Abstract: The increases of human activities threaten the health of the earth's ecosystem, and pre-sent a big challenge to regional sustainable development and environment conservation. How to maintain a safe ecological environment together with social and economic development is an important issue for sustainable development. Under the theoretical framework of “safe and just operating space”, we integrated lake sediment records, environmental monitoring data, and socio-economic data in Liangzi Lake Catchment, analyzed the status of key eco-environmental processes and achievement degree (the completion of the current value of social basic indicators relative to the target value) of residents' social welfare, and constructed a “safe and just operating space” for the sustainability of local social-ecological system. The results showed that the indicators including freshwater utilization, cultivated land resources, air quality, soil and sediment regulation, and chemical pollution in the catchment had exceeded the environmental ceiling and were at the “dangerous” level, which should be regulated in the future. As for the social welfare, the achievement degree of clean water, sanitation facility, and industrial innovation were relatively low. The per capita GDP was negatively correlated with soil and water conservation and air quality, indicating the negative effects of social and economic development on water, soil, and air. With multi-source environmental data, especially long-term limnological records, we effectively reconstructed the historical environmental change process, revealed the deficiency of environment and residential well-being in local social ecosystem management, which would provide important insights for regional sustainable development.

Key words: safe and just operating space, Liangzi Lake Catchment, lake sediment record, environmental ceiling, sustainable development.