• Spatial Information Research
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• v.6 no.1
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• pp.77-90
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• 1998

The complex interactions of climate, topography, geology, biota and hwnan activities result in the land cover patterns, which are impacted by natural disturbances such as fire, earthquake and flood. Natural disturbances disrupt ecosystem communities and change the physical environment, thereby generating a new landscape. Community ecologists believe that disturbance is critical in determining how diverse ecological systems function. Fires were once a major agent of disturbance in the North American tall grass prairies, African savannas, and Australian bush. The major focus of this research was to develop stochastic model of spatial process of disturbance or spatial events and simulate the process based on the developed model and it was applied to the fire arrival process in the Great Victoria Desert of Australia, where wildfires generate a mosaic of patches of habitat at various stages of post-fire succession. For this research, Landsat Multi-Spectral Scanner(MSS) data covering the period from 1972 to 1994 were utilized. Fire arrival process is characterized as a spatial point pattern irregularly distributed within a region of space. Here, nonhomogeneous planar Poisson process is proposed as a model for the fire arrival process and rejection sampling thinning the homogeneous Poisson process is used for its simulation.

• Atmosphere
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• v.20 no.3
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• pp.273-286
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• 2010

The northeast part of China(hereafter Manchuria) is one of Asian dust source regions along with Gobi, Inner Mongolia and Loess Plateau. In this study, a geographical survey over the area was carried out to determine its soil characteristics in June 2009. It revealed that some parts of the area, especially near Keerchin desert, consist of alkali clay soil mixed up with sand. Manchuria, where is a vast cornfield, can be a potential source region of Asian dust from fall to following spring after harvesting. The frequency of Asian dust over the region from 1996 to 2009 was examined using 3-hourly GTS SYNOP data and it showed that the occurrence of Asian dust over the region is high in the springtime. It was also revealed that snow cover is the key parameter affecting on the frequency through the analysis of NCEP reanalysis data. To scrutinize the path and structure of Asian dust from Manchuria, the event on 3~4 April 2008 and 25 January 2010 were intensively investigated with regard to features of synoptic weather patterns, satellite imagery, airstream, naked eye-observations, concentrations of PM10, 2.5 and 1.0. For this case, the Asian dust from the area reached to Korea less than a day. However, the duration time of the dust in Korea was short (< 7 hours). The average of hourly PM10 reached up to $340{\mu}g/m^{3}$ at Baengnyeondo during the period. The high PM2.5 and PM1.0 concentrations were also observed at several sites in Korea, indicating that air pollutants could be transported along with the dust.

• Geomechanics and Engineering
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• v.24 no.5
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• pp.407-418
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• 2021

Due to the complexity of the causes of the sliding mass instabilities, landslide susceptibility and hazard evaluation are difficult, but they can be more carefully considered and regionally evaluated by using new programming technologies to minimize the hazard. This study aims to evaluate the landslide hazard zonation in the Tabriz region, Iran. A fuzzy logic-based multi-criteria decision-making method was proposed for susceptibility analysis and preparing the hazard zonation maps implemented in MATLAB programming language and Geographic Information System (GIS) environment. In this study, five main factors have been identified as triggering including climate (i.e., precipitation, temperature), geomorphology (i.e., slope gradient, slope aspect, land cover), tectonic and seismic parameters (i.e., tectonic lineament congestion, distribution of earthquakes, the unsafe radius of main faults, seismicity), geological and hydrological conditions (i.e., drainage patterns, hydraulic gradient, groundwater table depth, weathered geo-materials), and human activities (i.e., distance to roads, distance to the municipal areas) in the study area. The results of analyses are presented as a landslide hazard map which is classified into 5 different sensitive categories (i.e., insignificant to very high potential). Then, landslide susceptibility maps were prepared for the Tabriz region, which is categorized in a high-sensitive area located in the northern parts of the area. Based on these maps, the Bozgoosh-Sahand mountainous belt, Misho-Miro Mountains and western highlands of Jolfa have been delineated as risk-able zones.

• Journal of Korean Society of Forest Science
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• v.33 no.1
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• pp.1-32
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• 1977

This study has been made to find out more effective way of vegetation establishment on severely denuded forest land from the viewpoint of soil moisture regimes. Various environmental factors were measured to estimate soil moisture conditions of different sites. Soil moisture influence on growth of over vegetations, water requirement and drought resistance were analyzed. The efficiency of water use was also reckoned at different fertility levels and different soil moisture conditions. This research is composed of field experiment and green house experiment. Field experiment includes height growth, survival and coverage analysis of cover vegetations (Robinia pseudoacacia L., Lespedeza bicolor Turcz, Arundinella hirta Tanaka var. ciliare Koidzumi.) with 4 fertility level treatments on 3 slopes (Steep: $37^{\circ}$, Moderate: $25^{\circ}$, Gentle; $17^{\circ}$) during dry season (1 April-30 June) and wet season (1 July-10 September). At the same time temperature, relative humidity and precipitation were measured to understand the environmental changes. Soil moisture conditions were measured with soil moisture meter with 24 soil cells. Green house experiment comprised height, fresh weight and dry weight measurements of cover vegetations with 4 fertility levels and 3 moisture conditions for 70 days. The results extracted from experiments are as follews. 1. Cover vegtations have 3 patterns of water requirement at the early stage of growth. a) Robinia type has high water requirement and weaker drought resistance. b) Lespedeza type has low water requirement and stronger drought resistance. c) Arundinella type has moderate water requirement and weaker drought resistance. 2. The vegetations have different optimum fertility levels in different soil moisture supply condition. a) Robinia needs a low fertility level in dry condition and a high level in wet condition. b) Lespedeza needs only low fertility level in all conditions. c) Arundinella needs a low fertility level in dry condition and a high level in wet condition. 3. The efficiency of water use (Water/1g dry weight) by fertility levels is different from one another. Robinia and Arundinella have a good efficiency at low fertility level in dry condition and at high fertility level in wet condition. Lespedeza has a good efficiency at low fertility level in all conditions. 4. $P_2O_5$ requirement of Robinia and Lespedeza is high, but that of Arundinella is low. Soil moisture condition has a great influence on $P_2O_5$ absorption in dendued forest land. Once Vegetations are established on suitable sites with optimum fertitity level according to different moisture condition, even the small amount of soil water in denuded land can he used with high efficiency and the effect of fertility treatment can be maximized.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.3
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• pp.13-26
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• 2015

Many urban areas in Korea suffer from repeated flood damage during intensive rainfall due to an increase in impervious areas caused by rapid urbanization and deteriorating sewage systems. A centralized stormwater management system has caused severe flood damage in an area that has proven unable to accommodate recent climate change and a rise in precipitation. Most flooding prevention projects that have been recently implemented focus on increasing drainage system capacity by expanding the size of sewer pipes and adding pumping stations in downstream areas. However, such measures fail to provide sustainable solutions since they cannot solve fundamental problems to reduce surface runoff caused by urbanization across the watershed. A decentralized stormwater management system is needed that can minimize surface runoff and maximize localized retention capacity, while maintaining the existing drainage systems. This study proposes a stormwater management corridor for the flood-prone watershed in the city of Dongducheon. The corridor would connect the upstream, midstream, and downstream zones using various methods for reducing stormwater runoff. The research analyzed surface runoff patterns generated across the watershed using the Modified Rational Method considering the natural topography, land cover, and soil characteristics of each sub-watershed, as well as the urban fabric and land use. The expected effects of the design were verified by the retainable volume of stormwater runoff as based on the design application. The results suggest that an open space network serve as an urban green infrastructure, potentially expanding the functional and scenic values of the landscape. This method is more sustainable and effective than an engineering-based one, and can be applied to sustainable planning and management in flood-prone urban areas.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.543-553
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• 2013

In Korea, there have been many studies and progresses on various types of pilot scale or commercialized field scale Best Management Practices(BMP) during the last 10 years. Runoff characteristics of diffuse pollutants from different land uses are well identified and documented. However, for the coastal area connected directly with shoreline, runoff patterns and management schemes of non-point pollution were not fully studied. Recently, coastal area is emerging as a new development axis especially in west coast side of Korea such as Incheon city and Chungnam province, thus urbanized area rapidly increased but there are no buffer zones and BMP facilities to aim at preventing direct discharge of the first flush into coastal sea and beaches. In this study, parking area in Deacheon harbor, Boryeong City in Chungnam Province was selected and rainfall runoff was monitored for two year period in order to examine run-off features from which proper type of BMP suitable for coastal area is proposed. Coastal area usually has a low ground water level and consists of plain land, so that large scale BMP such as storm water retention pond and wetland requiring great excavation works is not best management plan. In addition, monitoring study shows that storm water from the paved parking area has a high salinity compared with those in storm water from the inland. High salinity is detrimental for the vegetation. Therefore, BMP employing least vegetative cover and also in terms of maintenance is a good option such as infiltration trench and porous pavement.

• Journal of Cadastre & Land InformatiX
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• v.47 no.2
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• pp.19-37
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• 2017

Visible Infrared Imaging Radiometer Suite Day-Night Band (VIIRS-DNB) data provides a much higher capability for observing and quantifying nighttime light (NTL) brightness in comparison with Defense Meteorological Satellite-Operational Linescan System (DMSP-OLS) data. In South Korea, there is little research on the detection of NTL brightness change using VIIRS-DNB data. This study analyzed the spatial distribution and change of NTL brightness between 2013 and 2016 using VIIRS-DNB data, and detected its spatial relation with possible influencing factors using regression models. The intra-year seasonality of NTL brightness in 2016 was also studied by analyzing the deviation and change clusters, as well as the influencing factors. Results are as follows: 1) The higher value of NTL brightness in 2013 and 2016 is concentrated in Seoul and its surrounding cities, which positively correlated with population density and residential areas, economic land use, and other factors; 2) There is a decreasing trend of NTL brightness from 2013 to 2016, which is obvious in Seoul, with the change of population density and area of industrial buildings as the main influencing factors; 3) Areas in Seoul, and some surrounding areas have high deviation of the intra-year NTL brightness, and 71% of the total areas have their highest NTL brightness in January, February, October, November and December; and 4) Change of NTL brightness between summer and winter demonstrated a significantly positive relation with snow cover area change, and a slightly and significantly negative relation with albedo change.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.502-509
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• 2011

It is important to determine optimum soil covering depths for tree survival and growth because soil covering depths for establishing tree planting bases in coastal reclaimed lands are related to the costs for soil collection, transportation and land reclamation. The objectives of this study were carried out to determine optimum soil covering depths for the normal growth of planted trees in a coastal reclaimed land. The study sites were located in Asan National Industrial Complex in Pyeongtaek City, Gyeonggi-do. Four tree species (Pinus thunbergii, Chamaecyparis pisifera, Zelkova serrata, Quercus acutissima) with one hundred eighty trees of each species were planted in various depths of soil covering (no soil covering, 0.5 m, 1.5 m, 2.0 m soil covering treatments) on April 1998, and the tree growth patterns were measured on September 2000. The change of soil properties, tree mortality rate, root collar diameter and height growth were measured from each soil covering depth treatment on September 2000. Soil pH, EC, exchangeable cations ($K^+$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$), anion $Cl^-$, and base saturation increased with decreased soil covering depths. The mortality rates of tree species showed decreased with increased soil covering depths. The height growth of tree species increased with increased soil covering depths. Height growth of Pinus thunbergii was significantly different between the soil covering depth below 0.5m and other three covering depths, while the growth of other species (C. pisifera, Z. serrata, Q. acutissima) was significantly higher in soil covering depths below 1.5 m than in other soil covering depth treatments. The root collar diameter growth of all tree species showed increasing trends with increased soil covering depths. It is recommended to cover the soil depths above 1.5 m to decrease mortality and to stimulate the tree growth of C. pisifera, Z. serrata and Q. acutissima, while P. thunbergii which is a salt tolerate species could be planted in the 1.0 m soil covering depth.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.2
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• pp.145-156
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• 2005

An artificial disturbance like forest fragmentation has affected the sustainability of forest ecosystem. Therefore, in order to manage the forest ecosystem efficiently needed to analyze quantity and quality (structural pattern) of forest simultaneously. This study analyzed the structural patterns of forest landscape to provide a basic data for evaluation and management of forest ecosystem in Nakdong River Basin during 10 years from 1980s to 1990s using landscape indices and GIS methods. Forest distribution maps and 6 landscape indices(LPI, PD, ED, MSI, CPLAND, IJI) for the analysis were reconstructed from land-cover maps constructed by Ministry of Environment and pearson correlation analysis. According to the structural analysis of forest landscape using landscape indices, the forest fragmentation of watersheds along the main stream of the Nakdong river was more severe than any other watersheds. Futhermore, the Nakong-sangju and Nakdong-miryang watersheds had unstable forest structures as well as least amount of forest quantity. Thus, these watersheds need significant amount of forest through a new forest management policy considering local environmental conditions. The connectivity between forests in local regions should be considered as well.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.4
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• pp.384-398
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• 2015

In this paper, the high-resolution Weather Research and Forecasting/Noah-MultiParameterization (WRF/Noah-MP) modeling system is configured for the Cheongmicheon Farmland site in Korea (CFK), and its performance in land and atmospheric simulation is evaluated using the observed data at CFK during the 2014 special observation period (21 August-10 September). In order to explore the usefulness of turning on Noah-MP dynamic vegetation in midterm simulations of surface and atmospheric variables, two numerical experiments are conducted without dynamic vegetation and with dynamic vegetation (referred to as CTL and DVG experiments, respectively). The main results are as following. 1) CTL showed a tendency of overestimating daytime net shortwave radiation, thereby surface heat fluxes and Bowen ratio. The CTL experiment showed reasonable magnitudes and timing of air temperature at 2 m and 10 m; especially the small error in simulating minimum air temperature showed high potential for predicting frost and leaf wetness duration. The CTL experiment overestimated 10-m wind and precipitation, but the beginning and ending time of precipitation were well captured. 2) When the dynamic vegetation was turned on, the WRF/Noah-MP system showed more realistic values of leaf area index (LAI), net shortwave radiation, surface heat fluxes, Bowen ratio, air temperature, wind and precipitation. The DVG experiment, where LAI is a prognostic variable, produced larger LAI than CTL, and the larger LAI showed better agreement with the observed. The simulated Bowen ratio got closer to the observed ratio, indicating reasonable surface energy partition. The DVG experiment showed patterns similar to CTL, with differences for maximum air temperature. Both experiments showed faster rising of 10-m air temperature during the morning growth hours, presumably due to the rapid growth of daytime mixed layers in the Yonsei University (YSU) boundary layer scheme. The DVG experiment decreased errors in simulating 10-m wind and precipitation. 3) As horizontal resolution increases, the models did not show practical improvement in simulation performance for surface fluxes, air temperature, wind and precipitation, and required three-dimensional observation for more agricultural land spots as well as consistency in model topography and land cover data.