[Evaluation of land ecosystem health in Shaanxi Province, Northwest China based on PSR Model.]

Based on the pressure-state-response (PSR) model and entropy method, we analyzed the health status of land ecosystem and the temporal and spatial variations from 2009 to 2017 in ten cities and one district in Shaanxi Province. The driving factors affecting the health of the land ecosystem was examined. Results showed that during 2009-2017, the overall health of the land ecosystem in Shaanxi Province was improved, which was lower during 2009-2014 and being obviously improved after 2014. The health level of land ecosystems in Xi'an, Baoji, Weinan and Hanzhong was high and with substantial variation, while that in Yan'an, Yulin, and Ankang was low and stable, decreasing in order of South Shaanxi, Guanzhong region and North Shaanxi. Overall, the pressure, state and response indices of the land ecosystem in Shaanxi Province increased during 2014-2017 with a gentle growth, which were basically flat after 2014. Those results indicated that the land ecosystem in Shaanxi Province was at a stable and healthy state. Population growth, urbanization level, fertilizer load per unit of arable land, forest coverage rate, industrial wastewater discharge compliance rate and comprehensive utilization rate of industrial solid waste were the main driving factors for the health of land ecosystems in Shaanxi. Controlling the use of fertilizers and pesticides, optimizing the structure of land use and improving land use efficiency are necessary strategies to promote the construction of ecological civilization and implement the red line of ecological protection for Shaanxi Province.