• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.36-36
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• 2023

Sedimentation is a natural process that occurs in all reservoirs. Sedimentation problem reduces the storage capacity of the reservoir and limits its ability to provide water for various uses, such as irrigation, hydropower generation, and flood control. Therefore, predicting reservoir sedimentation is important for ensuring the efficient operation and sedimentation management of a reservoir and . In this study, the HECRAS model was applied to predict longitudinal distribution of deposited sediment in the Pleikrong reservoir to 2050. Different scenarios was considered: (i) no climate change, (ii) climate change (under two emissions scenarios, RCP4.5 and RCP8.5), and (iii) climate change and land use change (followed land use planning of the watershed). The computation results with different scenarios were analyses and compared. The results show that the reservoir reduced storage volume's rate and sedimentation proceed toward to the dam in the case of climate change is faster than in the case of no climate change. Analyses also indicates that following the land used planning could also improve the long-term problem of the reservoir sedimentation. The outcomes of this study will be helpful for a sustainable plan of sediment management for the Pleikrong reservoir.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.3
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• pp.91-104
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• 2008

This study developed the WSM (weighted scenario method)-AHP method that can optimize the weighting value for multi-criteria to make GIS grid-based potential surface. The potential surface has been used to simulate urban expansion using distributed cellular automata model and to generate land-use planning as basic data. This study formulated the WSM-AHP method in mathematically and applied to test region, Suwon city, which located on south area from Seoul. WSM-AHP method generates potential map for each pair of weighting value for all criteria, which one criterion is weighted with high weighting value and the others use low weighting value, considering that the summation for all criteria weighting values should be "1". The potential change rate to the step of weighted scenario for weighting value of criteria is standardized like AHP intensity matrix in this study. From the standard potential change rate, WSM-AHP intensity matrix is completed, and then the optimal weighting value is calculated from the maximum eigenvector of the WSM-AHP matrix, according to the new WSM-AHP method developed in this study. The applied results of new method showed that the optimal weighting value from WSM-AHP is more resonable than the general AHP specialists' evaluation for weighting value. The another new finding of this study is to suggest the deterministic approach to optimize the weighting value for the distributed CA model, which is used to find new city area and to generate rational land-use planning.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2B
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• pp.215-224
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• 2008

The effect of streamflow considering future land use change and vegetation index information by climate change scenario was assessed using SLURP (Semi-distributed Land-Use Runoff Process) model. The model was calibrated and verified using 4 years (1999-2002) daily observed streamflow data for the upstream watershed ($260.4km^2$) of Gyeongan water level gauging station. By applying CA-Markov technique, the future land uses (2030, 2060, 2090) were predicted after test the comparison of 2004 Landsat land use and 2004 CA-Markov land use by 1996 and 2000 land use data. The future land use showed a tendency that the forest and paddy decreased while urban, grassland and bareground increased. The future vegetation indices (2030, 2060, 2090) were estimated by the equation of linear regression between monthly NDVI of NOAA AVHRR images and monthly mean temperature of 5 years (1998-2002). Using CCCma CGCM2 simulation result based on SRES A2 and B2 scenario (2030s, 2060s, 2090s) of IPCC and data were downscaled by Stochastic Spatio-Temporal Random Cascade Model (SST-RCM) technique, the model showed that the future runoff ratio was predicted from 13% to 34% while the runoff ratio of 1999-2002 was 59%. On the other hand, the impact on runoff ratio by land use change showed about 0.1% to 1% increase.

• Land and Housing Review
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• v.3 no.2
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• pp.111-116
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• 2012

The primary purposes of this study are to identify the characteristics of land development in urban area through GIS and remote sensing techniques and to provide useful implications for urban spatial policy. To perform these tasks, Daegu metropolitan city and its vicinities were selected as a study area, and remote sensing data and attributed data were collected, organized and analyzed. This study focuses on the following three steps. First, it identifies the characteristics of land development in urban areas by utilizing multi-temporal satellite image data (Landsat TM, 1980, 1985, 1990, 1995, 2000 and 2005). Second, it tries to find an answer on a critical question concerning land use conversion, i.e., which land use leads expansion of urban area? Third, it derives implications for urban spatial policies based on these findings. The characteristics of the urban extents tell us that the main land use converted into urban use from non-urban uses is green areas. The public sector, central and local governments, leads the land use conversions of suburban lands as exclusive legal body to issue permission of land use change. Based on these findings, this study concludes that the more systematic and technically advanced management tools should be utilized for more effective spatial management for urban growth.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.2
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• pp.36-46
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• 2007

The primary purpose of this study is to identify the characteristics of land use change at the urban fringe. For this purpose, the Daegu Metropolitan City is selected as a study area. Land use changes between 1990 and 2000 in fringe areas are identified by processing Landsat TM5 imageries. The main findings are follows: First, land development has been driven by residential development, especially large-scale residential development encouraged by the two-million housing construction plan. Second, the type and size of the land use conversion are not identical across the study area. For example, the main land use type of the newly developed area of Buk-gu is residential use while that of Suseong-gu is public use. Third, most of residential development type is a high-density development which is quite different from American type of low-density development.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.7
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• pp.23-32
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• 2004

A spatial simulation model for rural and urban sprawl phenomena was developed with GIS and cellular automata techniques. The model finds out built-up areas invading toward rural areas required for development of existing urban area. Probability of land use change for optimizing the development area was determined using a land suitability analysis method interfaced with GIS methods, based on several criteria in terms of geographic and accessibility factors such as slope of land and distance from city center. Weighting values of the criteria were quantified by an analytic hierarchy process method. For model applicability test, the parameters of criteria were calibrated based on the changes in time series land use data of the test city for 1986, 1996, and 2000, which were classified by remote sensing techniques. Simulated and observed areas in land use maps for city shape of 1996 showed good similarities with each other through a morphology verification method. The model enabled us to evaluate the spatial expansion phenomena of cities considering boundary conditions, and also to simulate land use planning for rural areas in urban fringe.

• Journal of the Korean Geographical Society
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• v.40 no.2 s.107
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• pp.221-241
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• 2005

Land Use and Land Cover Changes (LUCC) occur over a wide range of space and time scales, and involve complex natural, socio-economic, and institutional processes. Therefore, modelling and predicting LUCC demands an understanding of how various measured properties behave when considered at different scales. Understanding spatial and temporal variability of driving forces and constraints on LUCC is central to understanding the scaling issues. This paper aims to 1) assess the heterogeneity of land cover change processes over the landscape in northern Ghana, where intensification of agricultural activities has been the dominant land cover change process during the past 15 years, 2) characterise dominant land cover change mechanisms for various spatial scales, and 3) identify the optimal spatial scale for LUCC modelling in a savanna landscape. A multivariate statistical method was first applied to identify land cover change intensity (LCCI), using four time-sequenced NDVI images derived from LANDSAT scenes. Three proxy land use change predictors: distance from roads, distance from surface water bodies, and a terrain characterisation index, were regressed against the LCCI using a multi-scale hierarchical adaptive model to identify scale dependency and spatial heterogeneity of LUCC processes. High spatial associations between the LCCI and land use change predictors were mostly limited to moving windows smaller than 10$\times$10km. With increasing window size, LUCC processes within the window tend to be too diverse to establish clear trends, because changes in one part of the window are compensated elsewhere. This results in a reduced correlation between LCCI and land use change predictors at a coarser spatial extent. The spatial coverage of 5-l0km is incidentally equivalent to a village or community area in the study region. In order to reduce spatial variability of land use change processes for regional or national level LUCC modelling, we suggest that the village level is the optimal spatial investigation unit in this savanna landscape.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.3
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• pp.75-88
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• 2016

In this study, we used the CLUE-s model to predict the future land-use change based on the urban growth scenario in South Korea. The land-use maps of six classes (water, urban, rice paddy, upland crop, forest, and grass) for the year 2008 were obtained from the Ministry of Environment (MOE), and the land-use data for 5-year intervals between 1980 and 2010 were obtained from the Water Resources Management Information System (WAMIS), South Korea. For predicting the future land-use change, the MOE environmental conservation value assessment map (ECVAM) was considered for identifying the development-restricted areas, and various driving factors as location characteristics were prepared for the model. The predicted results were verified by comparing them with the land-use statistics of urban areas in each province for the year 2008. The prediction error rates were 9.47% in Gyeonggi, 9.96% in Gangwon, 10.63% in Chungbuk, 7.53% in Chungnam, 9.48% in Jeonbuk, 6.92% in Jeonnam, 2.50% in Gyeongbuk, and 8.09% in Gyeongnam. The sources of error might come from the gaps between the development of political decisions in reality with spatio-temporal variation and the mathematical model for urban growth rate in CLUE-s model for future scenarios. Based on the land-use scenario in 2008, the land-use predictions for the year 2100 showed that the urban area increased by 28.24%, and the rice paddy, upland crop, and forest areas decreased by 8.27, 6.72, and 1.66%, respectively, in South Korea.

• Spatial Information Research
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• v.10 no.1
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• pp.153-164
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• 2002

This used a new method to capture the neighbouring relationship among parcels. To define the neighbouring relationship, all the surrounding parcels in the study area can be identified as neighbours of the current parcel as long as they touch each other even at a point. To examine neighbouring parcels on all polygons of the study area, this study used ArcViews avenue programming which visited each polygon in turn and produced an outfile containing the parcel record ID and the contents of each of the adjacent parcels. The second thing is to translate the record IDs of neighbouring parcels into land use. For this, this study used the Lookup function in Excel to obtain neighbouring land use. To deal with how to calculate the ratio of each land use to neighbouring land uses, this study used Visual Basic. finally, this study considered a term of neighbour land use as the ratio of the number of urban use adjacent parcels to the total number of adjacent parcels. This study shows that GIS and spatial analysis can be applied to land use change in the urban fringe area at a very detailed level using municipal parcel data which occupies about 80% of administrative affairs, especially at the local government level in Korea. The results of analysis can be useful for local government to understand its situation and to manage land use efficiently in the urban fringe. The methodology developed in this study is especially useful for an empirical approach.

• Journal of the Korean Geographical Society
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• v.40 no.6 s.111
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• pp.694-715
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• 2005

I examine in this paper the change of land use and the development of desertification in Horqin desert, east Inner Mongolia, China. The change of land use in this area can be summarized as the increase of agricultural field and intensive livestock farming. The agriculture and livestock farming in semi-arid area such as Horqin desert raised the problem in the management and use of water and vegetation. This problem led to desertification. The types of development of desertification in this area could be classified as follows: the mobile sand dune extension, the riverside shifting sand flat extension, the shifting sand speck extension around settlements, and the shifting sand speck extension in agricultural Held and grassland. There have been political or social movements such as the Great Leap Forward, the Cultural Revolution and the Reform and Open Policy in the background of land use change and desertification. Specially, the Great Leap Forward and the Cultural Revolution played an important role in the land use change and desertification in this area. Since 1990s, there has been some kind of policy in the control of desertification. However, it is necessary for the controling desertification of this area to consider the globalization and marketization, the survival and profit of peasants and livestock farmers, and the disturbrd and fixed population and land use structure in this area since 1949.