This paper is the result of mineral exploration engineering.

Objective Cracking the contradiction between energy security and ecological environment protection is a major challenge for the development of coal resources in ecologically fragile areas. The large−scale and intensive extraction of coal resources not only triggers rapid changes in geological conditions but also impacts the structure and function of the Earth's critical zone in mining areas. The Earth's critical zone refers to a continuous domain that extends upwards from the bottom of groundwater or soil rock interface to the top of vegetation canopy.

Methods Focusing on how to understand the relationship between the operation of the Earth's critical zone and the evolution of geological conditions for coal development, based on the analysis of coal mining geological conditions and the response of the Earth's critical zone, this paper elucidates the response mode, monitoring technology, prediction methods, guarantee strategies, and loss reduction work of the Earth's critical zone in coal mining affected areas. Based on the evolution of geological conditions for coal resource extraction and the protection of the Earth's critical zone, this paper systematically analyzes the theory and technology of reducing losses and ensuring coal development in the Earth's critical zone from four aspects: scientific connotation, scientific problems, research ideas, and guarantee plans.

Results The overall approach of the research on the response of the Earth's critical zone to coal mining is structured as "Pre−mining geological conditions and key zone structures and elements → Geological condition changes and the Earth's critical zone response modes and evolution status identification → Full time and space active and passive multi−source information response and dynamic monitoring → The Earth's critical zone structure functional dynamic evolution model and intelligent prediction evaluation →The Earth's critical zone loss reduction geological guarantee strategy and restoration reconstruction integrated technical method". The research content includes: (1) Identify the comprehensive characteristics of mining geological conditions such as geological structure, hydrogeology, rock layer combination, and crustal stress with coal occurrence, reveal the spatial relationship characteristics of the Earth's critical and lower coal seams, rock layers, and groundwater, and finely characterize the critical zone with multiple elements, modes, and scenarios, forming a fast query and intelligent analysis digital platform including environmental bearing capacity indicator system, evaluation model, and bearing capacity zoning. (2) Analyze the connection between fracture fields of rock (soil) layers under the impact of mining and the hydrological cycle of critical zones, revealing the synergistic evolution mechanism of geological conditions and critical zones and proposes methods for identifying the response patterns of the Earth's critical zone to coal development.(3) Investigate the temporal and spatial evolution of rock layer structures, fracture networks, seepage channels, stress−energy concentration characteristics, material cycles, energy exchanges, and the multi−source information field under mining factors and construct the spatial−temporal information response model of the Earth’s Critical Zones under the whole life cycle of coal development. (4) Construct a spatial and multi−directional multi−source information fusion monitoring system for the space−sky−earth−drill−well under the conditions of the whole life cycle of coal mining, form a monitoring and analysis system for the interfacial structure and operation process elements of the Earth's critical zone under the influence of coal mining and predict the structural changes, response patterns, operational processes and ecological and environmental effects of the Earth's critical zone in the coal development zone. (5) Propose technologies such as collaborative development of coal and coal measures resources, comprehensive utilization of mine water, and large−scale utilization of underground space in coal development, functional reconstruction. Establish a geological condition and critical zone structure monitoring technology based on multi−source information, achieving "transparency of geological structural conditions, digitization of key damage elements, informatization of evolution process monitoring, intelligent model prediction, and precision of critical zones protection technology".

Conclusion The geological guarantee of the Earth's critical zone covers geological conditions, mining modes, monitoring systems, prediction methods, and loss reduction technologies. It pursues the coordinated development of coal safety mining and geological environment protection, solves the contradiction between resource development and geological environment constraints, improves the theory and technology of comprehensive development of coal and coal bearing resources in ecologically fragile areas, and the protection, restoration, and reconstruction of the Earth's critical zone functions. It provides a scientific basis for geological, mechanical, and physical foundations to build a resource−saving and environmentally friendly society, and promotes the in−depth development of coal engineering practice and safety theory.