• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.553-556
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• 2012

The interference among the rain radars and interference in the adjacent wireless station due to the spurious signals from the rain radar were analyzed in this paper. The rain radar measures the rain intensity using S-band signal. The measured data are utilized in forecasting the rainfall. The interference among the rain radars or in the adjacent wireless stations may be caused by the high output power of rain radar. Based on the propagation analysis of S band signal and the deduced interference protection ratio of rain radar, the interference due to the rain radar are analyzed. Also, the radiation spectrum characteristics of a rain radar are deduced from the caused interference effects by the spurious signals of the rain radar.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.100.2-100.2
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• 2009

• Journal of Environmental Science International
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• v.33 no.7
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• pp.443-452
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• 2024

The recent increase in impermeable surfaces due to urbanization and the occurrence of concentrated heavy rainfall events caused by climate change have led to an increase in urban flooding. To predict and prepare for flood damage, a convenient and highly accurate simulation of rainfall-runoff based on geospatial information is essential. In this study, the storm water management model (SWMM) was applied to simulate rainfall runoff in the Bangbae-dong area of Seoul, using two sets of topographical data: The conventional topographic digital elevation model (TOPO-DEM) and the proposed shuttle radar topography mission (SRTM)-DEM. To evaluate the applicability of the SRTM-DEM for rainfall-runoff modeling, two DEMs were constructed for the study area, and rainfall-runoff simulations were performed. The construction of the terrain data for the study area generally reflected the topographical characteristics of the area. Quantitative evaluation of the rainfall-runoff simulation results indicated that the outcomes were similar to those obtained using the existing TOPO-DEM. Based on the results of this study, we propose the use of SRTM-DEM, a more convenient terrain data, in rainfall-runoff studies, rather than asserting the superiority of a specific geospatial data.

• Atmosphere
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• v.18 no.4
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• pp.317-338
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• 2008

Analyses of observational data and numerical simulations were performed to understand the mechanism of MCSs (Mesoscale Convective Systems) occurred on 13-14 July 2004 over Jindo area of the Korean Peninsula. Observations indicated that synoptic environment was favorable for the occurrence of heavy rainfall. This heavy rainfall appeared to have been enhanced by convergence around the Changma front and synoptic scale lifting. From the analyses of storm environment using Haenam upper-air observation data, it was confirmed that strong convective instability was present around the Jindo area. Instability indices such as K-index, SSI-index showed favorable condition for strong convection. In addition, warm advection in the lower troposphere and cold advection in the middle troposphere were detected from wind profiler data. The size of storm, that produced heavy rainfall over Jindo area, was smaller than $50{\times}50km^2$ according to radar observation. The storm developed more than 10 km in height, but high reflectivity (rain rate 30 mm/hr) was limited under 6 km. It can be judged that convection cells, which form cloud clusters, occurred on the inflow area of the Changma front. In numerical simulation, high CAPE (Convective Available Potential Energy) was found in the southwest of the Korean Peninsula. However, heavy rainfall was restricted to the Jindo area with high CIN (Convective INhibition) and high CAPE. From the observations of vertical drop size distribution from MRR (Micro Rain Radar) and the analyses of numerically simulated hydrometeors such as graupel etc., it can be inferred that melted graupels enhanced collision and coalescence process of heavy precipitation systems.

• Journal of information and communication convergence engineering
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• v.4 no.1
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• pp.41-45
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• 2006

A disdrometer has been used to determine Z-R relationships for the weather radar, which is unique coastal radar operating regularly in western tropical south Atlantic. Rainfall rates were divided into the stratiform rain and the convective rain on the basis of $10\;mm\;h^{-1}$. The Z-R relationship for the stratiform class was similar to the general one since the convective clouds did not developed and two classes of the rain rate were mixed.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1145-1149
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• 2006

The typhoon Rusa passed through the Korean peninsula from the west-southern part to the east-northern part in the summer season of 2002. The flash flood due to the Rusa was occurred over the Korean peninsula and especially the damage was concentrated in Kangnung, Yangyang, Kosung, and Jeongsun areas of Kangwon-Do. Since the latter half of the 1990s the flash flood has became one of the frequently occurred natural disasters in Korea. Flash floods are a significant threat to lives and properties. The government has prepared against the flood disaster with the structural and nonstructural measures such as dams, levees, and flood forecasting systems. However, since the flood forecasting system requires the rainfall observations as the input data of a rainfall-runoff model, it is not a realistic system for the flash flood which is occurred in the small basins with the short travel time of flood flow. Therefore, the flash flood forecasting system should be constructed for providing the realistic alternative plan for the flash flood. To do so, firstly, Flash Flood Monitoring and Prediction (FFMP) Model must be developed suitable to Korea terrain. In this paper, We develop the FFMP model which is based on GIS, Radar techniques and hydro-geomorphologic approaches. We call it the F2MAP model. F2MAP model has three main components (1) radar rainfall estimation module for the Quantitative Precipitation Forecasts (QPF), (2) GIS Module for the Digital terrain analysis, called TOPAZ(Topographic PArametiZation), (3) hydrological module for the estimation of threshold runoff and Flash Flood Guidance(FFG). For the performance test of the model developed in this paper, F2MAP model applied to the Kangwon-Do, Korea, where had a severe damage by the Typhoon Rusa in August, 2002. The result shown that F2MAP model is suitable for the monitoring and the prediction of flash flood.

• Journal of Environmental Science International
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• v.33 no.1
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• pp.43-57
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• 2024

The possible experimental time for cloud seeding was analyzed in South Korea. Rain gauge and radar precipitation data collected from September 2017 to August 2022 in from the three main target stations of cloud seeding experimentation (Daegwallyeong, Seoul, and Boryeong) were analyzed. In this study, the assumption that rainfall and cloud enhancement originating from the atmospheric updraft is a necessary condition for the cloud seeding experiment was applied. First, monthly and seasonal means of the precipitation duration and frequency were analyzed and cloud seeding experiments performed in the past were also reanalyzed. Results of analysis indicated that the experiments were possible during a monthly average of 7,025 minutes (117 times) in Daegwallyeong, 4,849 minutes (81 times) in Seoul, and 5,558 minutes (93 times) in Boryeong, if experimental limitations such as the insufficient availability of aircraft is not considered. The seasonal average results showed that the possible experimental time is the highest in summer at all three stations, which seems to be owing to the highest precipitable water in this period. Using the radar-converted precipitation data, the cloud seeding experiments were shown to be possible for 970-1,406 hours (11-16%) per year in these three regions in South Korea. This long possible experimental time suggests that longer duration, more than the previous period of 1 hour, cloud seeding experiments are available, and can contribute to achieving a large accumulated amount of enhanced rainfall.

• Atmosphere
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• v.20 no.3
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• pp.333-341
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• 2010

The stratiform rain fraction is investigated in the tropical boreal winter Madden-Julian oscillation (MJO) and summer intraseasonal oscillation (ISO) using Tropical Rainfall Measuring Mission (TRMM) Precipitation Rader data for the 11-yr period from 1998 to 2008. Composite analysis shows that the MJO/ISO produces larger stratiform rain rate than convective rain rate for nearly all phases following the propagating MJO/ISO deep clouds, with the greatest stratiform rainfall amount when the MJO/ISO center is located over the central-eastern Indian Ocean and the western Pacific. The fraction of the intraseasonally filtered stratiform rainfall compared to total rainfall (i.e., convective plus stratiform rainfall) amounts to 53~56%, which is 13~16% larger than the stratiform rain fraction estimated for the same data on seasonal-to-annual time scales by Schumacher and Houze. This indicates that the MJO/ISO exhibits the organized rainfall process which is characterized by the shallow convection/heating at the incipient phase and the subsequent flare-up of strong deep convection, followed by the development of stratiform clouds at the upper troposphere.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.3
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• pp.52-67
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• 2008

Recently, frequent occurrence of flash floods caused by climactic change has necessitated prompt and quantitative prediction of precipitation. In particular, the usability of rainfall radar that can carry out real-time observation and prediction of precipitation behavior has increased. Moreover, the use of distributed hydrological model that enables grid level analysis has increased for an efficient use of rainfall radar that provides grid data at 1km resolution. The use of distributed hydrologic model necessitates grid-type spatial data about target basins; to enhance reliability of flood runoff simulation, the use of visible and precise data is necessary. In this paper, physically based $Vflo^{TM}$ model and ModClark, a quasi-distributed hydrological model, were used to carry out flood runoff simulation and comparison of simulation results with data from Imjin River Basin, two-third of which is ungauged. The spatial scope of this study was divided into the whole Imjin River basin area, which includes ungauged area, and Imjin River basin area in South Korea for which relatively accurate and visible data are available. Peak flow and lag time outputs from the two simulations of each region were compared to analyze the impact of uncertainty in topographical parameters and soil parameters on flood runoff simulation and to propose effective methods for flood runoff simulation in ungauged regions.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.225-229
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• 2005

이류모형을 이용한 단기예측 레이더 강우자료와 관측 레이더자료의 비교를 통하여 얻어진 예측오차를 분석하였다. 임의 시점까지의 예측오차 장에 나타나는 확률분포 형태와 공간적 상관성을 분석하여 이들 특성을 반영하는 추후의 예측오차 장을 모의할 수 있었다. 모의된 예측오차 장과 합성된 단기예측 강우 장은 이류모형을 이용한 예측에 따른 불확실성 을 추계학적으로 반영한 예측강우를 제공한다.