• Journal of Korea Water Resources Association
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• v.49 no.9
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• pp.749-759
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• 2016

The aim of this study is to apply and to evaluate the radar-based risk prediction algorithm for damage reduction by sudden localized heavy rain in urban areas. The algorithm is combined with three processes such as "detection of cumulonimbus convective cells that can cause a sudden downpour", "automatic tracking of the detected convective cells", and "risk prediction by considering the possibility of sudden downpour". This algorithm was applied to rain events that people were marooned in small urban stream. As the results, the convective cells were detected through this algorithm in advance and it showed that it is possible to determine the risk of the phenomenon of developing into local heavy rain. When use this risk predicted results for flood prevention operation, it is able to secure the evacuation time in small streams and be able to reduce the casualties.

• Journal of Korea Water Resources Association
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• v.53 no.4
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• pp.313-322
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• 2020

There is always a risk of water disasters due to sudden storms in mountainous regions in Korea, which is more than 70% of the country's land. In this study, a radar-based risk prediction technique for sudden downpour is applied in the mountainous region and is evaluated for its applicability using Mt. Biseul rain radar. Eight local heavy rain events in mountain regions are selected and the information was calculated such as early detection of cumulonimbus convective cells, automatic detection of convective cells, and risk index of detected convective cells using the three-dimensional radar reflectivity, rainfall intensity, and doppler wind speed. As a result, it was possible to confirm the initial detection timing and location of convective cells that may develop as a localized heavy rain, and the magnitude and location of the risk determined according to whether or not vortices were generated. In particular, it was confirmed that the ground rain gauge network has limitations in detecting heavy rains that develop locally in a narrow area. Besides, it is possible to secure a time of at least 10 minutes to a maximum of 65 minutes until the maximum rainfall intensity occurs at the time of obtaining the risk information. Therefore, it would be useful as information to prevent flash flooding disaster and marooned accidents caused by heavy rain in the mountainous area using this technique.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.2
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• pp.81-93
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• 2015

The comprehensive master plan in November 2010 on Saemangeum internal development has been released, and there is a need for complementary measures related to in-situ monitoring methods in order to acquire water temperature (T) and salinity (S) data. Thus, these data are monitored and analyzed by Korea Rural Community Corporation continuously. The purposes of current study are to evaluate the distributions of seasonal T and S, sigma-t, and stratification parameter and to compare annual stratification system in 2011 and 2012. To achieve these objectives, monthly vertical changes of T, S, and sigma-t, which are reproduced by a kriging technique, have been analyzed. In summer, the temperature difference between surface and bottom layers varies from 2 to $3^{\circ}C$, and the stratification of T is considerably weak. The stratification of S occurs abruptly within depth of EL. (-)5 to EL. (-)10 m. Therefore, stratification is induced by sudden increasing of water inflow amount due to a localized downpour during the rainy season, and these stratification processes are strongly influenced by inflowing a fresh water from watersheds in estuary environment.