• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.1
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• pp.132-142
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• 2003

A significant deficiency of most computer models used for stream floodplain analysis, is that the locations of structures impacted by flood waters, such as roads, buildings, and bridges, cannot be effectively compared to the floodplain location. The purpose of this study is the integration of the HEC River Analysis System(HEC-RAS) with ArcView geographic information system to develop a regional model for floodplain determination and representation. Also this study presents to enable two- and three-dimensional floodplain mapping and analysis in the ArcView. The methodology is applied to a Yeoju of Kyunggi-do, located in South Han River Basin. A digital terrain model is synthesized from HEC-RAS cross-sectional data and a digital elevation model of the study area. The flood plain data developed in ArcView was imported into HEC-RAS where it was combined with the field surveyed channel data in order to construct full floodplain cross sections that reflected accurate channel and overbank data for the HEC-RAS model. The flood plain limits could be expressed more accurately on ArcView by using water level data to be computed in HEC-RAS program. The computed water surface elevations and information of cross-section must be manually plotted in order to delineate floodplains. The resulting of this study provided a good representation of the general landscape and contained additional detail within the stream channel. Overall, the results of the study indicate that GIS combined with HEC-RAS is proven to be very useful and efficient for the automatic generation of flood maps, and an effective environment for floodplain mapping and analysis.

• Atmosphere
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• v.30 no.2
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• pp.155-167
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• 2020

In order to produce more detailed and accurate information of river discharge and freshwater discharge, global high-resolution hydrodynamic model (CaMa-Flood) is applied to an operational land surface model of global seasonal forecast system. In addition, bias correction to grid runoff for the hydrodynamic model is attempted. CaMa-Flood is a river routing model that distributes runoff forcing from a land surface model to oceans or inland seas along continentalscale rivers, which can represent flood stage and river discharge explicitly. The runoff data generated by the land surface model are bias-corrected by using composite runoff data from UNH-GRDC. The impact of bias-correction on the runoff, which is spatially resolved on 0.5° grid, has been evaluated for 1991~2010. It is shown that bias-correction increases runoff by 30% on average over all continents, which is closer to UNH-GRDC. Two experiments with coupled CaMa-Flood are carried out to produce river discharge: one using this bias correction and the other not using. It is found that the experiment adapting bias correction exhibits significant increase of both river discharge over major rivers around the world and continental freshwater discharge into oceans (40% globally), which is closer to GRDC. These preliminary results indicate that the application of CaMa-Flood as well as bias-corrected runoff to the operational global seasonal forecast system is feasible to attain information of surface water cycle from a coupled suite of atmospheric, land surface, and hydrodynamic model.

• Journal of Korea Water Resources Association
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• v.31 no.4
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• pp.415-427
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• 1998

FIAS (Flood Inundation Analysis System) using Arc/Info is developed and applied to the South Han River basin. The DWOPER model is revised and expanded to handle simultaneous multiple overtopping and/or breaking and to estimate the inundation depth and extents. The model is applied to an actual levee overtopping case, which occurred on August 23~27, 1995 in the South Han River. Stage hydrographs inside and outside of the levee are compared, then inundated discharges from overbank spilling are computed. The Graphic User Interface is developed with AML(Arc/Info Macro Language). Two-and three-dimensional inundation maps by Arc/Info are presented. The computed inundation extends agree with observations in terms of inundation depth and flooded area. Keywords : River, Floodwave, Flood Inundation, Geographic Information System.

• Spatial Information Research
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• v.11 no.2
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• pp.155-170
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• 2003

Flood inundation analysis system using GIS has been developed to simulate inundation in airport drainage areas. The model developed in this study has been synthetically presented and constructed the preprocess for database construction and input data preparing through a graphic user interface, GUI system and the postprocess processing graphically output resulted in mainprocess analysis model linked GIS(ArcView/Avenue). The mainprocess analysis model was simulated in real phenomenon caused by inflow of storm sewer system by simulation flooding due to backwater effect and surcharged flow in storm sewer system by simulating interaction coupling the overland flow analysis model and storm sewer system analysis model. In the future, the flood inundation analysis system developed in this study will be a great contribution to systematic decision-making for establishing the flood-mitigation management and facilities improvement plan to flooding damage in airport.

• IE interfaces
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• v.21 no.4
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• pp.365-377
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• 2008

In this paper, for constructing the Korean Hazard Information System (KHIS), we conceptually design a hazard evaluation process. We first deal with a hazard evaluation process focused on flood hazard to give the most immense damage and loss. The hazard evaluation process is consist of a damage evaluation process and a loss evaluation process, and is used for transforming hazards from natural disasters into economic measures. The proposed process is developed based on the famous FEMA (Federal Emergency Management Agency)'s $HAZAS^{@MH}$methodology. We modify the FEMA's process to be mutually exclusive and collectively exhaustive, that is all losses from the hazards are included into the estimation process but the losses are not duplicated in the process. In addition to this, we define the loss process specifically by considering the characteristics from the hazard environments of Korea. We can expect that KHIS for evaluating economic losses from natural hazards can be developed based on the conceptual design for the economic loss evaluation process, and KHIS can be used as a useful tool for analyzing the feasibilities of mitigation plans in central/local governments.

• Spatial Information Research
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• v.12 no.3
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• pp.229-237
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• 2004

Debris flow in the mountainous river gives rise to serious environmental and flooding problems. According to flood white book of Kangwon-do in 2002, over 30% of total of flooding victims are attributable to debris flow. But it has been neglected to build countermeasure to minimize victims due to lack of collected data and knowledge in field of the sediment yield of mountainous river. The study calculated hydraulic and hydrological fluctuation for rainfall condition using GIS data, after all we estimated the water surface of flood caused by bed fluctuation. These efforts will of for effective information for planning of river management.

• Journal of Korea Water Resources Association
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• v.35 no.4 s.129
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• pp.359-366
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• 2002

The damages from the natural disasters, especially from the floods, have been increasing. Therefore, it is imperative to establish a BMP to diminish the damages from the floods and to enhance the welfare of the nation. Developed countries have been generating and utilizing flood risk maps to raise the alertness of the residents, and thereby achieving efficient flood management. The major objectives of this research were to develop a prototype management system for flood risk map to forecast the boundaries oi the inundation and to plot them through the integration of geographic and hydrologic database. For more efficient system development, the user requirement analysis was made. The GIS database design was done based on the results from the research work of river information standardization. A GIS database for the study area was built by using topographic information to support the hydrologic modeling. The developed prototype include several modules; river information edition module, map plotting module, and hydrologic modeling support module. Each module enabled the user to edit graphic and attribute data, to analyze and to represent the modeling results visually. Subjects such as utilization of the system and suggestions for future development were discussed.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.1
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• pp.15-29
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• 2020

Recently, the incidence of flooding in Korea has decreased by the measures by central and local governments, however the scale of damage is increasing due to the improvement of living standard. One of the causes of such flood damage is natural causes such as rainfall exceeding the planned frequency of flood control under climate change. In addition, there are artificial causes such as encroachment of river spaces and management problems in upstream basins without consideration of downstream damage potential by regional development flood. In this study, in order to reduce the inundation damage caused by flooding of river, the situation at the time of inundation damage was reproduced by the detailed topographic data and 2D numerical model. Therefore, the effect of preparing various disaster prevention measures for the lowland was simulated in advance so that quantitative evaluation could be achieved. The target area is Taehwa river basin, where flooding was caused by the flooding of river waters caused by typhoon Chaba in October 2016. As a result of rainfall-discharge and two-dimensional analysis, the simulation results agree with the observed in terms of flood depth, flood arrival time and flooded area. This study examined the applicability of hydraulic analysis on river using two-dimensional inundation model, by applying detailed topographic data and it is expected to contribute to establish of disaster prevention measures.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.3
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• pp.141-152
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• 2017

This paper presents a technical method for flood estimation based on satellite rainfall and satellite rainfall correction method for watersheds lacking measurement data. The study area was the Sebou Watershed, Morocco. The Integrated Flood Analysis System(IFAS) and Grid-based Rainfall-Runoff Model(GRM) were applied to estimate watershed runoff. Daily rainfall from ground gauges and satellite-derived hourly data were used. In the runoff simulation using satellite rainfall data, the composites of the daily gauge rainfall and the hourly satellite data were applied. The Shuttle Radar Topographic Mission Digital Elevation Model(SRTM DEM) with a 90m spatial resolution and 1km resolution data from Global map land cover and United States Food and Agriculture Organization(US FAO) Harmonized World Soil Database(HWSD) were used. Underestimated satellite rainfall data were calibrated using ground gauge data. The simulation results using the revised satellite rainfall data were $5,878{\sim}7,434m^3/s$ and $6,140{\sim}7,437m^3/s$ based on the IFAS and GRM, respectively. The peak discharge during flooding of Sebou River Watershed in 2009~2010 was estimated to range from $5,800m^3/s$ to $7,500m^3/s$. The flood estimations from the two hydrologic models using satellite-derived rainfall data were similar. Therefore, the calibration method using satellite rainfall suggested in this study can be applied to estimate the flood discharge of watersheds lacking observational data.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.4 s.31
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• pp.21-26
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• 2004

Annually repeated flood damage is bringing about the rapid increasement of the loss of human lives and properly, and the enormous social cost for the restoration work is required. The annual amount of flood damage caused by the abnormal climate is reached about 1% of GDP, so more effective management of the flood control operation is needed to prevent the repetitive flood occurred same region. Also, the systematic planning and management or river improvement works are keenly required for the more effective execution of government working budget that expense to recover or to prevent the flood damage. The several organizations of government - Ministry of Construction & Transportation, Ministry of Government Administration and Home Affair, Ministry of Agriculture and Forestry, Ministry of Environment, Ministry of Science & Technology, Korea Meteorological Adminstration and so on - are promoting the flood prevention operations, but those promotion system makes it difficult to maintain the consistency of works. In this study, we try to develop the Web-GIS system prototype that will be able to effectively manage the nationwide river improvement works and to establish a framework that will be able to maintain the consistency of river improvement works. To achieve the study goals, we analysed current system of flood prevention operations, gathered related documents, had interviews with many government employees, and developed the Web-GIS system prototype.