The Yangtze River, often referred to as the mother river of China, is vital to both ecological functions and the economic and social development of the region. In a new study published in Water & Ecology , Dr. Dianchang Wang from the National Engineering Research Center of Eco-environment in the Yangtze River Economic Belt, China Three Gorges Corporation, led a research team to explore the evolutionary characteristics of the water ecological pattern in the Yangtze River Basin over the past century.
The key findings of the study include:
- The area of lake wetlands in the middle and lower reaches of the Yangtze River has been on a downward trend, shrinking from 26,020 km2 in the 1930s to 14,400 km2 currently, with a shrinkage rate of 44%.
- The sediment flux in the mainstream of the Yangtze River has shown a downward trend since the 2000s. The fluxes of chemical oxygen demand, ammonia nitrogen, and total phosphorus in the mainstream showed a upward trend after the 1980s and went down after the 2010s;.
- The number of four prominent domestic fishes (black carp, grass carp, silver carp and bighead carp) in the Yangtze River showed a downward trend after the 1960s and went up after the 2010s.
The team also found that the evolution of the water ecological pattern in the Yangtze River Basin over the past century was divided into four stages.
Stage 1 (before 1940s): The evolution of the water ecological pattern in the Yangtze River was primarily a natural process driven by the natural scouring and siltation of the river-lake system.
Stage 2 (1950s to 1970s): Affected by large-scale agricultural reclamation due to rapid population growth, the evolution of the water ecological pattern in the Yangtze River was mainly characterized by a significant shrinkage of river-lake water and wetland spaces in terms of physical attributes.
Stage 3 (1980s to 2000s): Influenced by increased pollutant emissions and large-scale ecological disturbances brought about by rapid industrialization and urbanization, the evolution of the water ecological pattern in the Yangtze River was mainly manifested by a decline in water environmental quality and a reduction in the number of aquatic species in terms of chemical and biological attributes.
Stage 4 (after 2010s): Driven by the green transformation of economic and social development in the basin and the ecological protection and restoration activities in the Yangtze River resulting from a shift in the understanding of the relationship between humans and nature, the evolution of the water ecological pattern in the Yangtze River is primarily characterized by a gradual and comprehensive recovery and improvement in the health of the water ecosystem.
The researchers proposed water system governance strategies aimed at harmonious coexistence between humans and nature in the new era, as follows:
- Establish a"nature - engineering" coupling governance system to promote the coordination of engineering and nature.
- Strengthen species conservation and habitat restoration to enhance biodiversity, stability, and sustainability.
- Develop green and ecological circular agriculture and shift from "pollution control" to "resource recycling".
- Promote the urban "water operator" mode to improve the quality and efficiency of urban water management.
