## 1 Introduction  
Coal resources constitute a significant portion of Chinese energy consumption mix [1], with reserves accounting for 91.2% of the country's major energy mineral reserves, according to a report from Ministry of Natural Resources of the People's Republic of China in 2023. Large-scale coal mining operations have led to progressive expending and deepening of goat areas. The overburden strata above goat areas experience gravitational collapse and fracturing, with deformation migrating upward through the rock mass until manifesting as surface subsidence [2]. Ground fractures frequently develop at the edges of subsidence zones, where vegetation root systems are damaged due to surface tension or compression, leading to subsequent vegetation degradation [34]. Consequently, proactive subsidence monitoring represents a critical mitigation measure against potential geohazards while simultaneously safeguarding the ecological environment [5; 6].  
However, traditional surface subsidence monitoring methods, such as leveling, electronic total station, and Global Navigation Satellite System (GNSS), face significant challenges in meeting the demands of large-scale mining monitoring due to their high costs, sparse observation coverage, and labor intensity [7; 8]. In contrast, Interferometric Synthetic Aperture Radar (InSAR) technology has emerged as a more advanced and effective approach for monitoring surface subsidence, with advantages relating to its wide range, low cost, and all-weather usability, which led to its rapid development and widespread adoption. Differential InSAR (D-InSAR), an extension of conventional InSAR technology [9; 10; 11], has been proven effective worldwide in measuring surface deformation and predicting mine-related seismic activity [12]. However, it still faces challenges such as poor temporal consistency and ineffectiveness for large-scale deformation monitoring [13; 14; 15]. The development of time series InSAR techniques [16], particularly SBAS-InSAR and persistent scatterer InSAR (PS-InSAR) [17; 18; 19], have effectively addressed the poor temporal resolution and coherence loss of D-InSAR. Both SBAS-InSAR and PS-InSAR have the advantage of anti-interference and high precision [20], while PS-InSAR imposes stringent stability requirements on monitoring targets. In comparison, SBAS-InSAR proves more suitable for monitoring surface subsidence in mining areas characterized by limited persistent scatterers [21; 22; 23; 24; 25].  
Ordos, a main prefecture-level city in the Inner Mongolia Autonomous Region, is one of the most important clusters of the modern coal chemical industry cluster in China. Ordos possesses substantial coal resources, with its reserves occupying about one-sixth of China's total coal reserves, which is estimated at more than one trillion tons. However, the region is facing severe ecological degradation and frequent geological disasters, which are exacerbated by coal mining operations [26; 27; 28; 29; 30]. Due to the erosional terrain of the Loess Plateau, traditional surface subsidence monitoring methods struggle to capture the extensive mine-induced subsidence in Ordos, which results in an incomplete and imprecise assessment of surface subsidence within the mining areas.  
Consequently, this study utilizes SBAS-InSAR techniques [31], along with European radar imaging satellite (Sentinel-1A) data from 2018 to 2023, to monitor surface subsidence in the Wanli mining area, which is a major coal mining area in Ordos. The study aims to investigate the characteristics and patterns of coal mining-induced subsidence in the erosional landforms of the Loess Plateau. The findings are intended to provide valuable reference data for analyzing surface subsidence patterns across diverse geological settings. In addition, this study provides reliable policymaking data to optimize cost efficiency and guide targeted monitoring in subsequent management work. Moreover, it offers methodological references for mining regions with similar geomorphological conditions.