China has invested nearly 900 billion yuan in transfer payments for the conservation of water sources, biodiversity and other aspects in the national key ecological functional areas (NKEFAs), involving 810 counties and approximately 4.84 million square kilometers, which accounts for 50.4 percent of the country's land area, according to the Ministry of Ecology and Environment (MEE).

NKEFAs are important ecological barriers for the country. The Chinese government has implemented transfer payment policies for NKEFAs since 2008. Dozens of management measures have been adopted with strict evaluation mechanisms.

To ameliorate the monitoring and evaluation process, the MEE has established an integrated monitoring network.

High-resolution satellite imagery is applied in ecological types like woodlands, grasslands and water bodies; drones are deployed for systematic, three-dimensional and dynamic monitoring.

So far, 85.8 percent of the counties with NKEFAs exhibit good ecological quality.