지속가능한 농촌경관자원 관리를 위한 토지평가
Land evaluation for the management of sustainable rural landscape resources
조경술 농촌경관자원 토지평가;
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The purposes of this study are to construct a Land Utilization Type(LUT) map in the basis of a digital topographic map and satellite image for analyzing the land resources in a rural district and to propose the district-level land evaluation method with a consideration of land use limitations and land use requirements. A process on the land evaluation is for conserving the rural resources and maintaining the rural landscape. LUT is a basic data for understanding the specific land use in study area. LUT map was constructed by using the digital topographic map and a field survey. Fallow fields and flooded regions were also identified by an on-site field survey and interview. Fallow probability, one of the limitation factors, was analyzed by logistic regression analysis. The data, used in this analysis, was a field-surveyed data. As a result, the area of highly suitable land(S1) was 1,304.76ha and suitable land(S2) was 2,161.15ha and marginally suitable land(S3) 1,155.21ha. Especially most of these regions were located on a hillside with a steep slope and they existed as patches which were distinct from forest, therefore a plan for the management of a continuous landscape was needed. Potential soil erodibility index(PSEI) was derived from USLE equation. The area of not suitable land(N1) was 45.98ha in orchard, 25.85ha in fallow upland and 18.20ha in single cropping upland. PSEI was much higher in steep uplands and orchards. Flood hazard potentiality was explained by logistic regression analysis and piece-wised regression analysis. The result of suitability analysis by the potentiality of flood hazard was that the area of N1 was 194.91ha, absolutely not suitable land(N2) was 60.89ha. These lands had good conditions for the cultivation, however, had much possibility to be inundated. So it was necessary to manage the landscape disturbed by the flood. As a result of analysis of land suitability, the area of S1 was 83.34ha in Hyunchang-ri, 72.75ha in Jangcheon-ri and 51.98ha in Chogok-ri. The area of S2 was 106.38ha in Chogok-ri, 92.30ha in Jangcheon-ri, 83.68ha in Okcheon-ri and 79.38ha in Seok-ri. Most of these areas were located near the Nakdong river, land usability such as water supply and accessibility to roads was much higher than other farmlands. These unfair areas had some limitations such as fallow, soil erosion, inundation, then the methods of landscape management were proposed in unfair area for an innovation of disturbed landscape. These unfair condition caused the landscape disturbance in the unfair area. Several methods for the qualitative renovation of the disturbed rural landscape was proposed. Crops for a special use were proposed to be planted at a low-level unfair area, native plants at a mid-level unfair area and intended fallow at a severely unfair area were proposed with the object of the replacement or restoration to the natural vegetation. The unfair regions nearby a swamp or a river were proposed as a buffer zone for protecting them. With the change of landscape structure in the unfair area by this proposition, the changes of landscape structures between pre-restoration phase and post-restoration phase were compared by FRAGSTATS which is landscape assessment program. The numbers of patches were increased from 117 to 132 in forest, 1 to 4 in fallow orchard and 211 to 284 in orchard, The increment of patches in forest resulted from severance between edge patches because of importation of new forest patches. The increment of patches in orchard resulted from disconnection between orchard patches fragmented by increment of forest patches. Finally, the potentialities of fallow, soil erosion and flood hazard are much more important factors as limitations for the land use in agricultural lands. These factors could be explained by logistic regression model and must be selected as basic variables for the land suitability in the agricultural lands. Land suitabilities according to the land use such as a cultivating condition of the specific crop in agricultural area could be quantified by categorical regression model(CRM). This models, derived from CRM, could be used for agricultural purpose as a way to protect agricultural area of good quality and to restrict appropriation to other uses. In addition, establishment of unfair area by land suitability assessment could review the disturbed landscape, and the proposed landscape management plan for the unfair area was expected to be used as the proper way to manage the sustainable rural landscape.