Exploring the multidimensional synergistic evolution mechanism of green watershed policies in China: A network analysis approach

Building green watersheds is crucial for achieving integrated ecological and socio-economic development in China. Policy synergy plays a key role in ensuring the effective implementation of environmental strategies. However, research on policy synergy in green watersheds remains limited. This study investigates the temporal dynamics of policy synergy using 464 national-level policy documents (1997–2024) and focuses on key themes such as pollution reduction, carbon reduction, greening expansion, and economic growth. A multidimensional analytical framework is developed to examine the synergistic evolution of green watershed policies across three dimensions: policy tools, policy objectives, and their linkages. Policy synergy is quantitatively assessed across three dimensions using text mining and network analysis. The findings revealed that synergy among policy tools, policy objectives, and their linkages strengthened from 1997 to 2017 and then gradually declined after 2018. Tool synergy evolved from bottom-line control to high-quality empowerment through three stages: government-led tools, mechanical combinations, and organic synergy. Policy objective synergy indicated a transition from a singular focus on pollution reduction to a more integrated, multi-objective framework. Tool–objective synergy highlighted the differentiated applicability of specific tools to distinct policy objectives. This study introduces a novel analytical framework for policy synergy analysis and provides methodological and empirical guidance for designing green watershed policies in China and other developing countries.