Analysis on landscape pattern change and driving forces of Liqiu River basin in Kangding, Sichuan Province

Liqiu River is an important tributary of the middle reaches of Yalong River. Under the background of regional socio-economic development and Yalong River hydropower construction, it is of great significance to study the landscape pattern change of Liqiu River basin and explore the driving factors of landscape change. Based on the landscape distribution data of Liqiu River basin in 2006 and 2022, the research was conducted by using ArcGIS and Fragstats software platforms. The results showed that: (1) Shrub, grassland, and forest were the main components of the watershed landscape, with the largest distribution area of shrub, the largest average patch area of forests, and the highest patch number and density of grassland. (2) From 2006 to 2022, the patch area with changed landscape type attributes in the study area was 2390.06 hm², accounting for 0.46% of the study area. Natural landscapes such as forest, shrub, grassland, and wetland were transferred to artificial landscapes such as urban land and farmland, and the area of urban landscape increased by 2172.10 hm², with an increase of 166.01%. (3) The patches of shrub, grassland, unused land, and forest had low dispersion and high adjacency. Grassland patches had the maximum mixedness. Wetland patches had the most complex shapes and edge folds, and the highest connectivity. The shape and edge of farmland and urban land patches were the simplest, and the patch dispersion degree was higher. In the past 16 years, the number of landscape patches in the basin had increased, while the average patch area had decreased. Patches of the same landscape type had become more dispersed, mixed, and functionally disconnected, resulting in an upward trend in the fragmentation, evenness, and diversity of the basin landscape. The expansion and increase in intensity of human activities were the main driving factors for landscape change in the basin. Based on the above results, reasonable control and scientific planning of construction land, as well as measures to mitigate human interference and expansion, are put forward to maintain the landscape stability in Liqiu River basin.