• Title/Summary/Keyword: heavy localized rainfall

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Sensitivities of WRF Simulations to the Resolution of Analysis Data and to Application of 3DVAR: A Case Study (분석자료의 분해능과 3DVAR 적용에 따른 WRF모의 민감도: 사례 연구)

  • Choi, Won;Lee, Jae Gyoo;Kim, Yu-Jin
    • Atmosphere
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    • v.22 no.4
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    • pp.387-400
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    • 2012
  • This study aims at examining the sensitivity of numerical simulations to the resolution of initial and boundary data, and to an application of WRF (Weather Research and Forecasting) 3DVAR (Three Dimension Variational data Assimilation). To do this, we ran the WRF model by using GDAS (Global Data Assimilation System) FNL (Final analyses) and the KLAPS (Korea Local Analysis and Prediction System) analyses as the WRF's initial and boundary data, and by using an initial field made by assimilating the radar data to the KLAPS analyses. For the sensitivity experiment, we selected a heavy rainfall case of 21 September 2010, where there was localized torrential rain, which was recorded as 259.5 mm precipitation in a day at Seoul. The result of the simulation using the FNL as initial and boundary data (FNL exp) showed that the localized heavy rainfall area was not accurately simulated and that the simulated amount of precipitation was about 4% of the observed accumulated precipitation. That of the simulation using KLAPS analyses as initial and boundary data (KLAPC exp) showed that the localized heavy rainfall area was simulated on the northern area of Seoul-Gyeonggi area, which renders rather difference in location, and that the simulated amount was underestimated as about 6.4% of the precipitation. Finally, that of the simulation using an initial field made by assimilating the radar data to the KLAPS using 3DVAR system (KLAP3D exp) showed that the localized heavy rainfall area was located properly on Seoul-Gyeonggi area, but still the amount itself was underestimated as about 29% of the precipitation. Even though KLAP3D exp still showed an underestimation in the precipitation, it showed the best result among them. Even if it is difficult to generalize the effect of data assimilation by one case, this study showed that the radar data assimilation can somewhat improve the accuracy of the simulated precipitation.

Concentration Rise of Fine Particle according to Resuspended Dust from Paved Roads after Sudden Heavy Rain in Busan (부산 도심지역 기습 폭우 후 형성된 도로면 토사의 재비산에 의한 미세먼지 농도 상승)

  • Jeon, Byung-Il
    • Journal of Environmental Science International
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    • v.25 no.5
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    • pp.705-713
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    • 2016
  • This study investigates the concentration sudden rise in fine particle according to resuspended dust from paved roads after sudden heavy rain in Busan on August 25, 2015. The localized torrential rainfall in Busan area occurred as tropical airmass flow from the south and polar airmass flow from north merged. Orographic effect of Mt. Geumjeong enforced rainfall and it amounted to maximum 80 mm/hr at Dongrae and Geumjeong region in Busan. This heavy rain induced flood and landslide in Busan and the nearby areas. The sudden heavy rain moved soil and gravel from mountainous region, which deposited on paved roads and near roadside. These matters on road suspended by an automobile transit, and increased fine particle concentration of air. In addition outdoor fine particle of high concentration flowed in indoor by shoes, cloths and air circulation.

A Case Study on Disaster and Characteristics of Debris Flows by Heavy Localized Rainfall of Gangwon Areas in July, 2006 (2006년 강원지역 토석류의 특성과 피해현황분석)

  • Song, Pyung-Hyun;You, Byung-Ok;Jung, Chan-Gyu;Ahn, Kwang-kuk;Lee, Cheo-kun
    • 기술발표회
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    • s.2006
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    • pp.146-155
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    • 2006
  • A study for damage degree and reduction programs of disaster was performed after collecting and analyzing the damage data by the type of flood damage resulting from the localized rainfall Gangwon area has been damaged by heavy localized rainfall between July 15 and 17 in 2006 Specially, a number of people was killed and much properties were lost in Inje, Yangyang and Pyeongchang area Recently, the damages by debris flow has been increased more than any other disaster causes, because heavy rainfall closed to about 100mm/hr by global warming in short time has been developed frequently. In other words, an area forming a highland has a potential debris flow Therefore, in this study, the damages data by debris flow in the area of Inje and Yangyang were collected and analyzed to consider the type of flood damage In future, it must be tried to find a complementary solution and establishing management system for debris flow when the civil construction begins

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Effects of Habitat Changes Caused by Localized Heavy Rain on the Distribution of Benthic Macroinvertebrates (집중호우에 의한 서식지변동이 저서성 대형무척추동물의 분포에 미치는 영향)

  • Kim, Hyoung-Gon;Yoon, Chun-Sik;Cheong, Seon-Woo
    • Journal of Environmental Science International
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    • v.27 no.8
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    • pp.689-699
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    • 2018
  • The changes on community structures of benthic macroinvertebrates, relevance to the environment and interrelationship between benthos were studied over two years in stream with large environmental disturbance, which caused by localized heavy rain during Typhoon Chaba in October 2016. As a result, the number of species and individuals were increased after localized heavy rain, especially numbers of individuals of Ephemeroptera and Plecoptera were greatly increased. On the contrary, those of Semisulcospira libertina and Semisulcospira forticosta of Mesogastropoda were greatly decreased. Dominant species was Baetis fuscatus of Ephemeroptera, numbers of species and individuals of Ephemeroptera, Plecoptera and Trichoptera(EPT group) were dramatically increased from 26 species, 110 individuals to 32 species, 365 individuals respectively. This suggests that the change of river bed and flow velocity due to heavy rain provided a suitable environment for the EPT group that preferred the rift of a stream. In the functional feeding group, only gathering collectors and filtering collectors were identified in autumn of 2017 because some functional groups preferentially adapted to the changed environment. The interspecific competition and environmental condition were the worst in autumn after heavy rain due to the increase individuals of some species. The ecological score of benthic macroinvertebrate community(ESB) was higher after the heavy rain than before. Results of the Group Pollution Index(GPI), Korean Saprobic Index(KSI) and Benthic Macroinvertebrate Index(BMI) were similar to those before and after heavy rainfall. Therefore, ESB was the most discriminating method for estimating the biological water quality in this study. Some species that are sensitive to water quality changes still appear or increase individuals in the area under investigation after the heavy rain. On the other hand, the individuals of some pollutant species decreased. This is thought to be because the habitat fluctuation caused by heavy rainfall has improved the water environment.

An Improvement Study on the Hydrological Quantitative Precipitation Forecast (HQPF) for Rainfall Impact Forecasting (호우 영향예보를 위한 수문학적 정량강우예측(HQPF) 개선 연구)

  • Yoon Hu Shin;Sung Min Kim;Yong Keun Jee;Young-Mi Lee;Byung-Sik Kim
    • Journal of Korean Society of Disaster and Security
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    • v.15 no.4
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    • pp.87-98
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    • 2022
  • In recent years, frequent localized heavy rainfalls, which have a lot of rainfall in a short period of time, have been increasingly causing flooding damages. To prevent damage caused by localized heavy rainfalls, Hydrological Quantitative Precipitation Forecast (HQPF) was developed using the Local ENsemble prediction System (LENS) provided by the Korea Meteorological Administration (KMA) and Machine Learning and Probability Matching (PM) techniques using Digital forecast data. HQPF is produced as information on the impact of heavy rainfall to prepare for flooding damage caused by localized heavy rainfalls, but there is a tendency to overestimate the low rainfall intensity. In this study, we improved HQPF by expanding the period of machine learning data, analyzing ensemble techniques, and changing the process of Probability Matching (PM) techniques to improve predictive accuracy and over-predictive propensity of HQPF. In order to evaluate the predictive performance of the improved HQPF, we performed the predictive performance verification on heavy rainfall cases caused by the Changma front from August 27, 2021 to September 3, 2021. We found that the improved HQPF showed a significantly improved prediction accuracy for rainfall below 10 mm, as well as the over-prediction tendency, such as predicting the likelihood of occurrence and rainfall area similar to observation.

Adjustment of Radar Precipitation Estimation Based on the Local Gauge Correction Method (국지 우량계 보정 방법을 이용한 레이더 강우 조정)

  • Kim, Kwang-Ho;Lee, Gyuwon;Kang, Dong-Hwan;Kwon, Byung-Hyuk;Han, Kun-Yeun
    • Journal of the Korean earth science society
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    • v.35 no.2
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    • pp.115-130
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    • 2014
  • The growing possibility of the disaster due to severe weather calls for disaster prevention and water management measures in South Korea. In order to prevent a localized heavy rain from occurring, the rainfall must be observed and predicted quantitatively. In this study, we developed an adjustment algorithm to estimate the radar precipitation applying to the local gauge correction (LGC) method which uses geostatistical effective radius of errors of the radar precipitation. The effective radius was determined from the errors of radar rainfall using geostatistical method, and we adjusted radar precipitation for four heavy rainfall events based on the LGC method. Errors were decreased by about 40% and 60% in adjusted hourly rainfall accumulation and adjusted total rainfall accumulation for four heavy rainfall events, respectively. To estimate radar precipitation for localized heavy rain events in summer, therefore, we believe that it was appropriate for this study to use an adjustment algorithm, developed herein.

Design of FPGA-based Signal Processing of EWRG for Localized Heavy Rainfall Observation (국지성 호우 관측을 위한 FPGA 기반의 전파강수계 신호처리 설계)

  • Choi, Jeong-Ho;Lee, Bae-Kyu;Park, Hyeong-Sam;Park, Jeong-Min;Lim, Sang-Hun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.9
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    • pp.1215-1223
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    • 2020
  • Recently, the number of natural disasters caused by inclement weather conditions such as localized heavy rainfall, Typhoon, etc. is increasing in Korea, which requires relevant prevention and water management measures. Rain gauges installed on the ground have strengths in continuously·directly measures ground precipitation but cannot provide accurate information on spatial precipitation distribution in the areas without the rain gauges. The present research has designed and developed an electromagnetic-based multi-purpose precipitation gauge(EWRG, Electromagnetic Wave Rain Gauge) that can measure rainfall at the real time, by overcoming spatial representativeness. In this paper, we propose an FPGA-based signal processing design method for EWRG. The signal processing of the EWRG was largely designed by calculating the ADC and DDC of the LFM waveform, pulse compression, correlation coefficient and estimating the precipitation parameter. In this study, the LFM waveform and pulse compressed signal were theoretically analyzed.

The study for water level estimation by rainfall intensity of the upper region in the han river (한강 상류유역의 강우강도에 따른 수위 예측 연구)

  • Choi, Han-Kuy;Choe, Hyun-jong;Baek, Hyo-Seon
    • Journal of Industrial Technology
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    • v.30 no.B
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    • pp.91-98
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    • 2010
  • Recently, there has been enormous damage due to river floodings caused by localized heavy rains. The direct discharge triggered by those torrential rains inflicts severe property damage on the residents of nearby areas. To minimize the possibility of river floodings in case of heavy rains and to predict the possible damage, the management of existing rainfall and water level observatories should be checked and prediction methods based on the characteristics of water usage and floodgate of nearby rivers must be further analyzed. Therefore, this research analyzed the water level change predictions on different spots with a regression equation of rainfall and water levels, using the observation data of the water level observatory in Jeongseon-gun, Gangwon Province and the rainfall observatory which are located on the upper region of the Han river.

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A Fundamental Study on Slope Stability Due to Filtering Condition of Embankment Material During Rain (성토재료의 필터링 조건이 사면 안정에 미치는 기초연구)

  • Kim, Sang-Hwan;Kim, Hak-Moon;Shin, Jong-Ho;Ko, Dong-Pil
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.419-426
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    • 2008
  • Recently, localized heavy rain due to "EL-LIO" was a kind of reason by risk of slope stability. In this paper, the behaviour of slope when localized heavy rain was studied. In order to perform this study experimental programs were performed. Experimental programs was checked filtering conditions for slope stability due to localized heavy rain. And then, investigated slope stability and fracture mechanism each other types. In the experimental study, performed changing filtering condition by embankment, through five fixing factors such as rainfall intensity, slope shape, geological condition, compaction energy and water content. According to the results of this study, behaviour of facture slope has made a shallow and narrow waterway. This waterway expanded base stone. In order to, suggested a system for slope stability examination.

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