• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.14 no.5
• /
• pp.69-79
• /
• 2011

This study assessed the subsurface runoff and peak flow reduction in rain gardens. The results showed that the highest water retention was found in rain garden mesocosms in which Rhododendron lateritium and Zoysia japonica were planted, followed by mesocosms in which either R. lateritium or Z. japonica was planted, and the lowest water retention rate was found in non-vegetated control treatment mesocosms(${\alpha}$ < 0.05). Although higher rainfall intensity caused a decrease of peak flow reduction in both vegetated and non-vegetated treatments, peak flow reduction was the greatest in mesocosms with mixed plants. A rain garden can be an effective tool for environment-friendly stormwater management and improving ecological functions in urban areas. Depending on the purpose such as delaying runoff or increasing infiltration, various plant types should be considered for rain garden designing.

• Journal of Korea Multimedia Society
• /
• v.18 no.7
• /
• pp.793-805
• /
• 2015

Nowadays the amount of data obtained from advanced weather radars is growing to provide higher spatio-temporal resolution. Accordingly radar data compression is important to use limited network bandwidth and storage effectively. In this paper, we proposed a hierarchical compression method for weather radar data having high spatio-temporal resolution. The method is applied to radar reflectivity and evaluated in aspects of accuracy of quantitative rainfall intensity. The technique provides three compression levels from only 1 compressed stream for three radar user groups-signal processor, quality controller, weather analyst. Experimental results show that the method has maximum 13% and minimum 33% of compression rates, and outperforms 25% higher than general compression technique such as gzip.

• Journal of Satellite, Information and Communications
• /
• v.3 no.2
• /
• pp.7-12
• /
• 2008

The study discussed the link analysis for the Ka band satellite broadcasting service in Korea with respect to the transmission schemes based on the DVB-S2 standard. To analyze the effect of the rain fading to the link budget, we estimated the rain attenuation from the measured rainfall intensity in Korea. We analyzed the link budget for the Ka band transponders of Koreasat-3, and DirecTV BSS-99W, and showed the possible link availability with the DVB-S2 transmission schemes for each transponder. Based on the link analysis of the available satellites with the Ka band transponders, we suggested the required EIRP for the satellite which will be employed for the Ka band satellite broadcasting service in Korea.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 1999.10c
• /
• pp.695-700
• /
• 1999

Stream and groundwater qualities of two rural watershes in the upper North Han river basin were monitored for 14months. Six to eight stream sampling sites and two to there groundwater monitoring wells were chosen and water samples were regularyl collected and analyzed with respect to total nitrogen(T-N), total phosphorus(T-P) and total suspended solids(TSS). Monitoring data were graphically analyzed with respect to time.Rainfall amout and intensity seemed to have an impact on stream T-N and T-P concentration changes. TSS concentrations were generally lower than the first class stream water quality standared, Both stream and groundwater qualities near livesstock feetlot areas were degraded indicating the feedlots have an impact on water quality.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2004.05b
• /
• pp.328-332
• /
• 2004

본 연구에서는 자연하천유역에 적합한 저류상수 산정공식을 개발하기 위하여 섬진강 유역에 대한 유역특성인자 및 강우특성인자를 분석하고, 이의 단계별 회귀분석으로부터 유역면적, 하도연장, 하도경사의 유역특성인자뿐만 아니라 강우특성인자인 유효강우강도를 설명변수로 갖는 저류상수 산정공식을 개발하였다. 그리고 개발된 공식의 적용성을 검토하고자 Clark의 단위도 모형에 기존의 경험공식 및 본 인구에서 개발된 공식을 이용하여 섬진강 유역의 실제 호우사상에 대한 유출수문곡선을 분석하여 관측수문곡선과 비교 검토한 겉과, 본 연구에서 개발된 공식에 의한 유출수문곡선이 관측치에 가장 적합하였다. 또한, 남한강의 지류인 섬강 유역에 대한 빈도별 설계강우량을 적용하여 저류상수 및 설계홍수량을 산정하고 기존에 분석된 저류상수 및 홍수량과 비교 검토한 결과 빈도별 유효강우강도의 변화를 고려한 저류상수의 적용 가능성 및 그 타당성을 확인할 수 있었다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2004.05b
• /
• pp.195-199
• /
• 2004

수공구조물의 설계시 확률강우강도와 홍수유출량의 정확한 산정은 경제성 및 안전성과 관련되어 필수인 과정이다. 현재 확률강우강도의 산정은 한국건설기술연구원에서 제시한 확률강우량도를 사용하고 있으나, 설계자의 주관에 따른 오차 발생의 소지가 있고 수치모의시 수작업에 따른 불리함과 지속기간에 따른 강우강도의 일관성 결여 등 공학적으로 불리하다. 본고에서는 시간적(재현기간별) 공간적으로 형식의 통일과 표준화를 기하고 공학적 사용의 편리를 위하여 단순한 형태의 일반형 확률강우강도식을 개발하여 암거설계의 편리를 도모다. 또한 기존 암거설계법을 재검토하여 미흡한 부분을 보완하였다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2010.05a
• /
• pp.1951-1955
• /
• 2010

우량관측용으로 사용되고 있는 강우량계는 전도형, 저수형, 로드셀형, 중량식 등이 있으며 이 중 측정과 신호의 처리가 간편한 전도형 우량계가 널리 사용되고 있다. 우량관측은 목적에 따라 기상청은 0.5 mm 급 전도형 우량계를 주로 사용하고 있으며, 국토해양부에서는 1 mm 급 전도형 우량계를 주로 사용하고 있다. 본 연구에서는 강우량 증가 및 강우강도에 따른 0.5 mm 및 1 mm 급 전도형 우량계의 측정값을 분석하여 실제값과 얼마의 오차를 보이는지 그 특성을 비교 분석하였다. 이 실험은 수문조사기기 검정대행기관인 유량조사사업단에서 우량계 검정에 사용하고 있는 강우량 검정용 기준기를 이용하여 10~20 mm 강우량 및 20~100 mm/h의 강우강도 변화에 따라 0.5 mm 및 1 mm 급 전도형 우량계의 측정값을 비교하여 각 우량계에 대한 특성을 분석하였다. 본 연구는 향후 실제 강우에 대한 같은 특성 분석 연구를 통해 이 결과를 확인 및 보완하는 연구를 진행할 예정이다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2017.05a
• /
• pp.436-436
• /
• 2017

IDF(intensity-duration-frequency) 곡선은 재현기간을 고려하여 수공구조물 설계에 필요한 설계강우량을 산정하는데 사용되고 있다. 국내의 경우 IDF 곡선은 지점빈도해석으로부터 지속기간별로 산정되고 있으며 지속기간별 분포형 선택과 같은 많은 가정으로 인해 불확실성을 내포하고 있다. 본 연구에서는 이러한 극한 강우량의 스케일 특성을 통해 서로 다른 기간에 걸쳐 통계적으로 접근하고자 하였다. 이를 위해 지속기간 24시간의 강우자료로부터 연최대강우량을 추출하여 스케일 특성을 통해 지속기간 24시간 이하 또는 이상의 스케일링(scaling) IDF 곡선을 유도하였다. 본 연구를 위해 k-means 방법으로부터 지역을 구분하여 지역빈도해석을 실시하였고, 기상청 산하의 강우 지점을 미계측 지점으로 가정한 후 하향스케일링(down-scaling)과 상향스케일링(up-scaling)을 적용한 후 지속기간 24시간 이외의 확률강우량을 추정하였으며, 빈도해석 결과와의 비교를 통해 스케일링 IDF 곡선의 적용성을 판단하였다.

• Journal of the Korean earth science society
• /
• v.27 no.2
• /
• pp.149-158
• /
• 2006

This study analyzes the seasonality precipitation using precipitation data from 1973 to 2001 over South Korea. The Seasonality Index and Annual variation of the Seasonality Precipitation were investigated from sixty-three observation stations. The Seasonality Precipitation means the degree of the precipitation falling intensively for some specific months. Spatially, precipitation that has a strong characteristic of regional shower is defined as seasonal precipitation. Precipitation forms are changed with various reasons and mainly the sporadic and local shower precipitation after rain spell in summer. Especially there appears a tendency that this kind of precipitation is sharply increasing in 1990's. Seasonality Index is used as a method to understand seasonal precipitation. If the yearly rainfall is concentrated for some specific months, Seasonality Index is growing gradually. It is confirmed that there is a tendency that all the from sixty-two observation stations Seasonality Index. While Seasonality Index over South of Korea concentrated from June to August because of the summer rain spell in the past ($1973{\sim}1982$), there appears to be a tendency that it concentrated from August and September since the mid 1990's. From the analysis of seasonal precipitation intensity distribution, most of southern Korea is under seasonality precipitation intensity 4. The seasonality precipitation intensity classification results are as follow: most of the observation stations were on a scale intensity of 3 and 4 in the past but currently reads seasonality precipitation intensities of 5 and 6.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.12 no.4
• /
• pp.44-55
• /
• 2013

Intelligent transportation systems allow us to have valuable opportunities for collecting reliable wide-area coverage traffic and weather data. Significant efforts have been made in many countries to apply these data. This study identifies the critical points for classifying rain intensity by analyzing the relationship between rainfall and the amount of speed reduction. Then, traffic prediction performance by rain intensity level is evaluated using relative errors. The results show that critical points are 0.4mm/5min and 0.8mm/5min for classifying rain intensity (slight, moderate, and heavy rain). The best prediction performance is observable when previous five-block speed data is used as inputs under normal weather conditions. On the other hand, previous two or three-block speed data is used as inputs under rainy weather conditions. The outcomes of this study support the development of more reliable traffic information for providing advanced traffic information service.