Spatiotemporal changes in landscape patterns in karst mountainous regions based on the optimal landscape scale: A case study of Guiyang City in Guizhou Province, China

Abstract

The accurate analysis of landscape pattern and ecological process characteristics in rapidly urbanized areas is crucial for formulating policies related to differentiated urban development and landscape management measures. However, there are no convincing set of overall indices suitable and the optimal scale in karst mountainous regions. This study determined optimal landscape indices and scales and analysed the temporal and spatial variation characteristics of landscape patterns in the karst mountainous city of central Guizhou Province by taking Guiyang City as a case study area using Principal component analysis and inflection point analysis. The results show that: (1) the nine landscape indices (i.e., edge density (ED), mean radius of gyration (GYRATE_MN), mean contiguity index (CONTIG_MN), mean shape index (SHAPE_MN), contagion index (CONTAG), interspersion and juxtaposition index (IJI), Shannon's diversity index (SHDI), proportion of urban area (UI), Gibbs-Martin diversity index(GM)) were optimal indices of landscape pattern analysis in karst mountainous cities, with optimal landscape grain and extent of 90 m and 1000 m, respectively; (2) from 1995 to 2019, the landscape pattern in karst mountainous region has changed dramatically under the impact of rapid urbanization, and urbanization and ecologization were main trends of landscape pattern changes; and (3) the landscape fragmentation was intensified with the regularity tendency of patch shape, which is still facing severe challenges to the protection of regional ecological environment. This study makes important contributions to exploring the response between landscape pattern changes and ecological processes and promoting ecological sustainable development in karst mountain cities.