개발제한구역 훼손지 탐색 및 생태적 연결성을 고려한 자연환경복원 우선순위 평가

개발제한구역 훼손지의 생태적 복원 우선순위를 평가했다.

Since the 1960s, industrialization and urbanization have led to a concentration of population in large cities nationwide. To address the uncontrolled expansion of major cities, including Seoul, and the resulting issues related to traffic, housing, and environmental pollution, Development Restriction Zones(Green Belt) were established. Green Belt are designated zones where urban development is restricted to prevent disorderly urban sprawl, preserve the nature surrounding cities, and ensure a healthy living environment for urban residents.

As of December 2023, there are seven such zones across the country (the Seoul Metropolitan Area (SMA), Busan, Daegu, Gwangju, Daejeon, Ulsan, and Changwon) covering a total area of 3,789 ㎢. Within these Green Belt, only minor activities related to residents' housing, living convenience, and livelihoods are permitted, while any land use changes, development activities, or urban planning projects that conflict with the designated purpose are prohibited. Activities that align with the designated purpose may proceed, but only with permission from local governments, leading to stricter land use regulations compared to other regions.

Green Belt have played a significant role in managing the growth of major urban areas in South Korea over the past decades. However, the landscape within these zones has become increasingly fragmented due to ongoing urban expansion, rising development pressures, exacerbated by human interference and damage. While the environmental and ecological value of Green Belt may be low in absolute terms, their relative importance can be higher due to their proximity to urban areas. Initially established to curb urban expansion regardless of their ecological attributes, these zones have been subject to ongoing adjustments and deregulations.

Therefore, it is crucial to consider the environmental and ecological values of these regions when setting criteria for such actions. Recently, discussions on easing regulations in Green Belt have escalated, leading to the deregulation of certain zones and the institutionalization of new designations for areas that receive high environmental assessment ratings. This necessitates further consideration of the environmental and ecological values both within the Green Belt and in adjacent external regions, as well as the connections and linkages between these areas.

In this study, the SMA Green Belt experiencing nature degradation due to land use changes were identified and alterations in ecological connectivity were assessed quantitatively and spatially. Finally, changes in ecological connectivity resulting from the nature restoration in each degraded area were predicted and evaluated, with the objective of establishing priorities for nature restoration.

Identification of Nature Degraded Areas In this study, areas that were formerly forests, grasslands, and wetlands of high ecological value but have structurally and functionally degraded due to various factors are classified as areas of diminished ecological value, such as miscellaneous grasslands and barren lands. In the SMA Green Belt, a total of 910 sites covering 5,875,053 ㎡ were identified as degraded areas. This accounts for only 0.45% of the total area, which encompasses 1,317.91 ㎢.

It was observed that a large number of degraded areas are distributed along the boundaries and adjacent regions both within and outside the SMA Green Belt, while fewer degraded areas are found in the inner regions where the zones are relatively wide. The average size of each degraded area is 6,456.10 ㎡, with small-scale degraded areas of 10,000 ㎡ or less accounting for 88.79 % of the total number of sites. Based on a large-scale land cover map before degradation, forest areas accounted for 52.49 %, agricultural areas for 24.91 %, and grasslands for 14.64 %. However, due to degradation, the composition shifted to 55.97 % grasslands, 19.78 % barren land, and 14.28 % agricultural areas.

Consequently, the proportions of forested and agricultural lands decreased by 48.49 % and 10.62 %, respectively, whereas grasslands and barren land increased by 41.32 % and 17.93 %, respectively. Using the pre-degradation land cover map, the degraded areas can be classified into five types: areas degraded from forest regions (Type 1), areas degraded from grasslands (Type 2), areas degraded from wetlands (Type 3), areas degraded from agricultural regions (Type 4), and areas degraded from other land uses (Type 5).

It was observed that (Type 3) areas tend to be relatively large in size, while the extent of damage in the other types varies based on the current intensity of land use and level of management. Landscape Connectivity Analysis To assess ecological connectivity, a landscape connectivity analysis was conducted using Omniscape.jl. This analysis accounted for the links between habitats both inside and outside the study area. A 5㎞ buffer zone was established around the study area's boundary, and the entire internal area was set as the study scope. Large-scale land cover maps were created for the periods before degradation (past) and after degradation (present).

For the future land cover map (post-restoration), it was assumed that conditions would recover to their pre-degradation state, and the past land cover was overlaid onto the current map to create a predicted cover map. Based on this, resistance surfaces were developed, and the analysis was conducted. The analysis indicated that due to nature degradation, the cumulative current flow within the Green Belt decreased by approximately 7.78 % (76.158 → 70.238). In the 910 degraded areas, the cumulative current flow decreased by approximately 47.71 % (66.672 → 34.861).

Furthermore, when comparing the current landscape connectivity with the future scenario (SC3) in which restoration is implemented across all degraded areas (0.45 % of the total Green Belt), it was found to increase by 0.31 % (70.238 → 70.457). This indirectly confirms that, in