• Title/Summary/Keyword: rainfall data

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Restoration of 18 Years Rainfall Measured by Chugugi in Gongju, Korea during the 19th Century (19세기 공주감영 측우기 강우량 18년 복원)

  • Boo, Kyung-On;Kwon, Won-Tae;Kim, Sang-Won;Lee, Hyon-Jung
    • Atmosphere
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    • v.16 no.4
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    • pp.343-350
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    • 2006
  • The rainfall amount measured by Chugugi at Gongju was found in "Gaksadeungnok". Gaksadeungnok is ancient documents from governmental offices in Joseon dynasty. Rainfall data at Gongju are restored for 18 years of 19th century. In 1871, total rainfall amount is 1,338 mm. It is different by about 11% in the amount compared with Seoul Chugugi rainfall in 1871 and Daejeon modern raingauge measurement result during the 30 years (1971-2000). Annual march of monthly rainfall data at Gongju is similar with that of Seoul. Based on the results, restored rainfall at Gongju is consistent with Seoul Chugugi rainfall data. The rainfall amount restored in this study is measured by Chugugi which was installed at Gongju, in Chung-Cheong province. Furthermore, Gaksadeungnok includes rainfall amount reports by agricultural tool measurement in addition to Chugugi measurement. These facts prove a network of rain gauge in Joseon dynasty.

A Study on the Regionalization of Point Rainfall by Multivariate Analysis Technique (다변량 분석기법에 의한 지점강우의 권역화 연구)

  • Park, Sang-Woo;Jun, Byong-Ho;Jang, Suk-Hwan
    • Journal of Korea Water Resources Association
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    • v.36 no.5
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    • pp.879-892
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    • 2003
  • This study has performed the regionalization of point rainfall which has the hydrological homogeneity for regional frequency analysis of the rainfall. For the study, the recorded rainfall data were collected from 60 rainfall gauge stations distributed all over country of the Korea Meteorological Administration, and 32 rainfall characteristic elements were analyzed from the collected data. Using the principal component analysis to be data reduction technique of the multivariate analysis and the cluster analysis to be grouping technique about many of rainfall characteristic elements of each station, the regionalization of point rainfall was accomplished rationally and efficiently. As the result, hydrological homogeneous regions of point rainfall were divided by 5 regions and 3 other regions, and rainfall characteristics of divided each region were analyzed and compared relatively using regional mean values of each rainfall element data.

Characteristics of Rainfall Thresholds for the Initiation of Landslides at Chuncheon Province (춘천시에서 발생한 산사태 유발강우의 특성 분석)

  • Sang Ug, Kim;Kyong Oh, Baek
    • Journal of the Korean Society of Safety
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    • v.37 no.6
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    • pp.148-157
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    • 2022
  • Every year, particularly during the monsoon rainy season, landslides at the Chuncheon province of South Korea cause tremendous damage to lives, properties, and infrastructures. More so, the high rainfall intensity and long rainfall days that occurred in 2020 have increased the water content in the soil, thereby increasing the chances of landslide occurrences. Besides this, the rainfall thresholds and characteristics responsible for the initiation of landslides in this region have not been properly identified. Therefore, this paper addresses the rainfall thresholds responsible for the initiation of landslides at Chuncheon from a regional perspective. Using data obtained from rainfall measurements taken from 2002 to 2011, we identify a threshold relationship between rainfall intensity and rainfall duration for the initiation of landslides. In addition, we identify the relationship between the rainfall intensity using a 3-day, 7-day, and 10-day antecedent rainfall observation. Specifically, we estimate the rainfall data at 8 sites where debris flow occurred in 2011 by kriging. Following this, the estimated data are used to construct the relationship between the intensity (I), duration (D), and frequency (F) of rainfall. The results of the intensity-duration-frequency (IDF) analysis show that landslides will occur under a rainfall frequency below a 2-year return period at two areas in Chuncheon. These results will be effectively used to design structures that can prevent the occurrence of landslides in the future.

Bias-correction of Dual Polarization Radar rainfall using Convolutional Autoencoder

  • Jung, Sungho;Le, Xuan Hien;Oh, Sungryul;Kim, Jeongyup;Lee, GiHa
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.166-166
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    • 2020
  • Recently, As the frequency of localized heavy rains increases, the use of high-resolution radar data is increasing. The produced radar rainfall has still gaps of spatial and temporal compared to gauge observation rainfall, and in many studies, various statistical techniques are performed for correct rainfall. In this study, the precipitation correction of the S-band Dual Polarization radar in use in the flood forecast was performed using the ConvAE algorithm, one of the Convolutional Neural Network. The ConvAE model was trained based on radar data sets having a 10-min temporal resolution: radar rainfall data, gauge rainfall data for 790minutes(July 2017 in Cheongju flood event). As a result of the validation of corrected radar rainfall were reduced gaps compared to gauge rainfall and the spatial correction was also performed. Therefore, it is judged that the corrected radar rainfall using ConvAE will increase the reliability of the gridded rainfall data used in various physically-based distributed hydrodynamic models.

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Data Transformation and Display Technique for 3D Visualization of Rainfall Radar (강우레이더의 3차원 가시화를 위한 데이터 변환 및 표출기법)

  • Kim, Hyeong Hun;Park, Hyeon Cheol;Choi, Yeong Cheol;Kim, Tae Su;Choung, Yun Jae
    • Journal of Korea Multimedia Society
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    • v.20 no.2
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    • pp.352-362
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    • 2017
  • This paper proposes an algorithm for automatically converting and displaying rainfall radar data on a 3D GIS platform. The weather information displayed like rainfall radar data is updated frequently and large-scale. Thus, in order to efficiently display the data, an algorithm to convert and output the data automatically, rather than manually, is required. In addition, since rainfall data is extracted from the space, the use of the display image fused with the 3D GIS data representing the space enhances the visibility of the user. To meet these requirements, this study developed the Auto Data Converter application that analyzes the raw data of the rainfall radar and convert them into a universal format. In addition, Unity 3D, which has good development accessibility, was used for dynamic 3D implementation of the converted rainfall radar data. The software applications developed in this study could automatically convert a large volume of rainfall data into a universal format in a short time and perform 3D modeling effectively according to the data conversion on the 3D platform. Furthermore, the rainfall radar data could be merged with other GIS data for effective visualization.

A Selection of the Point Rainfall Process Model Considered on Temporal Clustering Characteristics (시간적 군집특성을 고려한 강우모의모형의 선정)

  • Kim, Kee-Wook;Yoo, Chul-Sang
    • Journal of Korea Water Resources Association
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    • v.41 no.7
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    • pp.747-759
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    • 2008
  • This study, a point rainfall process model, which could represent appropriately observed rainfall data, was to select. The point process models-rectangular pulses Poisson process model(RPPM), Neyman-Scott rectangular pulses Poisson process model(NS-RPPM), and modified Neyman-Scott rectangular pulses Poisson process model(modified NS-RPPM)-all based on Poisson process were considered as possible rainfall models, whose statistical analyses were performed with their simulation rainfall data. As results, simulated rainfall data using the NS-RPPM and the modified NS-RPPM represent appropriately statistics of observed data for several aggregation levels. Also, simulated rainfall data using the modified NS-RPPM shows similar characteristics of rainfall occurrence to the observed rainfall data. Especially, the modified NS-RPPM reproduces high-intensity rainfall events that contribute largely to occurrence of natural harzard such as flood and landslides most similarly. Also, the modified NS-RPPM shows the best results with respect to the total rainfall amount, duration, and inter-event time. In conclusions, the modified NS-RPPM was found to be the most appropriate model for the long-term simulation of rainfall.

Rainfall Intensity Estimation with Cloud Type using Satellite Data

  • Jee, Joon-Bum;Lee, Kyu-Tae
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.660-663
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    • 2006
  • Rainfall estimation is important to weather forecast, flood control, hydrological plan. The empirical and statistical methods by measured data(surface rain gauge, rainfall radar, Satellite) is commonly used for rainfall estimation. In this study, the rainfall intensity for East Asia region was estimated using the empirical relationship between SSM/I data of DMSP satellite and brightness temperature of GEOS-9(10.7${\mu}m$) with cloud types(ISCCP and MSG classification). And the empirical formula for rainfall estimation was produced by PMM (Probability Matching Method).

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Multivariate Time Series Analysis for Rainfall Prediction with Artificial Neural Networks

  • Narimani, Roya;Jun, Changhyun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.135-135
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    • 2021
  • In water resources management, rainfall prediction with high accuracy is still one of controversial issues particularly in countries facing heavy rainfall during wet seasons in the monsoon climate. The aim of this study is to develop an artificial neural network (ANN) for predicting future six months of rainfall data (from April to September 2020) from daily meteorological data (from 1971 to 2019) such as rainfall, temperature, wind speed, and humidity at Seoul, Korea. After normalizing these data, they were trained by using a multilayer perceptron (MLP) as a class of the feedforward ANN with 15,000 neurons. The results show that the proposed method can analyze the relation between meteorological datasets properly and predict rainfall data for future six months in 2020, with an overall accuracy over almost 70% and a root mean square error of 0.0098. This study demonstrates the possibility and potential of MLP's applications to predict future daily rainfall patterns, essential for managing flood risks and protecting water resources.

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The Effects of Typhoon Initialization and Dropwindsonde Data Assimilation on Direct and Indirect Heavy Rainfall Simulation in WRF model

  • Lee, Ji-Woo
    • Journal of the Korean earth science society
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    • v.36 no.5
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    • pp.460-475
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    • 2015
  • A number of heavy rainfall events on the Korean Peninsula are indirectly influenced by tropical cyclones (TCs) when they are located in southeastern China. In this study, a heavy rainfall case in the middle Korean region is selected to examine the influence of typhoon simulation performance on predictability of remote rainfall over Korea as well as direct rainfall over Taiwan. Four different numerical experiments are conducted using Weather Research and Forecasting (WRF) model, toggling on and off two different improvements on typhoon in the model initial condition (IC), which are TC bogussing initialization and dropwindsonde observation data assimilation (DA). The Geophysical Fluid Dynamics Laboratory TC initialization algorithm is implemented to generate the bogused vortex instead of the initial typhoon, while the airborne observation obtained from dropwindsonde is applied by WRF Three-dimensional variational data assimilation. Results show that use of both TC initialization and DA improves predictability of TC track as well as rainfall over Korea and Taiwan. Without any of IC improvement usage, the intensity of TC is underestimated during the simulation. Using TC initialization alone improves simulation of direct rainfall but not of indirect rainfall, while using DA alone has a negative impact on the TC track forecast. This study confirms that the well-suited TC simulation over southeastern China improves remote rainfall predictability over Korea as well as TC direct rainfall over Taiwan.

An intercomparison of GMS image data and observed rainfall data (GMS 영상자료와 관측강수량 자료의 비교)

  • 서애숙;이미선;김금란;이희훈
    • Korean Journal of Remote Sensing
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    • v.10 no.1
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    • pp.1-14
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    • 1994
  • The purpose of this study is to find the relationship between GMS image data and hourly observed rainfalls data. Heavy rainfall cases over South Korea on 10th September 1990 and on 29th July 1993 were selected for studying of the relationship between the image data and reinfalls. First, image data were converted to TBB(Temperature of Black Body) and albedo and then these values were extracted for the pixels closest to the surface observation station to correlate with the rainfall data. Horizontal distribution of TBB and albedo tells roughly rainfall regions. The correlation between rainfall and TBB is found to be very low in quantitative analysis. The weak relationship between the brighter albedo and the higher rainfall probability is observed. This study suggests that the TBB values are useful in classifying rain areas and for heavy rainfalls the albedo values are more useful than the TBB. Low linear correlation between the fields may be attributed to the neglect of cloud types in this study.