Spatiotemporal Analysis of Urban Impervious Surfaces in Karst Areas over the Past 40 Years Based on GIS Technology

The distribution scale, spatial pattern, and changes in impervious surfaces are important indicators affecting regional ecosystems and environmental changes, playing a crucial role in urban construction and ecological environments. However, there has been a significant lack of long-term spatiotemporal analysis of impervious surfaces in Guizhou Province, which is predominantly characterized by karst landforms. This study uses methods such as ArcGIS spatial analysis, expansion rate, expansion intensity, and standard deviation ellipses to conduct an in-depth analysis of the temporal changes, spatial characteristics, and expansion trends of urban impervious surfaces in Guizhou Province from 1985 to 2022. The main conclusions are as follows: (1) The impervious surface area in Guizhou Province has shown a significant growth trend, increasing from 386.41 km2 in 1985 to 1401.86 km2 in 2022, with an accelerated annual growth rate, especially after 2000, when the growth significantly increased; (2) The expansion of impervious surfaces exhibits phased characteristics, with slower growth in the early stages and a notable acceleration in the expansion rate after 2000, particularly during the 2010-2022 period; (3) The spatial expansion of impervious surfaces has spread from urban cores to surrounding areas, transitioning from a point-like to a surface-like distribution; (4) The expansion patterns differ across various cities and prefectures, with notable expansion in Guiyang, Zunyi, and Tongren, and significant spatial differences in the standard deviation ellipses, especially in Zunyi. This study provides data support for further understanding the relationship between urbanization and ecological environment changes in Guizhou Province and offers a scientific basis for urban planning and water resource management.