Redai dili (Mar 2023)
Urban-Mountain Coupling Characteristics Based on Landscape Form and Its Disaster Effects: A Case Study of the Guangdong-Hong Kong-Macao Greater Bay Area
Abstract
With the advancement of urbanization in China, hilly and gently sloping mountainous areas have become areas of high disturbance owing to urban construction, with the disturbed areas also having a high incidence of mountain disasters. The large hilly and shallow mountainous areas in the Guangdong-Hong Kong-Macao Greater Bay Area are continually disturbed by rapid urbanization, with frequent geological disasters. This study attempts to reflect the boundary morphology of the interaction zone from the perspective of the landscape morphology of the town-mountain interaction zone by using the landscape pattern index, analyzing the relationship between the morphological index and the intensity of geological disasters, and identifying the key factors. Finally, the functional relationship is fit between the intensity of disasters and the landscape pattern index based on the GAM model to reveal the interaction characteristics of towns and mountains and the disaster effects caused by them. The results of the study show that: 1) the urban-mountain interaction zone in the Bay Area is located in Guangzhou, Shenzhen and Hong Kong, with an area of 131.8, 81.6 and 58.5 km2 respectively, primarily in areas with a high proportion of hilly and shallow mountainous areas and rapid urban development; 2) Shenzhen and Hong Kong had higher landscape pattern indices than other regions, while Jiangmen, Zhaoqing, Foshan, and Huizhou generally had a lower landscape pattern index; 3) Among the nine landscape pattern indices, seven were positively correlated and two were negatively correlated, with CONNECT showing the highest correlation of 0.84 (P<0.001), SPLIT showing a high negative correlation of -0.84 (P<0.001), and AREA and PARA showing a weak correlation; 4) Most of the edge indicators, shape indicators, and agglomerative landscape index had linear relationships with landslide hazard frequency, and the frequency decreased with an increase in LSI and SPLIT and increased with the increase in GYRATE, SHAPE, FRAC, PARA, and CIRCLE; and 5) The larger the area of the urban-mountain interaction zone, the more complex the shape; the longer the boundary length, the more irregular the shape of the interaction zone; and the smaller its closeness to a circle, the more fragmented the interaction zone patches, the higher the ratio of core patches to the total area of the interaction zone, and the higher the probability of landslide disasters. Combined with the results, from the perspective of the construction of a single project in a small area, the larger the scope of excavation to the mountain, the more tortuous and complex the engineering cut, and the higher the probability of triggering landslides and collapses. For large-scale continuous construction projects, the closer the cuts are to each other, the higher the degree of agglomeration, the larger the area occupied by the core project, and the more likely it is to trigger geological disasters. This study is significant for understanding and mastering the heterogeneity law of geological hazards under different land use degrees and configuration measures, which can serve as a guide for land structure adjustment and optimize land use layout more effectively. It is of great practical significance for ecological restoration, sustainable and rational use of land resources, geological hazard prevention and control, and enriches the geological hazard susceptibility evaluation system.
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