• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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• pp.94-106
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• 2008

As populations inhabiting in natural ecosystem are fragmented by artificial barriers and habitats are destructed by development, extinction possibility of species is getting higher. It is necessary to design and to manage conservation areas and corridors considering animals' movement and migration for sustainable species diversity in present circumstances. 'Least-cost modeling' is one commonly employed approach in which dispersal costs are assigned to distinct habitat types and the last-costly dispersal paths among habitat patches are calculated using a geographical information system (GIS). This study aims to design ecological corridor using least-cost path method and to apply it to a regional ecological network considering movability of medium-large size mammals. This study was carried out over the metropolitan area, which has been deforested by rapid urbanization. Nevertheless there is connected with Gangwon province, Baekdudaegan mountain range and DMZ, considered where many forest species can migrate to this region. This study employs such an approach to develop least-cost path models for medium-large size mammals, have inhabited for this entire region. Considering those species, two forest areas as a source of species supply and forest areas more than 1,000ha are selected as focal forest areas. Movement and migration paths from species supply sources to focal forest areas are calculated by applying landscape permeability theory using land cover map, road density map and land slope map. Results showed least-cost paths from species supply sources to focal forest areas on two species. Wildcat and roe deer are different in some least-cost paths caused by their landscape permeability but paths show generally same specifics. The result of considering regional distribution of expected movement and migration paths to regional ecological network, low altitude mountains of western metropolitan area are evaluated important area for species connectivity. In national or regional levels ecological connectivity is essential to promote species diversity and to preserve integrated ecosystem. This study concludes that developing least-cost models from similar empirical data could significantly improve the utility of these tools.

• Journal of Environmental Impact Assessment
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• v.21 no.3
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• pp.391-407
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• 2012

The loss of connectivity and fragmentation of forest landscapes are seriously hindering dispersal of many forest-dwelling species, which may be critical for their viability and conservation by decreasing habitat area and increasing distance among habitats. For understanding their environmental impacts, numerous spatial models exist to measure landscape connectivity. However, general relationships between functional connectivity and landscape structure are lacking, there is a need to develop landscape metrics that more accurately measure landscape connectivity in whole landscape and individual patches. We reviewed functional and structural definition of landscape connectivity, explained their mathematical connotations, and applied representative 13 indices in 3 districts of Seoul having fragmented forest patches with tits, the threshold distance was applied 500m by considering the dispersal of tits. Results of correlation and principal component analysis showed that connectivity indices could be divided by measurement methods whether they contain the area attribute with distance or not. Betweenness centrality(BC), a representative index measuring distance and distribution among patches, appreciated highly stepping stone forest patches, and difference of probability of connectivity(dPC), an index measuring including area information, estimated integrated connectivity of patches. Therefore, for evaluating landscape connectivity, it is need to consider not only general information of a region and species' characteristics but also various measuring methods of landscape connectivity.

• Journal of the Korean GEO-environmental Society
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• v.4 no.3
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• pp.5-17
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• 2003

Using Rowe cell for vertical and lateral consolidate test, we concerned characteristics of vertical and lateral consolidation, and permeability on the remolded Decompoed Mudstone Soil in Phoang, and then, compared it with Oedometer test results. Indirect coefficients of permeability were calculated by the results of the coefficient of consolidation that were derived from 9 different kinds of methods. The values of indirect coefficients of permeability derived from ${\sqrt{t}}$ method and hyperbolic method were similar to the results of direct coefficients of permeability with respect to vertical drainage, but, in the case of lateral drainage, for all kinds of methods, the values of indirect coefficients of permeability showed overestimated ones. With vertical and lateral direct coefficient of permeability, by investigating the anisotropic effect with respect to permeability on Decomposed mudstone soil, we obtained average value, 13, with respect to anisotropic characteristics for all kinds of consolidation loadings.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.6
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• pp.77-83
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• 2001

The purpose of this study is to provide the fundamental material and information for the plant maintenance after rooftop planting through physiochemical characteristics. The characteristics of artificial soils after rooftop planting from 1993 to 1999 was investigated. Fourteen investigation areas were selected from 4 cities(2 areas selected by each year). The analysis of the circumstances of the areas, the physical characteristics, and the chemical characteristics of the soil were conducted. The artificial soil pH ranged 5.26∼7.40 showing that after construction the soil pH tended to decrease. The soil bulk density of the site was lowest in 1999, 0.15g/㎤, and used to increase toward 1993. We found the fact that the soil bulk density increased gradually after rooftop application . The coefficients of permeability of the soils range from 0.016 to 0.052 cm/sec, which seemed to be in good permeability level. The artificial soils had relatively high water moisture capacity of 62.69∼71.36%. The soil organic matter content of the artificial soils ranged from 0.43 to 1.34%. The exchangeable caution concentration in the artificial soil ranged, Na, 2.36∼4.71mg·{TEX}$kg^{-1}${/TEX}, Mg 0.88∼2.84mg·{TEX}$kg^{-1}${/TEX},K 2.97∼9.61 mg·{TEX}$kg^{-1}${/TEX}, and Ca 9.39∼28.23 mg·{TEX}$kg^{-1}${/TEX}. The amount of total N ranged from 0.003 to 0.286% in study sites. Soil chemical properties varied year to year and showed little tend. The research results showed that some characteristics of the artificial soil were changed after rooftop planting, i.e., soil pH and soil bulk density. Soil bulk density had a negative relationship with the coefficient of permeability, showing that the drainage condition might be limited after some period. This study suggests that a diversity of the research in the changes of the plant growth basis on the areas after construction.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.6
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• pp.50-59
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• 2014

This experiment was performed in order to study the relationship between physical properties of soil and the growth characteristics of Sedum reflexum. A correlation analysis and multiple regression analysis were performed using SPSS Ver 19.0 for Windows. The multiple regression analysis results of soil physical properties and growth characteristics were as follows. The regression equation: The length=$.993-14.070^*$(soil bulk density)+$.233^*$(solid phase)+$.038^*$(liquid phase)+$.068^*$(permeability). The significance of soil bulk density and solid phase was great. The width=$2.931-33.925^*$(soil bulk density)+$.566^*$(solid phase)+$.206^*$(liquid phase)+$.027^*$(permeability). The significance of soil bulk density and solid phase was great. The wet weight and dry weight of the upper and lower and soil physical properties did not have a direct relationship.

• The Korean Journal of Ecology
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• v.20 no.4
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• pp.265-274
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• 1997

All landscapes are mosaics of habitat patches of different types. Therefore, there are always edged between habitat patches in a landscape. Forest animal has an important role in vegetation development and maintenance by seed dispersal around forest. Movement of animals depends on the spatially heterogeneous structure and pattern of vegetation landscapes because each animal has special habitats in a landscape. Especially, forast edge with high permeability and prey density is one of the important habitats to the animals. Therefore, understanding the ecological characteristics of the forest edges as a corridor connecting mosaic vegetation patches is necessa교 새 establish the strategies for the nature conservation and sustainable vegetation management. Under this idea, we examined the animal influenced on pine seeds as one of the method of monitoring the animal activity in mosaic vegetation. Man-made mosaic vegetations including open, edge and inner forests were carefully selected in the rural landscape. We carried out predation test on pine seeds during one year. A result was that damages on seed was more significant at forest edge than inner and open forest. Pine seed on seedbeds was mainly attacked by squirrels and mice than birds. Pine seed was damaged by squirrels in different types of vegetation by seasons. Rate of seed predation at forest edge was, in special, higher than that of other sites. According to this results, it is suggested that the relationship between animal behavior and spatial vegetation structure relating to human impact such as the distance from settlement to vegetation appeares to be in the rural vegetation landscape.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.373-381
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• 2005

The permeability of contaminated soil and elapsed time are important considering factors to in-situ soil remadiation. Gabr et. al. (1996) derived the solution equation of contaminant concentration ratio as initial one (C/$C_0$) with time and spatial changes in contaminated area which embedded with vertical drains. The contaminant concentration ratio (C/$C_0$) is analyzed with time and spatial changes in three different permeability areas which are $k=l.0{\times}10^{-5,}$ $l.0{\times}l0^{-6,}$ $l.0{\times}l0^{-7}\;_{m/s}$ by using the Gabr's equation. Results from numerical analysis indicate that the ratio (C/$C_0$) decreases as the elapsed time increases in every point, however, remediation efficiency decreases as the analyzing point is far from injection well to extraction one and is deeper from top level of contaminated area. And also it decreases as the permeability of contaminated area decreases. Especially, the lower permeability of contaminated area effects directly on the soil remediation, in this research, under condition which the permeability of contaminated area is $l.0{\times}l0^{-7}\;_{m/s}$, the maximum time needed to attain 90% clean up level ($t_{90}$) is 65,690 hours(7.5 years), it takes so much time to clean the low permeability contaminated soil.

• Journal of Environmental Impact Assessment
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• v.17 no.2
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• pp.133-141
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• 2008

The loss, alteration, and fragmentation of habitat have led to a reduction of biodiversity. The growing awareness of the negative effects of habitat fragmentation on natural systems has resulted in conservation strategy that is concerned with not only population and habitat level but also ecosystem and landscape level. Especially, ecological network to link core areas or major habitat patches is one of the most important issues. Recently, landscape connectivity is increasingly used in decision making for fragmented landscape management in order to conserve the biodiversity in the regional scale. The objective of this study was to find potential forest as a ecological corridor in Go-yang city, Gyung-gi province using cost-distance modelling method that can measure connectivity based on animal movement. 'Least cost-distance' modelling based on functional connectivity can be useful to establish ecological network and biodiversity conservation plan. This method calculates the distance modified with the cost to move between habitat patches based on detailed geographical information on the landscape as well as behavioural aspects of the animal movement. The least cost-distance models are based on two biologically assumptions: (1) dispersers have complete knowledge of their surroundings, and (2) they do select the least cost route from this information. As a result of this study, we can find wildlife moving route for biodiversity conservation. The result is very useful for long-term aspect of biodiversity conservation plan in regional scale, because this is reflection of geographical information and behavioural aspects of the animal movement.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.2
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• pp.53-64
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• 2018

This study aims to quantitatively evaluate the conservation priorities of unexecuted urban parks in Seoul both from an ecological and public perspective. To this end, two methodologies, ecological network analysis based on graph and circuit theory and accessibility analysis, were employed in order to assess ecological connectivity of and public accessibility to unexecuted parks, respectively. This study applied linkage-mapping methods (shortest path and current flow betweenness centrality) of connectivity analysis to an integrated map of landscape permeability. The population-weighted accessibility to unexecuted parks was measured based on a negative exponential distance decay function. As a result, for both ecological connectivity and accessibility, Gwanaksan, Suraksan, and Bulamsan urban natural parks are found to be the most important (rank 1-3) to be conserved. For these sites, inner park areas with conservation priorities for connectivity and accessibility were identified. The findings of the study can be used for giving conservation priority to the unexecuted urban parks in terms of long-term sustainable urban planning.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.6
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• pp.97-114
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• 2019

This study aims to analyze the effect of urban ecosystem restoration projects by evaluating the short-term restoration performance of the project sites, from both qualitative and quantitative evaluations. In this study, for the qualitative evaluation, we derived the evaluation frame from previous studies and literature. For the quantitative evaluation, the changes in ecological connectivity after the restoration project were described using landscape permeability and network analysis. In addition, changes in habitat quality after the restoration project were evaluated by using InVEST Habitat Quality Model. These evaluations were applied to the three natural madang (ecological restoration) projects and two ecosystem conservation cooperation projects. As a result, three categories, 10 indicators, and 13 sub-indicators were derived from literature as the evaluation frame for this study. In the case of quantitative evaluation of restoration performance, habitat quality increased by 45% and ecological connectivity by 37% in natural-madang, and habitat quality by about 12% and ecological connectivity by about 19% in ecosystem conservation cooperation projects. This implies that the ecological restoration project can increase the ecological connectivity and the habitat quality of degraded sites even in a short period of time by improving the land-cover and land use. The results by applying the evaluation frame indicated that ecological and environmental factors and the ecological functions were improved by the restoration works, even though the magnitude of performances were diverse depending on the specific evaluation items, project type, and site characteristics. This study clarified that the success of ecological restoration project should be assessed by both of the short-term and long-term goals, which can be achieved by the maintenance and sustainable management, respectively.