• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.3
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• pp.12-26
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• 2017

The objective of this study was to develop a runoff analysis system of the Nakdong River watershed using the GRM (Grid-based Rainfall-runoff Model), a physically-based distributed rainfall-runoff model, and to assess the system run time performance according to Microsoft Azure VM (Virtual Machine) settings. Nakdong River watershed was divided into 20 sub-watersheds, and GRM model was constructed for each subwatershed. Runoff analysis of each watershed was calculated in separated CPU process that maintained the upstream and downstream topology. MoLIT (Ministry of Land, Infrastructure and Transport) real-time radar rainfall and dam discharge data were applied to the analysis. Runoff analysis system was run in Azure environment, and simulation results were displayed through web page. Based on this study, the Nakdong River real-time runoff analysis system, which consisted of a real-time data server, calculation node (Azure), and user PC, could be developed. The system performance was more dependent on the CPU than RAM. Disk I/O and calculation bottlenecks could be resolved by distributing disk I/O and calculation processes, respectively, and simulation runtime could thereby be decreased. The study results could be referenced to construct a large watershed runoff analysis system using a distributed model with high resolution spatial and hydrological data.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.281-284
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• 2002

Geographic Information System (GIS) has advantage of analyzing spatial distributed data and handling spatial data for hydrologic analysis. Hydrologic Engineering Center's Hydrologic Modeling System(HEC-HMS) with HEC-GeoHMS was used to analyze flood runoff at agricultural small watershed. HEC-GeoHMS, which is an ArcView GIS extension designed to process geospatial data for HEC-HMS, is a useful tool for storing, managing, analyzing, and displaying spatially distributed data. Hydroligical component including peak discharge, time to peak, direct runoff, baseflow for Balhan study watershed, which is located in Whasung city, Kyunggi province, having an area of $29.79km^2$, were calculated using the HEC-HMS model with HEC-GeoHMS.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.314-318
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• 2001

The analysis of the spatial extent of flood inundation is important for flood mitigation. Geographic Information System (GIS) has advantage of analyzing spatial distributed data. Hydrologic Engineering Center's River Analsysis System(HEC-RAS) with HEC-GeoRAS was used to analyze flood inundation. HEC-GeoRAS, which is an ArcView GIS extension designed to process geospatial data for HEC-RAS, is a useful tool for storing, managing, analyzing, and displaying spatially distributed data. Rational formula and 24-hr duration probability precipitation data of Suwon meteorological station were used to estimate the flood runoff. And water profiles were calculated using the HEC-RAS model with HEC-GeoRAS. The flooded region is 8.24ha when 50-yr probability precipitation was applied and 8.8ha when 100-yr was applied to Bahlan study watershed which is located in Whasung county, Kyunggi province, having an area of $29.79km^{2}$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2713-2719
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• 2012

According to increasing of various location-based services, distributed data stream processing techniques have been widely studied to provide high scalability and availability. In previous researches, in order to balance the load of distributed nodes, the geographic characteristics of spatial data stream are not considered. For this reason, distributed operations for adjacent spatial regions increases the overall system load. We propose a operation allocation scheme considering the characteristics of spatial operations to effectively processing spatial data stream in distributed computing environments. The proposed method presents the efficient share maximizing approach that preferentially distributes spatial operations sharing the common query regions to the same node in order to separate the adjacent spatial operations on overlapped regions.

• Journal of Korean Society of Rural Planning
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• v.8 no.3 s.17
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• pp.41-48
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• 2002

Spatially distributed characteristic of longevity regions analysed using GIS tools. Fundamental factors for long life are categorized into natural conditions and artificial conditions. Degree of longevity is defined and used as a key parameter in analyzing longevity region. It is visually shown that aging areas are moving with time and variances of social and economic status. It is concluded that the degree of longevity is increased with improving living quality because of improvement of economic activities and living environment. However, longevity regions of recent times have slightly reversed tendency against urban areas in the manner of moving toward areas where social and economical activities are relatively weaker.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.2
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• pp.9-14
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• 1999

This paper describes an algorithm for the correction of major radiometric errors shown in MEIS (Multi-spectral Earth Imaging System) images on board KITSAT-3. MEIS images contain various radiometric errors as also shown in the images obtained from other remote sensing sensors. This paper introduces the two major radiometric error sources shown in MEIS images and the corresponding correction algorithm. The proposed algorithm was integrated to an operational preprocessing software and validated by applying the algorithm to several tens of MEIS images. This algorithm will therefore applied operationally to raw MEIS images before they are distributed to users.

• Journal of Korea Water Resources Association
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• v.45 no.6
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• pp.597-606
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• 2012

With the availability of multi-scale hydrologic data in public domain depending on DEM size, there is a need for a modeling framework that is capable of using these data to simulate hydrologic processes at multiple scales for different topographic and climate conditions for distributed hydrologic model. To address this need, an object-oriented approach, called Geographic and Hydrologic Information System Modeling Objects (GHISMO), is developed. Main hydrologic approaches in GHISMO are storage-release for direct runoff and SCS curve number method for infiltration part. This paper presents conceptual and structural framework of storage-release concept including its application to two watersheds will be presented.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.2
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• pp.144-159
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• 2006

Hydrological models are tools intended to realistically represent the basin's complex system in which hydrological characteristics result from a number of physical, vegetative, climatic, and anthropomorphic factors. Spatially distributed hydrological models were first developed in the 1960s, Remote sensing(RS) data and Geographical Information System(GIS) play a rapidly increasing role in the field of hydrology and water resources development. Although very few remotely sensed data can applied in hydrology, such information is of great. One of the greatest advantage of using RS data for hydrological modeling and monitoring is its ability to generate information in spatial and temporal domain, which is very crucial for successful model analysis, prediction and validation. In this paper, SLURP model is selected as semi-distributed hydrological model and MODIS Leaf Area Index(LAI), Normalized Difference Vegetation Index(NDVI) as Remote sensing input data to hydrological modeling of Kyung An-chen basin. The outlet of the Kyung An stage site was simulated, We evaluated two RS data, based on ability of SLURP model to simulate daily streamflows, and How the two RS data influence the sensitivity of simulated Evapotranspiration.

• Journal of the Korean Association of Geographic Information Studies
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• v.1 no.1
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• pp.70-85
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• 1998

This study intends to identify the effects of user attitude, user education & training on the information systems implementation performance. In order to obtain data, survey questionnaires were distributed to the users of 'D' company, the major findings can be summarized as follows. First, it's suggested from the analyses that user attitude and user education & training independently have statistically significant effects on information systems implementation performance. Second, it's revealed that even though the interaction effects by both user attitude and user education & training have positive effects on the level of usage, but have no statistically significant effects on satisfaction level. Based on these results, it's recommended to convert user attitude favorably toward user environment and to increase the level of user education & training, in order to promote information systems implementation performance. Especially, differentiated user education & training are highly recommended.

• Journal of Korean Society of Rural Planning
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• v.18 no.1
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• pp.9-15
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• 2012

This study used GIS method for the characteristic analysis of farmstead location in study area. The present study surveyed the coordinates of location for 76 livestock farmsteads with big size in rural areas within city of Cheonan. Based on the surveyed data, this study analyzed the spatial characteristics of location for the farmsteads by using both new evaluation criteria and their corresponding GIS (geographic information system) layers developed in this research. The criteria consist of six factors, which are 2 geographic factors for slope(SLO) and aspect(ASP) of earth surface, 3 accessability factors for distance from water area(DWA), road(DRO), and built-up area(DBA), including type of landuse(TLA). In the analysis results of six criteria using the grid funcations of GIS, the highest distributed ratios of the farmsteads per criterion were found at the lower slope area less then 2% in SLO, the area with south and south-east direction in ASP, the area with distance between 500m and 1,000m in both DWA and DRO, the area within 500m in DWA, and the paddy and upland area in TLA. As new finding of this study, these analysis results seemed that the farmsteads have been located at the better places with the priority to build and manage conveniently and economically.