Evaluation and structural analysis of the functions of the Tibetan Plateau National Park Cluster

National parks are useful entities for looking at coordinated efforts to improve the Tibetan Plateau’s function as an ecological safety barrier and the region’s green development.Research on the characteristics of the function structures of the Tibetan Plateau’s national parks is vital to promoting their systematic and coordinated development.This paper combines the pressure-state-response model,the rank-size rule and a coupling and coordination model to identify and evaluate the functions of national parks on the Tibetan Plateau and to analyze the categories,hierarchy and structures behind those functions.The results indicate the following:(1)The Tibetan Plateau National Park Cluster needs to maintain internal and external relations.Internally it needs to rationally allocate resources between ecological protection,recreation and community development,and externally it needs to promote its role as an ecological security barrier and promote regional green development by rationally ranking and organizing the individual national parks,so as to handle their co-evolution of functions at multiple scales.(2)Ecological protection,recreation and community development are the most prominent functions of the Tibetan Plateau National Park Cluster,but there is scope to develop their scientific research and education functions.The Zipf index shows that their multi-functional level conforms with the rank-size rule,indicating balanced development.Individual national parks need to strengthen their optimal functions according to their characteristic localization.(3)The degree of coupling between the functions of the Tibetan Plateau National Park Cluster is 0.7809,and the degree of coordination is 0.6227,which indicates a very strong coupling and moderate coordination.The coupling strength and degree of coordination between the multiple functions vary greatly among the individual national parks,which reflects their different function structures.There are four function structure types:fully coordinated,optimally developed,moderately developed and moderately underdeveloped.This study contributes to research on evaluating the functions of national park clusters and analyzing their structures,and it serves as a reference on optimizing and sustainably developing the Tibetan Plateau National Park Cluster.