall data were compared with the summer rainfall data for Seoul as recorded by the Seungjeongwon (Royal Secretariat). In June, the variation in the restored rainfall data was similar to that of the Seungjeongwon data for Seoul. In July and August, however, the variations in the reconstructed data were markedly different from those in the Seoul data (Seungjeongwon). In the case of the worst drought in the summer of 1888, a substantial shortage of rainfall was found in both the Seungjeongwon data for Seoul and the restored data for the three regional locations.

• 한국농림기상학회지
• /
• 제4권3호
• /
• pp.169-174
• /
• 2002

When the long - lasting stationary fronts were pushed northward by the Pacific Highs in late July, mostly clear skies with intermittent showers were a typical weather of August in Korea. However, torrential rains and flash floods are now a seasonal event of August in recent years. Some meteorologists suspect this unusual phenomenon might be connected with the global change and are concerned about the possibility of change in summer climatic pattern in Korea. August of year 2002 must be remembered to be one of the record breaking months with respect to the rainfall events. In this paper, we analyzed the weather and crop data nationwide for August in 2002, and suggest a few countermeasures necessary to overcome the wet and cool summer impacts on agricultural sector.

• 물과 미래
• /
• 제11권2호
• /
• pp.62-69
• /
• 1978

Interstational and interseasonal analyses of the correlation and variability in the seasonal and annual precipitation for 10 basic synoptic stations in South Korea, on the basis of rainfall record of over 40 years, are carried out. It is found that the climatic regions of precipitation could be classified by means of the interstational analysis for the correlations. Corrleation coefficients in interstational relationship of precipitation are lowest in autumn which characterizeds a strong locality while the highest value shows a relatively weak locality in winter. Interseasonal relationship between summer and winter precipitation shows mostly 10 percent significant level with all positive values. The magnitude of the variation coefficients are appeared to be in the order of winter, autumn, spring and summer. It is shown that the highest which is winter ranges between 0.33 0.58, and for the lowest summer, 0.26-0.44, respectively in the areal distribution of the coefficient. The secular changes of the variation coefficient in the recent trend show increases in spring at two station; Seoul and Incheon, in summer at Busan and in autumn at two stations; Busan and Incheon while in winter show devreases at the whole stations. An annual variation seems to show generally a constant trend as whole for all the stations.

• 대기
• /
• 제17권2호
• /
• pp.115-123
• /
• 2007

The present study uses the GOES IR brightness temperature to examine the temporal and spatial variability of cloud activity over the region $25^{\circ}N-45^{\circ}N$, $105^{\circ}E-135^{\circ}E$ and analyzes the coherence of eastern Asian summer season rainfall in Weather Research and Forecast (WRF) model. Time-longitude diagram of the time period from June to July 2005 shows a signal of eastward propagation in the WRF model and convective index derived from GOES IR data. The rain streaks in time-latitude diagram reveal coherence during the experiment period. Diurnal and synoptic scales are evident in the power spectrum of the time series of convective index and WRF rainfall. The diurnal cycle of early morning rainfall in the WRF model agrees with GOES IR data in the Korean Peninsula, but the afternoon convection observed by satellite observation in China is not consistent with the WRF rainfall which is represented at the dawn. Although there are errors in strength and timing of convection, the model predicts a coherent tendency of rainfall occurrence during summer season.

• Current Research on Agriculture and Life Sciences
• /
• 제32권4호
• /
• pp.203-209
• /
• 2014

This study investigated characteristics of rainfall and water quality in Saemangeum area with attention to temporal and spatial distributions. A high variability in rainfall was noted during July and August. The temporal analysis of water quality data indicated that DO and TN as well as BOD, COD and SS were within national standards except for increased concentrations during spring and summer, unlike TP values that indicated poor water quality. Standard deviation showed a high variability in SS among the seasons most especially during summer. The high dispersion indicated variability in the chemical composition of pollutants where the temporal and spatial variations caused by polluting sources and/or seasonal changes were most evident for BOD and COD during winter and spring. The box plots and bar charts showed steadily low concentrations of BOD, COD, TN and TP except within Iksan and notable significant variations in SS concentrations among the monitoring stations. Thus, high pollution levels requiring intervention were identified in Mangyeong river basin with particular concern for areas represented by Iksan station. It was noted that Iksan received a considerable amount of rainfall which meant high runoff which could explain the significant pollution levels revealed in the water quality spatial distribution. Major pollution contributing pollutants within Saemangeum area were identified as SS, BOD, COD and TN. Therefore the present results could be used as a guideline for the temporal and spatial distributions analysis of both rainfall and water quality in Saemangeum watershed.

• 한국지구과학회지
• /
• 제38권1호
• /
• pp.35-48
• /
• 2017

이 연구는 한국-중국 북부 지역($35^{\circ}-40^{\circ}N$, $110^{\circ}-130^{\circ}E$)에서 영역평균 된 여름(6-8월) 강수량의 증가경향이 1990년대 후반에 뚜렷하게 나타났음을 분석하였다. 따라서 한국-중국 북부지역에서 1998년 이후에 여름 강수량이 증가한 원인을 알아보기 위해 1998-2012년 평균과 1981-1997년 평균 사이에 종관환경에 대한 차를 분석하였다. 850 hPa 유선분석에서는 북태평양 지역과 호주 동쪽지역에서 거대한 고기압성 순환 아노말리가 강화되었다. 양반구에서 이러한 순환 아노말리에 의해 적도 중태평양으로부터 열대 서태평양에 편동풍 아노말리(무역풍 아노말리)가 강화되었다. 이는 라니냐 해에 나타나는 순환 패턴의 아노말리였다. 200 hPa 유선에서는 남 북태평양 모두에서 거대한 저기압성 순환 아노말리가 역시 강화되었다. 이러한 두 순환 아노말리에 의해 적도 중태평양 및 서태평양에서는 서풍의 아노말리가 강화되었다. 이는 1990년대 후반 이후 한국-중국 북부 지역에서 여름 강수량의 증가가 라니냐 패턴과 연관되었으며, 이 결과는 결국 워커 순환의 강화로 이어졌다. 또한 최근 동아시아 지역에서는 적도 서태평양과 동아시아 중위도 지역에서 상승한 기류가 아열대 서태평양지역에서 하강하는 지역 해들리 순환이 강화되었다.

• 상하수도학회지
• /
• 제32권2호
• /
• pp.169-181
• /
• 2018

For performance analysis of flood prevention projects, this study performed simulation (SWMM) for the five sites where the projects have been completed. The models were constructed using watershed and sewer information of the project sites and were verified using flood records in the past to improve accuracy. In this simulation, the design rainfall data (probability 30~50 years) and the rainfall data in the summer of 2017 were applied. When the design rainfall data was applied to the models, simulation results presented that all the sites were flooded before the projects, but after the projects all the sites were not flooded due to improve discharge capacity. And when the rainfall data in the summer of 2017 was applied to the models, simulation results presented that all the sites were flooded before the projects, but after the projects any sites did not occur flooding in this summer. So if the projects had not been completed, all the sites might be flooded in the summer of 2017. These effects were analyzed as the improvement of discharge capacity due to rehabilitation of sewer, construction of underground tunnel and pumping station, etc. As the results, ratio of sewer that water depth exceed diameter reduced from 52.3~75.8% to 17.1~39.8%.

• 지질공학
• /
• 제31권4호
• /
• pp.631-646
• /
• 2021

본 연구에서는 2011년부터 2020년까지의 연구지역에서 발생한 산사태와 강우 요인들을 통해 강우 지속성과 산사태 발생 빈도의 연관성을 분석하였다. 연구지역은 강원도, 경기도, 경상남도, 경상북도, 전라남도, 전라북도, 충청남도의 총 7개 지역이며 분석에 활용한 강우 요인은 6월, 7월, 8월의 월 강우량과 여름기간(6~8월) 강우량, 장마기간 강우량, 여름기간 강수일수, 장마기간 강수일수이다. 연구지역별로 산사태 발생이 많았던 해의 강우 요인을 비교·분석하여 강우 지속성이 산사태 발생에 미치는 영향을 파악하였다. 연구결과 강우량뿐만 아니라 장마기간 강수일수도 산사태 발생에 영향을 미치는 것으로 확인되었으며, 2020년의 산사태 발생 급증은 2020년의 장마기간 강수일수가 많은 것에서 기인한 것으로 추정되었다. 이러한 결과는 추후 강우 지속성의 영향을 고려한 산사태 경보 기준의 기초 자료로 활용될 수 있을 것으로 기대된다.

• Animal cells and systems
• /
• 제16권3호
• /
• pp.260-267
• /
• 2012

Calling behavior is often used to infer breeding patterns in anurans. We studied the seasonal and diel calling activities of anuran species in a wetland in central Korea to determine the calling season and to evaluate the effects of abiotic factors on male calling. Acoustic monitoring was used in which frog calls were recorded for a full day, once a week, throughout an entire year. Using acoustic monitoring, we identified three frog species in the study site. Males of Rana dybowskii called in late winter and early spring; we thus classified this species as a winter/spring caller. The results of binary logistic regression showed that temperature, relative humidity, and 1-day lag rainfall were significant factors for male calling in R. dybowskii. Temperature and relative humidity were important factors for the calling activity of R. nigromaculata, whereas 24-h rainfall and 1-day lag rainfall were not significant. Thus, we determined R. nigromaculata to be a summer caller independent of weather. In Hyla japonica, relative humidity, 24-h rainfall, and 1- day lag rainfall were significant for male calling, suggesting that this species is a summer caller dependent on local rain.