Related studies analyzing the spatial structure of soil moisture from both horizontal and vertical directions, as well as the spacing interval distances of soil moisture sampling points in typical karst demonstration zones, are relatively rare. This study applied classical statistics, geostatistics, and “3S” technology to analyze the spatial structure, influencing factors, and spacing interval distances of soil moisture sampling points in the Guohua Demonstration Zone. The results showed that Moran’s I indices of soil moisture at different soil depths in the Guohua Demonstration Zone presented positive spatial correlation, and the spatial distribution of soil moisture at different soil depths showed a distinct spatial clustering pattern, with few spatially isolated zones. The spatial autocorrelation distance for soil moisture at 5 cm and 10 cm soil depths was 2400 m, while the autocorrelation distances for soil moisture at 20 cm and 30 cm soil depths were 2200 m and 2000 m, respectively. The spatial range value for soil moisture at a soil depth of 20 cm in the Guohua Demonstration Zone was the largest (Range = 6318.0 m), while the spatial range value for soil moisture at a soil depth of 30 cm was the smallest (Range = 646.0 m). The minimum value (threshold: 646.0 m) between the spatial autocorrelation distance and the spatial range of soil moisture at different soil depths in the Guohua Demonstration Zone could serve as an appropriate spacing interval distance of soil moisture sampling points. Soil moisture at different soil depths in the Guohua Demonstration Zone was primarily influenced by rock desertification, vegetation cover, soil layer thickness, and elevation. The synergistic effect of “rocky desertification + vegetation”, “rocky desertification + soil thickness”, and “vegetation + soil thickness” had a greater influence on soil moisture. Through high-density soil moisture sampling points in typical karst areas, the study results strengthened the application research on soil moisture in typical karst areas, providing scientific references for studies on the spatial structure, influencing factors, and appropriate spacing interval distance of soil moisture sampling points in karst areas.

The level and speed of regional economic development are closely intertwined with transportation infrastructure. In the context of limited resources, the mutual adaptation of economy and road construction is crucial for achieving maximum efficiency. To probe into the mutual influence between county economies and their road infrastructure in underdeveloped and developed counties, this study employs the coupling coordination degree model to explore the coordinated development of the county economy-road system. Detailed data analysis reveals significant differences in the coupling coordination degree of the economy-road system among different counties in China. Overall, the development of the economy and roads is still in a phase of mutual adaptation, indicating immense potential for future improvement. In terms of coupling degree, developed counties exhibit a benign mutually reinforcing trend between their economy and road development, while underdeveloped counties remain in a period of mutual adjustment. In terms of coordination degree, the overall coordination level of the economy-road system in developed counties is superior to that of underdeveloped counties. Additionally, the study finds that over half of the counties are ahead in road construction compared to their economic development. Developed counties’ economies can better match their road construction levels, while underdeveloped counties’ economies lag significantly behind their road construction progress.