Dr. Zhifeng Yang is an expert of environmental sciences. Dr. Yang has long-term been working in the field of environmental sciences, especially in water management system in river basin and urban ecological planning and management, which relate close to each other.
In the field of water management system in river basin, he established principles, guidelines and index system of environmental flows assessment for various ecosystems like wetlands, rivers and lakes, etc., and initiates the threshold theory of environmental flows. He also proposed water resources renewability theory, the evaluation indices and methodologies.
Regarding its important role in the whole basin and even the larger region, much attention was paid to urban ecosystems by Dr. Yang, which is proved to be the center of production and human living.
He improved the quantitative simulation for urban ecological relationship and dynamic simulation for ecological process. He also established a series of urban ecosystem assessment methods including health evaluation, limiting factor analysis, and ecological carrying capacity assessment.
Based on these simulation and assessment methods, the urban ecological planning and regulation technique was further developed while integrating factors of resources, environment, society and economy with the perspective of urban ecological relationship and process.