Abstract:

Karst Critical Zone (KCZ) extends across lithosphere, hydrosphere, pedosphere, atmosphere and biosphere. Understanding the structure, characteristics and hydrogeochemical processes of KCZ is a key issue in the scientific research on Earth’s Critical Zone as well as karst hydrology. Based on summarization of relevant research results obtained at home and abroad, this paper analyzed the hydrogeochemical connotation, KCZ hydrodynamic vertical zoning, and hydrogeochemical processes and mechanisms under KCZ framework, and explored the law and evolutionary mechanism of hydrogeochemical process of KCZ under changing environment. Futher, this paper pointed out the shortcomings and problems in KCZ research. The current work is within the scope of traditional karst groundwater research. It does not consider the hydrogeochemical process and its coupling relationship between the plant canopy and the karst aquifer from the perspective of KCZ framework system, neither has it considered the potential impacts of epochal factors, such as introduction of new pollutants, in-depth implementation of big data methodology, and gradual changes in global carbon emission paths, on karst hydrogeochemical research. Future researches may focus on hydrogeochemical study of new pollutants based on framework; karst hydrogeochemical study based on big data system; karst hydrochemical study under the “dual-carbon strategy”; material transformation and energy transfer processes and their coupling driven by KCZ hydrogeochemistry; and integration of high-resolution monitoring, evaluation and simulation approaches in KCZ research.

Key words: Karst critical zone, hydrogeochemistry, research progress, big data, dual carbon strategy