A senior environmental expert has called on local governments along the Yangtze River to improve their remote sensing-based aquatic ecological monitoring capabilities, as China plans to introduce an environmental evaluation and assessment mechanism that no longer focuses on pollution control in the basin of Asia's longest watercourse.

Based on pilot programs this year and the next, the nation will commence establishment of the new mechanism, which prioritizes the health of ecosystems rather than the intensity of major water pollutants. The programs will kick off in 2025 and will involve 50 key water bodies in the 17 provincial-level regions in the Yangtze basin, according to a guideline issued by four central government bodies, including the Ministry of Ecology and Environment, in late June.

Gao Jixi, head of the Center for Satellite Application on Ecology and Environment, said that to ensure the pilot programs can be carried out in a meticulous and effective manner, the general aquatic ecological conditions in the Yangtze must first be determined.

A key task in the work is to conduct a survey on the aquatic habitats — the core of aquatic ecosystems — analyze their conditions and problems and then establish a database of the information collected, he noted.

Gao stressed the key role of satellite remote sensing in the survey as, unlike traditional ground environmental sampling and monitoring, it can cover a vast region and thus cover each aquatic habitat in the basin.

Remote sensing has also been widely applied in the monitoring of shorelines, algae and water blooms and aquatic plants, he said.

Although an integrated space- and ground-based system mainly supported by remote sensing has been the general monitoring method employed at the national level for aquatic habitat monitoring, local governments need to beef up their capacity to conduct such monitoring, Gao said.

He said they should make consistent efforts to also gradually develop tower-based remote sensing and promote the use of drones and vehicles to carry monitoring equipment to improve their space-ground monitoring network.

The application of these facilities can help them develop an all-around monitoring system that is highly precise with minimum monitoring gaps, and thus manage to rapidly detect changes in aquatic habitats and roll out tailored management measures accordingly, he said.