I. Mine Area Topographic and Geological Map: Precise Mapping of 3D Geological Space

(1) Basic Elements and Core Functions

In underground mining, topographic and geological maps play an extremely critical role—they are essentially the "spatial blueprint" for underground mining operations. These maps are far more than mere visuals; they integrate crucial information on both terrain features and geological structures, providing an indispensable foundation for making informed decisions throughout the mining process.

From a topographic perspective, the precision requirements are quite high—contour lines are typically annotated with accuracy no lower than that of a 1:2000 scale, ensuring that even subtle terrain undulations are accurately depicted. The coordinate grid employs the Gauss-Krüger projection by zone, guaranteeing precise representation of geographic locations and providing a solid foundation for subsequent surveying and positioning tasks. Additionally, the annotation of hydrographic features is exceptionally detailed, covering rivers, lakes, wells, springs, and other water bodies—all of which not only influence both production and daily water usage at the mine but may also play a critical role in shaping and distributing mineral deposits. Equally important are the annotations of surface buildings and structures, as these are closely tied to mining operations. For instance, the location of facilities such as workshops and warehouses directly impacts the planning of transportation routes and the layout of equipment.

At the geological level, the presentation of stratigraphic boundaries is crucial, requiring clear annotations of age, lithology, and other relevant information. This helps in understanding the evolutionary history of strata and the processes involved in the formation of geological structures. Accurately defining ore-body outcrops is essential, as it visually highlights the extent of mineralized zones, providing direct clues for both mineral exploration and mining operations. Equally important is the distinction and annotation of fault structures—specifically, clearly identifying normal versus reverse faults and accurately documenting their orientation parameters—since these factors are critical for analyzing the occurrence state of ore bodies and ensuring safe mining practices. Lastly, delineating magmatic intrusions is equally vital; dividing intrusion zones into distinct lithological bands not only reveals patterns of magmatic activity but also sheds light on how such events have influenced surrounding geological formations.

Taking a certain metal mine as an example, a topographic and geological map drawn at a scale of 1:1000 clearly reveals the occurrence patterns of the orebody, which are controlled by northeast-trending fractures. This discovery provides a direct basis for planning the layout of development roadways, enabling more scientific and efficient mining operations. Without such an accurate topographic and geological map, the arrangement of development roadways might have been carried out blindly—leading not only to increased costs but also potentially compromising both mining efficiency and safety.

(II) Compilation Process and Key Technical Points

In areas covered by the Quaternary system, inferring the bedrock interface poses a significant challenge. To address this issue, a combined approach of trench exposure and geophysical inversion can be employed. Trenches should be spaced no more than 50 meters apart, allowing direct observation of the underlying bedrock conditions—but their coverage remains limited. Therefore, integrating geophysical inversion techniques, such as high-density electrical resistivity tomography, enables the use of geophysical methods to accurately estimate the location of the bedrock interface, ensuring that geological boundary errors are kept within 0.5 mm on the map. In one coal mining area, 3D seismic data were utilized to correct contour deviations in the coal seam floor traditionally controlled by drilling, resulting in a 12% improvement in reserve estimation accuracy. This clearly demonstrates that advanced data acquisition and processing methods play a crucial role in enhancing both the precision and reliability of topographic and geological maps.

The drawings should also include supplementary charts such as a comprehensive stratigraphic column, a typical geological profile, and a map showing the distribution of exploration projects. The comprehensive stratigraphic column is drawn to a scale of 1:500, clearly illustrating the layering of strata and the distinctive features of each layer. The typical geological profile is oriented perpendicular to the strike of the ore body, with the same scale as the main map, enabling a precise depiction of the ore body’s subsurface occurrence and the vertical variations in geological structures. Meanwhile, the exploration project distribution map marks boreholes, tunnel numbers, and sampling locations, providing detailed engineering information crucial for mine exploitation. In the case of a certain gold mine, the drawing was carefully designed using different color gradients to distinguish between the oxidation zone and the primary mineralized zone, vividly highlighting the spatial variation in the degree of ore oxidation. This method of graphical representation combined with strategic selection not only enhances the clarity and readability of the topographic and geological maps but also delivers more valuable insights to support efficient mine operations.

II. Hydrogeological Map: Visual Decoding of the Groundwater Environment

(1) Classification of Groundwater Types and Characterization of Key Parameters

In underground mining, the importance of hydrogeological maps is self-evident—they serve as the "water management records" for underground mines, providing crucial guidance for water control and prevention efforts throughout the mining process. At the heart of these maps lies a comprehensive and precise representation of groundwater systems, with the classification of groundwater types and the characterization of key parameters being fundamental and essential steps.

According to the GB/T 14538 standard, we can classify groundwater in mining areas into five basic types, each with its own unique formation mechanism and occurrence characteristics. Loose-rock pore water, depending on its burial conditions, can further be divided into two subtypes: phreatic water and confined water. This type of water is primarily stored in the pores of loose sediments such as sand and gravel, and its distribution is closely linked to topography and the grain size of the sediments. Clastic-rock fissure-pore water occurs in the fractures and pores of clastic rocks, with its water-bearing capacity influenced by the degree of fracture development and the cementation of the rock. Karstic water in carbonate rocks is a special type of groundwater formed in carbonate rock regions due to karstification processes; it features complex flow pathways, often giving rise to distinctive karst landforms like caves and underground rivers, and exhibits significant variability in water yield. Fractured bedrock water exists within fractures of various bedrock types, and its distribution and water-bearing capacity are closely tied to the lithology of the bedrock as well as the extent of tectonic fracturing. Finally, permafrost water forms in high-latitude or high-altitude regions due to the freezing of subsurface layers, making it a unique groundwater type whose dynamics are markedly affected by temperature fluctuations.

On the map, we need to clearly highlight three core elements that are essential for understanding the occurrence and movement patterns of groundwater. Among these, aquifer productivity is one key factor. We classify it into five levels—ranging from extremely abundant to extremely scarce—based on the yield of individual wells, visually represented through a gradient color scheme. For instance, in the hydrogeological map of a certain coal mine, porous aquifers are depicted using shades of blue to indicate varying degrees of productivity, while differences in water yield are precisely quantified via a color scale, making the information instantly comprehensible at a glance. Another critical element is the burial condition, which can be effectively illustrated by overlaying potentiometric surfaces (contours representing groundwater pressure) with piezometric lines. This combined display clearly reveals the depth of groundwater burial as well as the hydraulic head pressures. Typically, the contour interval for phreatic water levels is set at 0.5 meters, ensuring that even subtle changes in water levels are accurately reflected. Meanwhile, for confined aquifers, it’s crucial to mark the exact height of the hydraulic head, enabling precise monitoring of pressurized water conditions. Lastly, when dealing with permafrost-related water systems, it’s also necessary to indicate the depth of the base of the multi-year permafrost layer, with an accuracy requirement of ±0.3 meters. This precision is vital for guiding safe and efficient mining operations in cold-region environments. Finally, water quality characteristics cannot be overlooked. We use distinct symbols to denote mineralization levels across different zones, applying unique filling patterns accordingly: for example, slightly brackish water is shaded with dot patterns, while highly saline water is filled with cross-hatching. Additionally, areas where heavy metals exceed regulatory limits—such as regions with arsenic concentrations above 0.01 mg/L—are clearly marked. This detailed approach ensures that appropriate protective measures can be implemented during mining activities.

(II) Compilation Steps and Data Processing

III. Dual-Graphic Collaboration: Deep Integration from Drawing Preparation to Mining Practice

(1) Spatial Decision Support in Mining Design

In underground mine mining design, topographic and hydrogeological maps serve as a closely coordinated "think tank," providing comprehensive spatial decision-making support for extraction planning. Far from existing in isolation, these two maps are meticulously aligned in terms of their coordinate systems, scales, and layer divisions, seamlessly integrating into an organic whole.

In terms of the coordinate system, CGCS2000 is uniformly adopted, effectively establishing a unified "spatial coordinate language" for the mine. This ensures consistent geographic representation across the two maps, enabling accurate integration of data from different sources. Moreover, scale errors are controlled within ≤1%, a high-precision requirement that guarantees consistency in detailed features—whether it’s subtle terrain undulations or minor fluctuations in groundwater levels—all of which can be precisely depicted on both maps. Layering alignment is taken even further, with geological bodies, structures, aquifers, and other key elements systematically organized into standardized layers, making it easier to swiftly and accurately extract the information needed for spatial analysis.

In the roadway layout phase, the synergistic effect of these two maps is particularly crucial. By overlaying the topographic and geological map with the hydrogeological map, it’s as if miners have been given a pair of "透视 glasses," allowing them to clearly visualize the underground geological conditions and hydrological features. For instance, during the mining operation at a certain lead-zinc mine, this integrated analysis revealed that the originally planned route for the main transport tunnel ran through a steep terrain area (with slopes exceeding 30°), where a highly water-rich fault zone lay beneath (with an estimated inflow rate of over 500 tons per day). If construction had proceeded according to the original plan, not only would the project have faced significant construction challenges and high costs, but it would also have posed substantial safety risks. Therefore, based on the insights provided by the two maps, the mining team adjusted the tunnel route to a moderately water-bearing sandstone fracture zone, effectively avoiding the unfavorable topographic and hydrological conditions. As a result, the post-adjustment excavation saw a 40% reduction in water inflow, significantly easing both construction difficulties and costs while enhancing overall mining safety.

In water control and prevention design, these two types of maps play equally important roles. In karst-developed areas with low-lying terrain (where cave density is marked as greater than 5 caves per hectare), these regions often serve as conduits for groundwater convergence and flow, making them prone to sudden water bursts. By analyzing the confined water head contour lines on the hydrogeological map, combined with topographic information from the geological map, it becomes possible to precisely determine the optimal placement of advance exploration boreholes and the appropriate burial depth of water-stopping casing pipes. The spacing between advance boreholes should be no more than 10 meters—this density ensures effective detection of the underlying hydrogeological conditions, enabling timely identification of potential water-related hazards. Meanwhile, the burial depth of the water-stopping casing pipes must exceed the confined water level by at least 5 meters, guaranteeing that groundwater inflow into the mine tunnels can be effectively prevented during mining operations, thus safeguarding both operational safety and productivity.

(II) Dynamic Updates and Digital Transformation

As underground mining operations continue to advance, the geological conditions and hydrological features of the mine are also constantly evolving—much like a dynamic "underground world." Therefore, establishing a mechanism for dynamically updating mine drawings is absolutely essential. This mechanism ensures that these changes in the mine are promptly reflected, providing up-to-date information to support mining decision-making.

It is recommended to integrate newly revealed tunnel geological records, dewatering and drainage monitoring data, and geophysical exploration results on a quarterly basis. Tunnel geological records provide detailed documentation of the geological features exposed during mining operations, including rock properties and structural characteristics—information that helps us promptly track changes in the mine's geological conditions. Meanwhile, dewatering and drainage monitoring data offer insights into fluctuations in groundwater levels, with a required precision of ±2 cm. Such high-accuracy monitoring enables early detection of any abnormal changes in groundwater levels, providing vital early warnings for effective water management and prevention efforts. Additionally, geophysical exploration outcomes, such as 3D seismic surveys with a resolution of ≤5 meters, deliver even more comprehensive details about the underground geological structure, further enhancing our understanding of the mine's complex geology.

The application of digital tools provides robust support for the dynamic updating and management of drawings. The ArcGIS Mining module, for instance, is an exceptionally practical digital tool that enables parametric linkage between two types of maps. Through this module, various parameters from topographic-geological maps and hydrogeological maps—such as terrain elevation, stratum thickness, and groundwater levels—can be updated in real time and displayed in synchronized fashion. In a smart mine, a 3D geological-hydrological model built using BIM technology essentially creates a virtual "underground world" of the mine within the computer. This model can simulate in real time how the groundwater flow field evolves during mining operations. By analyzing different mining scenarios through simulation, it offers precise digital twin-based support for emergency flood-prevention plans, significantly enhancing the mine's ability to respond effectively to water-related hazards.

Conclusion: Solidify the foundation for safe and efficient mining operations with blueprint precision.

The compilation of mine-site topographic and hydrogeological maps essentially involves transforming complex geological information into quantifiable, actionable engineering language. Mining engineers must adhere to the principles of "data precision, standardized representation, and application-specific contextualization," meticulously capturing details—such as ensuring that the alignment error between topographic contour lines and geological boundaries remains below 0.3 mm—through a combination of field measurements and comprehensive indoor analysis. Moreover, by leveraging the synergy between these two types of maps, engineers can unlock valuable insights, like optimizing the layout of drainage systems through integrated analyses linking aquifer characteristics with orebody depth. With the growing adoption of drone-based mapping and advanced 3D modeling technologies, map compilation is evolving from a "two-dimensional plane" toward a "three-dimensional, dynamic framework." Yet, at the core of this transformation, steadfastly upholding fundamental mapping standards and fostering deeper, more collaborative professional thinking remain the critical technical safeguards that enable safe and efficient underground mining operations.