• Title/Summary/Keyword: Flood area

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Application of the Artificial Neurons Networks for Runoff Forecasting in Sungai Kolok Basin, Southern Thailand

  • Mama, Ruetaitip;Namsai, Matharit;Choi, Mikyoung;Jung, Kwansue
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.259-259
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    • 2016
  • This study examined Artificial Neurons Networks model (ANNs) for forecast flash discharge at Southern part of Thailand by using rainfall data and discharge data. The Sungai Kolok River Basin has meant the border crossing between Thailand and Malaysia which watershed drains an area lies in Thailand 691.88 square kilometer from over all 2,175 square kilometer. The river originates in mountainous area of Waeng district then flow through Gulf of Thailand at Narathiwat Province, which the river length is approximately 103 kilometers. Almost every year, flooding seems to have increased in frequency and magnitude which is highly non-linear and complicated phenomena. The purpose of this study is to forecast runoff on Sungai Kolok at X.119A gauge station (Sungai Kolok district, Narathiwat province) for 3 days in advance by using Artificial Neural Networks model (ANNs). 3 daily rainfall stations and 2 daily runoff station have been measured by Royal Irrigation Department and Meteorological Department during flood period 2000-2014 were used as input data. In order to check an accuracy of forecasting, forecasted runoff were compared with observed data by pursuing Coefficient of determination ($R^2$). The result of the first day gets the highest accuracy and then decreased in day 2 and day 3, consequently. $R^2$values for first day, second day and third day of runoff forecasting is 0.71, 0.62 and 0.49 respectively. The results confirmed that the ANNs model can be used when the range of collected dataset is short and real-time operated. In conclusion, the ANNs model is suitable to runoff forecasting during flood incident of Sungai Kolok river because it is straightforward model and require with only a few parameters for simulation.

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Development of an outline project cost calculation module for disaster prevention facilities in the living area due to winds and floods (풍수해 생활권 방재시설에 대한 개략 사업비 산정 모듈 개발)

  • Kim, Sol;Lee, Dong Seop;Lee, Jong Jin
    • Journal of Korea Water Resources Association
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    • v.56 no.1
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    • pp.45-52
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    • 2023
  • Due to natural disasters such as heavy rain that occurred in the metropolitan area in August 2022, human casualties and property damage are increasing. Accordingly, the government is making efforts to respond to natural disasters, but due to the absence of related standards and standardized standards, problems such as increased construction costs and deterioration in construction quality for disaster prevention facility maintenance projects are occurring. Accordingly, a rough construction cost estimation module was developed and applied to 25 new pumping stations in Korea. As a result of the analysis, the accuracy of the rough construction cost derived through the module recorded 70% of the detailed design cost, which is 4% higher than the previously used rough construction cost accuracy of 66% by the Ministry of Environment. Accordingly, it is expected that the efficiency of the disaster prevention project can be increased if the developed module is used to calculate the rough construction cost for storm and flood disaster prevention in the future.

Dilemma of a small dam with large basin area under climate change condition

  • Jeong-Hyeok Ma;Chulsang Yoo;Tae-Sup Yun;Dongwhi Jung
    • Computers and Concrete
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    • v.33 no.5
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    • pp.559-572
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    • 2024
  • Problems of under-sized dams (small dams with large basin area) could get worse under the global warming condition. This study evaluates the possible change of these problems with the Namgang Dam, an under-sized dam in Korea. For this purpose, first, this study simulates the dam inflow data using a rainfall-runoff model, which are then used as input for the reservoir operation. As a result, daily dam storage, dam release, and dam water supply are derived and compared for both past observed period (1973~2022) and future simulated period (2006~2099) based on the global warming scenarios. Summarizing the results are as follows. First, the inflow rate in the future is expected to be increased significantly. The maximum inflow could be twice of that observed in the past. As a result, it is also expected that the frequency of the water level reaching the high level is increasing. Also, the amount and frequency of dam release are to be increased in the future period. More seriously, this increase is expected to be concentrated on rather extreme cases with large dam release volume. Simply, the condition for flood protection in the downstream of the Namgang Dam is becoming worse and worse. Ironically, the severity of water shortage problem is also expected to become much worse. As the most extreme case, the frequency of no water supply was zero in the observed period, but in the future period, it becomes once every five years. Both the maximum consecutive shortage days and the total shortage volume are expected to become more than twice in the future period. To prevent or mitigate this coming problem of an under-sized dam, the only countermeasure at this moment seems to be its redevelopment. Simply a bigger dam with larger dam reservoir can handle this adverse effect more easily.

Quantitative Precipitation Estimation using High Density Rain Gauge Network in Seoul Area (고밀도 지상강우관측망을 활용한 서울지역 정량적 실황강우장 산정)

  • Yoon, Seong-sim;Lee, Byongju;Choi, Youngjean
    • Atmosphere
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    • v.25 no.2
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    • pp.283-294
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    • 2015
  • For urban flash flood simulation, we need the higher resolution radar rainfall than radar rainfall of KMA, which has 10 min time and 1km spatial resolution, because the area of subbasins is almost below $1km^2$. Moreover, we have to secure the high quantitative accuracy for considering the urban hydrological model that is sensitive to rainfall input. In this study, we developed the quantitative precipitation estimation (QPE), which has 250 m spatial resolution and high accuracy using KMA AWS and SK Planet stations with Mt. Gwangdeok radar data in Seoul area. As the results, the rainfall field using KMA AWS (QPE1) is showed high smoothing effect and the rainfall field using Mt. Gwangdeok radar is lower estimated than other rainfall fields. The rainfall field using KMA AWS and SK Planet (QPE2) and conditional merged rainfall field (QPE4) has high quantitative accuracy. In addition, they have small smoothed area and well displayed the spatial variation of rainfall distribution. In particular, the quantitative accuracy of QPE4 is slightly less than QPE2, but it has been simulated well the non-homogeneity of the spatial distribution of rainfall.

Study of Littoral Sand Migration Along the West Coast of Ahnmyeon Island, Korea

  • Park, Yong Ahn
    • 한국해양학회지
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    • v.10 no.1
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    • pp.1-6
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    • 1975
  • A marine geological investigation of the glass sand deposit in the beach along the west coast of Ahnmyeon Island, South Chung Cheong Province, Korea was carried out to solve the problen of sand material migration, textural properties of the sands and the glass sand reserve for future exploitation. Several bos coring analyses by means of the internal sedimentary structure.i.e., cross- stratification show significantly that most sands are moving and accumulation along the mean vector direction of $N20^{\circ}E-N60^{\circ}$ E in the area investigated. The average mean size of the sand sediments in the area studied ranges from 0.212mm to 0.275mm. The mechanism of sand migration in the area is considered to be interplay between longshore drift and flood tidal current. The sorting value of the sands ranges from 0.24 to 0.50. Therefore, these sand sediments are characteristic to be "well sorted". The average chemical composition of the glass sand in the area is the following: $SiO\_2$:-90.8%, $Al_2O_3$: -2.18%, $Fe_2O_3$:-0.73%, CaO:-1.79. The binocular microscope examination of the sands show that most of the sands are characteristically ice- clear quartz in mineral composition and their count percentage is mostly 92% or 96%.

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Estimation of Probable Maximum Precipitation in Thailand Using Geographic Information System

  • Kingpaiboon, Sununtha;Netwong, Titiya
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.804-806
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    • 2003
  • Probable Maximum Precipitation (PMP) is essential in the design of hydraulic structures such as dams, weirs and flood control structures. Up to the present, PMP has been derived from any proper single storm which can have a large error. PMP values should be evaluated from many historic heavy storm events from all over the country. Since this can be done at the spots of storm occurring and the calculated PMP from all spots in the country can be correlated. The objectives of this study are therefore to evaluate PMP from historic heavy storm data from 1972 to 2000 by using meteorological method, then to correlate and to present the results using GIS. The maximized rainfall depths can be calculate from depth of heavy rainfall and dew point temperature, and then can be analyzed for each rainfall duration to obtain spatial rainfall distribution by using GIS. The depth-area-duration relationship of maximized rainfall can be obtained and this helps to develop enveloped curves . The results from this study are a set of contour maps of PMP for each rainfall duration for all over the country and the depth-area-duration relationships for the area of 100 to 50,000 km.$^{2}$ at duration of 1, 2 and 3 days.

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Assessment of Feasibility of Rainfall-Runoff Simulation Using SRTM-DEM Based on SWMM (SWMM 기반 SRTM-DEM을 활용한 강우-유출 모의 가능성 평가)

  • Mirae Kim;Junsuk Kang
    • 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.

The Variation of Current by the Building of Artificial Upwelling Structure ( I ) (인공용승구조물 설치에 의한 유동변화 ( I ))

  • Kim, Dong-Sun;Hwang, Suk-Bum
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.12 no.4 s.27
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    • pp.301-306
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    • 2006
  • In order to estimate the characteristics of water movements around artificial upwelling structure, current measurements were carried out along lines E-W and S-N on May 4th(neap tide} and May 30th(spring tide), 2006. In the study area, southeastward flow was dominant during the field observations, and the pattern of water movement in the upper layer above 30m depth was different from that in the lower layer below 30m depth Vertical flow(w-component} around the artificial structure area and western area was shown to be upward flow, but downward flow occurred in the southern, northern and eastern parts at the neap tide. At the spring tide, the ebb current along E-W line showed upwelling flow in the eastern part and western area and showed upwelling flow near the artificial structure area and downwelling flow far away that one. At the spring tide, upward flow was dominant along S-N line during the flood current Volume transport by upward flow was higher than that by downward flow. Volume transport by upward flow during ebb of neap tide was greater than during flood current of neap tide, but was reverse at the spring tide.

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Comparison and State Analysis of Slope Management System(SMS) at Home and Aboard (국내외 사면관리시스템의 비교 및 현황분석)

  • Kang, Ho-Yun;Jang, Yong-Gu;Hong, Soon-Hun;Kang, In-Joon
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.403-408
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    • 2007
  • Korea is topographically and meteorologically prone to natural disasters. In addition to extraordinary weather, localized heavy rain is a irregular occurrence. Korea are frequently damaged by rain, wind, flood, etc. Recently, slope failures are disastrous when they occur in mountainous area adjoining highways. The accidents associated with slope failures have increased due to rapid urbanization of mountainous area. Therefore, the inspection of slope is conducted to maintain highway safety as well as road function. We developed basic function and risk management of a partial shape on highway slopes based on the internet. It is important for quantitative risk evaluation of highway slopes.

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Dynamic Simulation of Storm Surge and Storm Water-Combine Inundation on the Jeju Coastal Area (폭풍 해일 및 폭풍우로 인한 제주 해안역에서의 동역학적 범람 모의)

  • Lee, Jung-Lyul;Lee, Byung-Gul;Lee, Joo-Yong;Lim, Heung-Soo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.1945-1949
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    • 2006
  • A storm-induced coastal inundation model (SICIM) is presented to simulate the flood event during typhoon passage that often results in significant rise in sea-level heights especially in the upstream region of the basin. The SICIM is a GIS-based distributed hydrodynamic model, both storm surge and storm water inundations are taken into account. The spatial and temporal distribution of the storm water level and flux are calculated. The model was applied to Jeju Island since it has an isolated watershed that is easy to handle as a first step of model application. Another reason is that it is surrounded by coastal area exposed to storm surge inundation. The model is still advancing and will be the framework of a predictive early inundation warning system.

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