• Journal of Korean Society of Forest Science
• /
• v.103 no.4
• /
• pp.537-546
• /
• 2014

The purpose of this study was to interpret ecological characteristics and to estimate successional trend for seven classified forest cover types (Quercus mongolica pure forest, Q. mongolica-Q. serrata forest, Mixed mesophytic forest, Abies koreana-Q. mongolica forest, Fraxinus mandshurica forest, Q. serrata forest, and Carpinus laxiflora forest) in the natural forest of Western Jirisan. Q. mongolica pure forest and A. koreana-Q. mongolica forest which were distributed in a high-altitude ridge had the lowest species diversity index. On the other hand, mixed mesophytic forest and F. mandshurica forest which were mainly distributed in the valley had higher index. Based on characteristics of species diversity and topographic conditions, successional trends for forest cover types were estimated as follows; 1) Q. mongolica pure forest and A. koreana-Q. mongolica forest would be changed toward Q. mongolica-A. koreana forest. 2) Q. mongolica-Q. serrata forest, distributed between ridge and mid-slope, would be changed toward Q. mongolica-C. laxiflora-C. cordata forest. 3) Q. serrata forest, distributed in mid-slope, would be changed toward Q. serrata-Q. mongolica-C. laxiflora forest. 4) Mixed mesophytic forest, F. mandshurica forest and C. laxiflora forest, distributed in valley, would maintain the current condition in terms of species composition.

• Journal of the Korean Geophysical Society
• /
• v.9 no.4
• /
• pp.321-331
• /
• 2006

Recently, runoff characteristics of urban area are changing because of the increase of impervious area by rapidly increasing of population and industrialization, urbanization. It needs to extract the accurate topologic and hydrologic parameters of watershed in order to manage water resource efficiently. Thus, this study developed more precise input data and more improved parameter estimating procedures using GIS(Geographic Information System) and GA(Genetic Algorithm). For these purposes, XP-SWMM (EXPert-Storm Water Management Model) was used to simulate the urban runoff. The model was applied to An-Yang stream basin that is a typical Korean urban stream basin with several tributaries. The rules for parameter estimation were composed and applied based on quantity parameters that are investigated through the sensitivity analysis. GA algorithm is composed of these rules and facts. The conditions of urban flows are simulated using the rainfall-runoff data of the study area. The data of area, slope, width of each subcatchment and length, slope of each stream reach were acquired from topographic maps, and imperviousness rate, land use types, infiltration capacities of each subcatchment from land use maps, soil maps using GIS. Also we gave the management scheme of urbanization runoff using XP-SWMM. The parameters are estimated by GA from sensitivity analysis which is performed to analyze the runoff parameters.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.5
• /
• pp.27-35
• /
• 2019

The purpose of this study is to analyze the displacement characteristics in slow-moving landslide area using digital elevation model and airborne LiDAR when unpredictable disaster such as slow-moving landslide occurred. We also aimed to provide basic data for establishing a rapid, reasonable and effective restoration plan. In this study, slow-moving landslide occurrence cracks were selected through the airborne LiDAR data, and the topographic changes and the scale of occurrence were quantitatively analyzed. As a result of the analysis, the study area showed horseshoe shape similar to the general form of slow-moving landslide occurrence in Korea, and the direction of movement was in the north direction. The total area of slow-moving landslide damage was estimated to about 2.5ha, length of landsldie scrap 327.3m, average width 19.3m, and average depth 8.6m. The slow-moving landslides did not occur on a large scale but occurred on the adjacent slope where roads were located, caused damage to retaining walls and roads. The field survey of slow-moving landslides was limited by accessibility and safety issues, but there was an advantage that accurate analysis was possible through the airborne LiDAR. However, because airborne LiDAR has costly disadvantages, it has proposed a technique to mount LiDAR on UAV for rapidity, long-term monitoring. In a slow-moving landslide damage area, information such as direction of movement of cracks and change of scale should be acquired continuously to be used in restoration planning and prevention of damage.

• Journal of Korean Society of Forest Science
• /
• v.100 no.4
• /
• pp.664-671
• /
• 2011

Random Walk Model can predict the sediment areas of debris flow but it must be extracted three parameters fitted topographical environment. This study developed the method to extract the optimal values of three parameters - Once flowing volume, Stopping slope and Gravity weight - for Random Walk Model. And the extracted parameters were validated by aerial photographs of the debris flowed area. To extract the optimal parameters was randomly performed, limiting the range values of three parameters and developing an accuracy decision method that is called the rate of concordance. The set of the optimal parameters was decided on highest the rate of concordance and a consistency. As a result, the optimal parameters in Bonghwa county were showed that the once flowing volume is $1.0m^3$, the stopping slope is $4.2^{\circ}$ and the gravity weight is 2 when the rate of concordance is -0.2. The validating result of the optimal parameters showed closely that the rate of concordance is average -0.2.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.49 no.3
• /
• pp.79-88
• /
• 2007

This paper suggests a hierarchial method to select the target sites for the nonpoint source pollution management considering factors which reflect the interrelationships of significant outflow characteristics of nonpoint source pollution at given sites. The factors consist of land slope, delivery distance to the outlet, effective rainfall, impervious area ratio and soil loss. The weight of each factor was calculated by an analytic hierarchy process(AHP) algorithm and the resulting influencing index was defined from the sum of the product of each factor and its computed weight value. The higher index reflect the proposed target sites for nonpoint source pollution management. The proposed method was applied to the Baran HP#6 watershed, located southwest from Suwon city. The Agricultural Nonpoint Pollution Source(AGNPS) model was also applied to identify sites contributing significantly to the nonpoint source pollution loads from the watershed. The spatial correlation between the two results for sites was analyzed using Moran's I values. The I values were $0.38{\sim}0.45$ for total nitrogen(T-N), and $0.15{\sim}0.22$ for total phosphorus(T-P), respectively. The results showed that two independent estimates for sites within the test water-shed were highly correlated, and that the proposed hierarchial method may be applied to select the target sites for nonpoint source pollution management.

• Journal of the Korean association of regional geographers
• /
• v.19 no.4
• /
• pp.737-746
• /
• 2013

This study was carried out to suggest plan of earth surface erosion by typifying landforms in Gwangeung Forest. Elements of landform were classifyed as hierachical system by scale. Scale for classification set a decision as four categories. We could classify landforms which level zero is 4 levels of elements, level one is 6, level two is twelve, level three is twenty seven. However, micro landforms of valley bottom which is hard to mapping made a categorization as upper valley, middle valley, artificial channel valley. Plan for soil erosion suggested yarding corridor, landform management for surroundings of slope and bridge using rock and gravel, road construction for forest management stable bedrock rather than soil layer, repose angles and piling up rocks for channel walls, and setting up buffer zone when forest thinning be carried out. The result of this research will be expected to provide information for forest management of mountainous areas by landform types.

• Journal of Korean Society of Forest Science
• /
• v.104 no.2
• /
• pp.300-308
• /
• 2015

Landscape planning system established in 2007. It is necessary that forest landscape management will be established based on the long-term and wide scope plan for forest management. This study suggested the considering factor while the establishing forest landscape plan for forest characteristics. Forest landscape type was consisted of 4 medium classification(geographical resources, waterscape, forest resources, cultural resources) and 12 small classification(geographical resources: panorama of ridge, ridge of curious rock peaks, waterscape: waterfall, valley, lake, forest resources: crown layer scenery, royal azaleas of main ridge, autumnal tints of ridge slope, flowers in herbaceous plants, inside of forest, forest trail scenery, cultural resources: facilities). This study suggested that consideration on 6 functions of forest in landscape zone planning and forest landscape management plan each classification (main ridge, sense of season, waterscape, rock resources).

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.17 no.1
• /
• pp.185-201
• /
• 2014

The Yong-neup of Mt. Daeam, which was designated as Korea's National Monument No.246 in 1973, is a high moor, and it has been managed with the designation as an ecosystem conservation area, Ramsar wetlands, and wetland conservation area. With the closing of the officially announced 5-year period for 'No-Trespassing' on the ecosystem conservation area starting August, 2010, it becomes necessary to arrange a systematic management and conservation scheme in consideration of the access & use of the visitors and Yong-neup's potential change into land consequent on making it open to the public. This study thinks that in order to preserve the Yong-neup, it's necessary to prepare the conservation plan for the program operation for exterminating exotic species, development of replacement wetlands and nurseries, access limit through zone categorization, establishment of environment-monitoring system, institutional management support, and establishment of managing facilities, etc., and to make scientific approaches, such as survey on wetland ecosystem, establishment of inventories, wetland monitoring, and drawing up of wetland ecology maps, etc. In addition, it is required that there should be adequate considerations of restoration of slope faces, drains, artificial embankment, water-collecting wells, roads for military operations, and wild-boar-stricken areas, etc., and should be continuous and systematic management of Yong-neup through the wise use of residents' participation-style maintenance, organization of a consultative body, introduction of CEPA programs, and introduction of visiting facilities and alternative transportation system, etc.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.82-84
• /
• 2003

Watershed boundaries and flow paths within the watershed are the most important factors required in watershed analysis. Most often the derivation of watershed boundaries and stream network and flow paths is based on topographical maps but spatial variation of flow direction is not clearly understandable using this method. Water resources projects currently use 1: 50, 000-scale ground survey or aerial photography-based topographical maps to derive watershed boundary and stream network. In basins, where these maps are not available or not accessible it creates a real barrier to watershed geo-spatial analysis. Such situations require the use of global datasets, like GTOPO30. Global data sets like ETOPO5, GTOPO30 are the only data sets, which can be used to derive basin boundaries and stream network and other terrain variations like slope aspects and flow direction and flow accumulation of the watershed in the absence of topographic maps. Approximately 1-km grid-based GTOPO 30 data sets can derive better outputs for larger basins, but they fail in flat areas like the Karkheh basin in Iran and the Amudarya in Uzbekistan. A new window in geo-spatial hydrology has opened after the launching of the space-borne satellite stereo pair of the Terra ASTER sensor. ASTER data sets are available at very low cost for most areas of the world and global coverage is expected within the next four years. The DEM generated from ASTER data has a reasonably good accuracy, which can be used effectively for hydrology application, even in small basins. This paper demonstrates the use of stereo pairs in the generation of ASTER DEMs, the application of ASTER DEM for watershed boundary delineation, sub-watershed delineation and explores the possibility of understanding the drainage flow paths in irrigation command areas. All the ASTER derived products were compared with GTOPO and 1:50,000-based topographic map products and this comparison showed that ASTER stereo pairs can derive very good data sets for all the basins with good spatial variation, which are equal in quality to 1:50,000 scale maps-based products.

• Journal of Korean Society of Forest Science
• /
• v.101 no.1
• /
• pp.1-6
• /
• 2012

To achieve the forest fire management goals such as early detection and quick suppression, fire resources should be allocated at high probability area where forest fires occur. The objective of this study was to develop and validate models to estimate spatially distributed probabilities of occurrence of forest fire. The models were builded by exploring relationships between fire ignition location and forest, terrain and anthropogenic factors using logistic regression. Distance to forest, cemetery, fire history, forest type, elevation, slope were chosen as the significant factors to the model. The model constructed had a good fit and classification accuracy of the model was 63%. This model and map can support the allocation optimization of forest fire resources and increase effectiveness in fire prevention and planning.