Research on the Construction of Applicable Models for Temporary Land Use in Open-Pit Coal Mining and Implementation Models for Land Reclamation in China

Abstract

China’s traditional approach to supplying land for mining operations hinders the sustainable use of land resources, resulting in extensive land degradation and idleness after mining activities conclude. Based on this, the competent national authorities have innovatively launched reforms to the temporary land supply model for open-pit coal mining operations. This study uses the Anjialing open-pit coal mine pilot project in Shanxi Province, China as a case example to construct a comprehensive lifecycle model for temporary mining land use in operational coal mines. It evaluates the land reclamation implementation at this mine and proposes a land management model for future pilot mines establishing new temporary mining sites. Research indicates that: (1) In pilot mining projects currently under construction, the larger the initial mining area, the lower the strip ratio and coal extraction rate, and the longer the overall duration of temporary land use. (2) Based on the overall land use cycle model for temporary mining sites, the land use cycle for the Anjialing open-pit coal mine is approximately 7 to 10 years, making it impossible to complete mining operations and return the land after reclamation within five years. (3) Based on historical image analysis using the GEE platform, by the end of 2020, the coal mine reclamation area barely reached the boundaries of the 2012 temporary land use plan. Consequently, the pilot project for temporary mining land use failed to pass the required acceptance inspection. Overall, the promotion of this new model not only upholds the critical mission of safeguarding national farmland and ensuring food security, but also holds significant implications for future resource extraction and sustainable land utilization.

1. Introduction

Land and mineral resources, as indispensable natural resources, provide the objective and fundamental material conditions for human survival and development. However, China’s available land resources contrast sharply with its current population size, and the conflict between population and land is particularly prominent. The large-scale and extensive exploitation of mineral resources inevitably leads to the continuous destruction of land resources and the ecological environment in mining areas, causing land damage, subsidence, and occupation [1,2,3]. According to 2022 remote sensing monitoring, China’s cumulative abandoned open-pit mining land area reached 827,347.35 hm², accounting for 0.86‰ of the national territory. It is primarily distributed in northern and northwestern China. Among these, mining activities have damaged and occupied 26,283.80 hm² of basic farmland, accounting for 3.18% of the total abandoned open-pit mining land nationwide. These areas are primarily distributed in Shandong, Henan, and Shanxi provinces [4,5]. In 2022, the total area of land reclamation for abandoned open-pit mines nationwide was approximately 320,000 hm², with a land reclamation rate of 38.68%, which is far below the reclamation levels of developed countries [6,7]. Therefore, land reclamation in mining areas and reforms to the mining land use system have attracted widespread attention from scholars both domestically and internationally.

Western countries have implemented a system where mineral resource ownership is separated from land ownership, and their approval systems and reclamation implementation mechanisms are more refined. The United States established the Surface Mining Reclamation Authority, which is specifically responsible for managing land reclamation efforts across all mining areas nationwide. It has developed a relatively comprehensive land reclamation system covering aspects such as mining land use and exit mechanisms. Germany implements extremely stringent enforcement standards throughout the entire mining and land reclamation process. For instance, during open-pit mining, topsoil and subsoil must be stacked in layers to ensure rapid restoration of land productivity during subsequent reclamation. In short, developed countries have established relatively well-developed mechanisms for the withdrawal of mining land and measures for the recycling of mining land [8,9,10,11,12,13,14,15,16,17]. Traditional mining land in China must undergo state expropriation to convert collectively-owned land into state-owned land, after which enterprises acquire land use rights through compensated use [18,19]. However, once mining operations conclude, mining enterprises have largely exhausted the land’s utility for extraction purposes. Coupled with delayed land reclamation efforts, this results in damaged land lying idle and barren for extended periods, ultimately becoming abandoned land [20]. Therefore, the current single land supply method for mining land has, to a certain extent, restricted the sustainable use of land [21].

Therefore, in 2005, the former Ministry of Land and Resources approved Pingguo bauxite mine in Guangxi as a pilot for reforming the temporary land supply system for open-pit mining. This innovative approach adopted a land rental model instead of expropriation, where land was leased from farmers in phases. The term of each temporary mining land use shall not exceed 2 years, and the implementation cycle for mining and land reclamation shall not exceed five years. After mining is completed and the land is reclaimed, it shall be returned to the farmers. This innovative land use model has enabled enterprises to reduce their land costs, farmers to receive greater economic compensation rather than losing their land, and local governments to alleviate the pressure of resettling farmers. It has also promoted the protection of arable land and the efficient and intensive use of land, representing a major breakthrough in the reform of the mining land use system [22,23,24]. In 2010, the former Ministry of Land and Resources expanded its pilot program for reforming mining land use methods, approving the temporary use of approximately 37,944.73 hm² of collectively owned farmland in 19 cities, including Ordos in Inner Mongolia and Shuozhou in Shanxi Province. However, most coal mining companies have a land reclamation rate of less than 50% upon expiration and a reclamation acceptance rate of less than 20%, which has increased the pressure on the government to resettle displaced farmers and highlighted the contradictions between the government, companies, and farmers [25,26,27]. This calls for reflection on why the bauxite mine in Pingguo was a success, while the open-pit mine pilot project repeatedly failed. Therefore, only by clarifying the applicable conditions for temporary land use in open-pit mining [28,29] can we avoid blind applications by various mining companies and ensure the effective promotion of the temporary land use system for mining.

Based on the above background, this study theoretically examines the applicability conditions and target entities for temporary land use in open-pit mining. Using the Pingshuo Open-Pit Mine in Shanxi Province as a case study, it constructs a comprehensive lifecycle model for temporary mining land use in operational and under-construction mines. Based on historical imagery analysis from 2011 to 2020 using the Google Earth Engine (GEE) platform, we examined changes in the implementation of coal mine land reclamation. Finally, a land reclamation model for temporary mining land use at newly established pilot mines is proposed to provide theoretical support for future pilot applications for temporary mining land use.

2. Materials and Methods

2.1. Study Area

The Pingshuo open-pit mine (112°23′46.249″ E, 39°28′18.580″ N) is located in Shuozhou City in northern Shanxi Province. It is a typical large-scale open-pit coal mine in China, consisting of three major open-pit coal mines—Antaibao, Anjialing, Dong and an underground coal mine (Figure 1). The mining area is 21 km long from north to south and 22 km wide from east to west, covering an area of approximately 400 km². It has geological reserves of approximately 12.75 billion tons and is one of China’s important energy bases. The study area has a typical temperate arid and semi-arid continental monsoon climate with relatively low vegetation coverage. The region has suffered from soil erosion for many years and has a fragile ecological environment.

Anjialing open-pit mine is the largest open-pit coal mine in the Pingshuo mining area. In October 2011, it became a pilot project for mining land use reform. The mine field is 7842 m wide from east to west and 6556 m long from north to south, with a total area of 28.88 km². The main coal seams being mined are Seams 4, 9, and 11, with average heights of 10 m, 12.5 m, and 4 m, respectively. The main area of this study is located in the initial mining area of the Anjialing open-pit mine, with mining progressing from west to east. The geological structure within the mining area is divided into three regions: the reverse fault zone, the anticline zone, and the post-anticline zone. The overall average stripping ratio is 4.31 m³/t, with an annual coal mining advance length of 320 m (Data sourced from the Anjialing mining report) (Figure 2).

2.2. Data

This study utilizes historical imagery data primarily sourced from high-resolution imagery integrated on the GEE platform (Sentinel-2, Landsat 8, etc.). A total of 10 remote sensing images of the Pingshuo mining area from 2011 to 2020 were obtained. Perform batch image correction, mosaicking, and other preprocessing tasks on the GEE platform. Using GEE’s image annotation tools and geographic vector editing functions, we extracted the mining and land reclamation implementation areas in the mining district through visual interpretation and analyzed the changes in land reclamation implementation in the temporary mining land of Anjialing coal mine from 2011 to 2020.

2.3. Model Construction for Temporary Land Use in Mining Production

Most pilot sites for temporary land use in open-pit mining are active mining operations that had already formed excavation areas of considerable scale prior to applying for the pilot program (Figure 3: Area A). The distance between the rear end of the excavation area and the front edge of the temporary land use zone is L, while the length of the already mined area is L₀. Currently, for the reclamation of open-pit coal mines, the competent national authorities require that after mining operations conclude, the waste rock dumps must be backfilled to restore the mined areas. Even if the volume of waste rock cannot fully cover the mined areas, maximum reclamation must still be ensured. And use the “horizontal mining and internal disposal” process to minimize the negative impact of external disposal and accumulation on the environment. The areas subject to phased approval for temporary land use are typically located along the coal mining advance direction (B1, B2, B3, and B4), where topsoil is stripped and piled separately, while other solid waste is disposed of and backfilled along the rear of the mining area. Once part of the internal disposal reaches the design elevation, reclamation is carried out. After coal mining has progressed to the temporary land use area for Phase I, an application for temporary land use area for Phase II shall be submitted, and so on. According to this “extraction-reclamation-restoration” process, after the end of the first phase of land use (B1), the enterprise shall reclaim an area of A + B1 and return the reclaimed land after inspection to achieve the purpose of temporary use.

In the preliminary stage of model construction, considering that the width of the temporary site is identical to that of the mining area, and to simplify the model, the length of the mining area (L) and the length of the temporary site (L_i) were adopted as the fundamental parameters for model development.

2.3.1. Constructing a Model for the Length of the Waste Rock Disposal Area at the Rear End of the Mining Area

Typically, open-pit mining requires the removal of surface rock in order to extract the ore. The ratio of the amount of rock stripped to the amount of ore extracted is called the strip ratio. Among these, the average strip ratio serves as a crucial comprehensive parameter in mining design and stripping operations, directly impacting the annual advance rate of coal mining. Therefore, if the amount of rock stripped during mining is strictly controlled and promptly transported to the rear of the mining area (“Mine and dump soil simultaneously”), the length of the theoretical transport area can be expressed by the following formula:

$$L_d=tv{\displaystyle \frac{r_s}{r_s+1}}(v=f(C_r,B_d,C_s,G_l\left)\right)$$

(1)

In Formula (1), L_d is the length of the waste rock area, t is the number of years of mining, v is the annual coal mining advance rate [30,31] (where the coal mining advance rate is related to coal reserves C_r, ore body burial depth B_d, number of coal seams C_s, geological rock properties G_l, etc.), and r_s is the average stripping ratio.

2.3.2. Establishing a Mining Cycle Model for the Exploitation and Reclamation of Temporary Mining Sites

Currently, most enterprises applying for temporary mining land use pilot programs are active mining operations, and the land use period must not exceed 5 years. Therefore, according to Formula (1), the usage cycle of temporary land use for mining operations can be expressed by the following formula:

$$t_m={\displaystyle \frac{{L-L}_0+{\sum }_{i=1}^n{L}_i}{v}}$$

(2)

$$t_r=(L+{\sum }_{i=1}^n{L}_i-v\beta )/\left(v{\displaystyle \frac{r_s}{r_s+1}}\right)$$

(3)

In Equations (2) and (3), t_m represents the remaining mining years; t_r represents the number of years required for reclamation after mining ceases; L represents the length of the mining area; L₀ represents the length of the already mined area; L_i represents the length of each temporary land use period; β represents the ideal simultaneous mining and reclamation rate during the mining process [32,33] (calculated based on the average stripping ratio as 0.81).

2.3.3. Establishing a Model for the Overall Usage Cycle of Temporary Land Use for Mining

According to formulas (2) and (3), the total duration (T) of the temporary land use of the pilot unit and the length (L) of the mining area should satisfy the following relationship:

$$T=t_m+t_r=\left({\displaystyle \frac{{L-L}_0+{\sum }_{i=1}^n{L}_i}{v}}\right)+(L+{\sum }_{i=1}^n{L}_i-v\beta )/\left(v{\displaystyle \frac{r_s}{r_s+1}}\right)\left(T\le 5\right)$$

(4)

As can be seen from Formula (4), the total duration of land use for pilot enterprises applying for temporary mining land is related to parameters such as the length of the mining area (L) prior to the application, the annual advance rate of coal mining (v), and the average stripping ratio (r_s).

3. Results

3.1. Simulation Analysis of Temporary Land Use for Mining at Anjialing Open-Pit Mine

3.1.1. Land Use Simulation

In early 2011, the former Ministry of Land and Resources approved the 2011–2015 temporary land use plan for mining at Anjialing mine, with a total area of 470.91 hm². The horizontal lengths of the temporary land use areas in 2011, 2012, 2013, 2014, and 2015 were 360.88 m, 458.38 m, 449.22 m, 447.09 m, and 451.69 m, respectively (

Table 1. Table of the number of years of use of temporary mining land at Anjialing open-pit coal mine during different periods.

Approval Year	Area/hm2	L	L0	Li	v	rs	β	tm	tr	T
2011	85.75	1431.69	1216.53	360.88	320	4.31	0.81	1.80	5.90	7.70
2012	97.46	1431.69	1216.53	458.38	320	4.31	0.81	3.23	6.28	9.51
2013	96.58	1431.69	1216.53	449.22	320	4.31	0.81	4.64	6.24	10.88
2014	95.15	1431.69	1216.53	447.09	320	4.31	0.81	6.03	6.23	12.27
2015	95.97	1431.69	1216.53	451.69	320	4.31	0.81	7.45	6.25	13.70

In Table 1, L represents the length of the mining area. L₀ represents the length of the mined area. Li represents the length of each temporary land parcel. v represents the coal mining rate. r_s represents the average stripping ratio. β represents the reclamation rate. tm represents the remaining years of mining. tr represents the number of years required for reclamation after mining operations cease. T represents the total duration of temporary land use.

). At this point, the Anjialing open-pit mining area had been mined to a length of 1216.53 m. In accordance with national requirements for open-pit coal mine reclamation and the temporary land use and reclamation plan, the mine must not only reclaim the areas designated for temporary use but also simultaneously reclaim the areas that have already been mined. Therefore, waste generated during mining in Area B1 should first be backfilled into previously mined areas. The waste rock disposal area on the western side of the mining area had not yet reached the designed elevation, and this section of the area could still accommodate partial waste rock disposal. Therefore, the boundary of the western waste rock disposal area was designated as the theoretical waste rock disposal boundary for early 2011. According to Formula (1), the annual mining advance rate (320 m) and average stripping ratio (4.31 m³/t) are used to calculate the waste rock dumping length as 259.74 m. Based on DEM data and the ArcGIS 3D Analyst analysis module, a simulation diagram of the “mining-dumping” process for the Anjialing open-pit mine from 2012 to 2025 is generated (Figure 4).

According to the simulation process diagram, under the condition that Anjialing Mine fully implements “simultaneous mining and waste disposal” without considering other influencing factors (such as project delays, work stoppages, etc.), the earliest time for waste disposal to reach the western boundary of the 2011 mining temporary land use area is approximately 2016. The complete removal of spoil to the temporary use area designated for 2011 is expected to be completed around 2018 (Table 1). Once the spoil has been removed to the boundary and meets the design elevation, reclamation work (such as vegetation restoration and soil reconstruction) will begin. To achieve a usable standard, the land will require approximately three years of biochemical engineering, including fertilization. Therefore, the earliest date for the reclamation and return of temporary mining land in 2011 will be 2021, which is about five years later than the specified deadline of 2016. Furthermore, as coal mining continues to advance eastward, the deadline for the reclamation of temporary land use from 2012 to 2015 will also be delayed. According to calculations, the earliest date for dumping soil to the eastern boundary of the temporary land use area in 2015 is 2025. If the reclamation acceptance standards are to be met, the time required for the complete return of all temporary land use areas is approximately 2028.

3.1.2. Analysis of the Suitability of Temporary Land Use for Mining

According to the Anjialing coal mine temporary land use plan for mining, in 2011, as coal mining operations continued to advance eastward, the solid waste generated during the process was disposed of behind the mining site, thereby maximizing the efficiency of simultaneous mining and waste disposal. When the mining area exceeds the boundary of the 2011 temporary land use (B1), apply for the 2012 land use plan (B2), and continue mining, dredging, and restoration during the mining process until mining advances to the boundary of the 2015 temporary land use. At this point, mining within the 2011–2015 temporary land use area has been completed, and mining continues to advance eastward. According to the five-year land use period, the reclamation of land from 2011 should be completed by the end of 2016. Based on this schedule, the reclamation and return of land from 2012 will be completed by the end of 2017. By the end of 2020, all land from 2015 and earlier will be reclaimed, returned, and handed back to farmers for use.

Analysis of the successful land reform experience at the Pingguo Bauxite Mine in Guangxi reveals that the ore body is shallowly buried with a thin deposit averaging approximately 4.52 m in thickness. The overburden requiring stripping is only about 0.5 m thick, significantly thinner than other bauxite deposits in China. With a mining cycle of 1–2 years and reclamation taking 2–3 years, these resource conditions make open-pit mining the most suitable approach. The newly applied pilot mining areas feature deeply buried ore bodies and numerous coal seams, which will result in high mining technical difficulty, a large stripping ratio, and the need to transport substantial overburden, making subsequent land reclamation challenging. Additionally, complex geological structures will render mining workfaces highly unstable, prolonging the mining timeline. For open-pit mining, the greater the hardness of geological rock formations, the more difficult they are to break and extract, thereby impacting the overall land utilization cycle.

3.2. GEE-Based Assessment and Validation Analysis of Land Reclamation

To validate the model and evaluate the actual “mining-dumping-reclamation” process at Anjialing open-pit mine, this study conducted remote sensing image analysis of temporary land use and waste rock reclamation at Anjialing open-pit mine from 2011 to 2021 based on historical image changes on the Google Earth Engine (GEE) platform.

According to remote sensing data from December 2012 (Figure 5a). Over the past two years, the stripping area of the mine’s temporary land use has approached the land approval boundary established in 2014. Mining operations have progressed rapidly, with the coal mining working line at the pit bottom advancing 704.46 m. Land stripping for 2014 was completed in October 2013, with the bottom working line advancing approximately 305.20 m. The year 2014 had already crossed the land boundary of 2015, yet the newly added waste rock volume only met the theoretical waste rock area for 2013. The mining area for 2016 entirely exceeded the land boundary of 2015. In accordance with the requirement to return land within five years, the temporary land use from 2011 should have been fully reclaimed and returned in full. However, remote sensing imagery from 2016 (Figure 5e) indicates that the mine had not reclaimed the temporary land use area up to its 2011 boundary. As mining operations accelerated from 2016 to 2021, the progress of land reclamation and return remained far from satisfactory. In August 2020 (Figure 5i), Anjialing coal mine gradually began reclamation of land occupied in 2011. By the end of 2020 (Figure 5i), temporary land use from 2015 should have been returned as required. However, the reclaimed area barely reached the boundary of the 2012 temporary land use. Therefore, the pilot program for temporary mining land use applied for by Anjialing coal mine between 2011 and 2015 did not pass the final inspection.

As of December 2021, the initial mining area of the Anjialing open-pit mine has been largely depleted. However, based on the current reclamation progress, it will only be possible to restore the temporary land use area from 2013. The completion of mining in the initial area also signifies a shortage of soil resources for reclamation (Figure 5i). Due to the excessive size of the initial mining area, the overburden removed during coal mining only sufficed to cover the pits left behind from the initial mining, resulting in the temporary use areas from 2014 and 2015, as well as the large open-pit mine on the east side, being difficult to reclaim in the short term.

Meanwhile, none of the other pilot mines in the Pingshuo mining area have met the standards for land reclamation and restoration. By the end of 2016, the three super-large open-pit mines in the Pingshuo Mining Area should complete the land reclamation of 289.91 hm² (including 219.80 hm² of agricultural land) as approved in 2011.

According to the survey, the area eligible for reclamation in 2011 was 79.01 hm² (among them, the Antai open-pit mine covers an area of 41.69 hm², the Anjialing open-pit mine covers an area of 28.66 hm², and the Dong open-pit mine covers an area of 8.66 hm²), accounting for 27.25% of the total approved area (289.91 hm²) (Figure 6).

3.3. Land Reclamation Model for Temporary Mining Land Use at Newly Established Pilot Mines

For newly applied pilot mines for temporary mining land use, the implementation of land use should fully ensure the coordination between mining and reclamation. During the mining phase, topsoil should be stripped and stored appropriately to facilitate the restoration of the soil for subsequent reclamation. New mines will form temporary external waste dumps during the initial stages of mining, and internal disposal can only be carried out after mining has progressed a certain distance. Therefore, the area of the waste rock dump at the beginning of mining should also be included in the temporary land use area. However, according to current domestic environmental protection regulations, landfills generated by mining after land supply must be reclaimed. If this approach is followed, each phase of the waste rock dump remediation will need to be backfilled into the mining pit two years later, and each phase of waste rock dump remediation will need to be carried out, resulting in a waste of reclamation funds.

Therefore, this study proposes a “mining-dumping-reclamation” process for newly established pilot enterprises. The primary requirements include: During the initial land supply phase, spoil disposal should be conducted at nearby locations (temporary spoil disposal areas should also be managed as temporary land use). Full consideration must be given to the hydrological and geological conditions of the disposal area, with precise calculations of the angle of repose for the deposited material to prevent landslides. Simultaneously, the height of the spoil, compaction density, platform width, and bench slope angle should be scientifically determined to ensure the stability of the spoil disposal site. After the first phase of land supply is completed, the spoil tip will not be backfilled immediately. Once the second phase of land supply begins, the stripped rock and soil, along with waste materials, will be backfilled into the bottom of the first-phase excavation pit. Once the backfill reaches the specified elevation, the stripped topsoil will be used to cover the area. Similarly, the rock and soil stripped in the third phase and the waste materials were backfilled into the second phase pit, and so on. After final mining is completed, the remaining mine pits will be backfilled with spoil from the first phase (Figure 7). In cases where the filling material is insufficient, Chinese scholars have utilized Yellow River sediment as a filling material for land reclamation, developing a layered soil reconstruction method using Yellow River sediment. They have also developed adapted technologies for reconstructing rock and soil layers in open-pit coal mines [34,35,36,37,38]. This method of simultaneous mining and reclamation can effectively alleviate the pressure on enterprises to reclaim land and reduce the investment of reclamation funds, thereby effectively promoting the effective implementation of the temporary land use system.

Currently, the approval process for temporary mining land use is relatively cumbersome, with approval times sometimes exceeding several months, significantly impacting the efficiency of implementing temporary land use. Therefore, national and local natural resources management departments should promptly issue corresponding management documents to streamline temporary land use approval procedures and shorten approval times. Enterprises must embrace innovative concepts across multiple dimensions—including mindset, systems, management, and technology—resolutely abandoning outdated and rigid traditional mining approaches. They should reinforce the principle of “destruction source and mining process control,” adhere to the “mine while rehabilitating” code of conduct during extraction, and strictly follow mining stripping plans and waste rock disposal plans. Concurrently, natural resources management departments at all levels should implement tiered supervision mechanisms, mandating that mining enterprises report their annual temporary land use status and land reclamation progress to county-level natural resources departments by specified deadlines.

4. Discussion

The traditional model of land acquisition for mining operations will continue to result in larger-scale loss of land for farmers. Unlike permanent urban construction land, mining land use is characterized by temporary occupation over a specific period. Therefore, the most appropriate approach for mining land is to adopt a short-term land use rights acquisition method. Under the traditional land acquisition and transfer approach, after mining operations conclude, enterprises reclaim the land but retain no usage rights. Consequently, the reclaimed land remains uncultivated, leading to substantial land idleness. Therefore, encouraging the continued adoption of a temporary land use model better safeguards the interests of landowners. However, due to the highly disruptive nature of large-scale open-pit mines and their extensive impact on land, combined with an analysis of the coal seam burial, mining processes, and waste disposal processes of the three open-pit mines in the Pingshuo mining area, the land use cycle for mining enterprises should include stripping, mining, waste disposal, reclamation, and maintenance periods. Typically, the stripping and mining cycles generally require 4–6 years, and the reclamation cycle requires 3–5 years, with the entire cycle lasting approximately 7 to 11 years. Therefore, for the Pingshuo mining area and similar super-large mines, due to the influence of various factors such as resource endowment conditions, mining technology, and market conditions, it is unlikely that the land will be returned within five years from the start of mining to the completion of reclamation. In the future, in order to avoid blind applications from open-pit mining companies, the applicable conditions for temporary land use applications should be clearly defined to identify mining companies that are suitable for pilot programs. For pilot projects currently undergoing mining operations, strict adherence to mining, waste rock disposal, and reclamation plans is required. Where mining pits left after operations conclude cannot be backfilled and reclaimed for agricultural use, the situation should be promptly reported to the competent authorities to explore alternative reclamation approaches. Competent authorities should also continue refining relevant systems for the use of temporary land and implement comprehensive standardized management.

This study constructed a comprehensive lifecycle model for mining temporary land use based on parameters such as the strip ratio, mining field length, coal extraction advancement rate, reclamation rate, and temporary land use length. It effectively achieved quantitative description and lifecycle prediction of the spatiotemporal process of land occupation, but also has certain limitations. This model adheres to static assumptions and highly simplified principles, aiming to support the bold attempts and preliminary explorations in China’s current reform of temporary land use for mining. Treating parameters such as the strip ratio and coal mining advance rate as constant values in the model overlooks dynamic uncertainties like geological variations in mining areas, equipment failures, and market fluctuations, inevitably leading to discrepancies between the forecast results and actual outcomes. Second, the model structure is relatively idealized, making it difficult to simulate the cumulative effects of complex mining layouts—such as alternating multiple working faces and successive mining areas—on land use timing. It also fails to reflect the substantive impacts of different reclamation techniques, soil reconstruction difficulty, seasonal vegetation recovery, and acceptance policies on the land return cycle. Finally, the models predominantly focus on the primary “mining-reclamation” process, failing to adequately account for non-technical external delays such as temporary land use approvals, community coordination, and extreme weather events. Our team will continue to refine this model, fully accounting for the dynamic and random nature of coal mining’s surface impacts as well as external environmental factors. We aim to establish a more comprehensive and resilient integrated “technology-management” assessment system, thereby providing more scientific decision support for refined management of mining land resources and sustainable land development.

5. Conclusions

This study uses a typical large-scale open-pit coal mine in China as an example to simulate the “mining-dumping-reclamation” process during the nearly 10 years of land use in open-pit coal mines. A comprehensive model of the overall usage cycle for temporary mining land in coal mines under construction has been established. Based on GEE, a validation analysis of the land reclamation implementation status of the coal mine was conducted, clarifying the applicable conditions for applying for temporary mining land and proposing a land reclamation implementation model for future pilot mines under construction. The main conclusions are as follows:

(1) The overall usage cycle of temporary land for mining in mines under construction is closely related to the geological conditions of the mining site. The larger the initial excavation area, the smaller the stripping ratio and coal mining speed, and the longer the overall usage cycle of the land. (2) Based on the overall usage cycle model for temporary mining land, the Anjialing open-pit coal mine cannot complete mining and reclamation within five years. Its usage cycle is approximately 7–10 years. (3) Based on historical image changes from 2011 to 2020 analyzed using the Google Earth Engine (GEE) platform, by the end of 2020, the coal mine reclamation area barely reached the boundaries of the 2012 temporary land use plan, and the application for a pilot project for temporary mining land use was not successfully approved.

This study has established a preliminary applicable model for temporary mining land use. In the future, the model parameters will continue to be gradually refined and improved to provide theoretical support for future pilot applications for temporary mining land use. Overall, new pilot enterprises should try to pick mines with smaller mining areas and shorter mining land use cycles, and gradually roll out new land use models. This will help protect the country’s farmland and food security strategy, and will also be important for future resource extraction and land use.