## 2 Article Inclusion Criteria and Description  
The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) workflow was utilized in this paper to conduct a systematic literature review on landslide monitoring and susceptibility mapping [39]. We used the advanced search query builder to gather literature from the WoS core collection database (Formula (1), where \(T\!I\) indicates title).  
\[(T\!I=(\textit{Landslide}))\;AND\;(T\!I=(\textit{Remote Sensing})\;OR\;T \!I=(\textit{Satellite})\;OR\;T\!I=(\textit{InSAR})\;OR\;T\!I\\ =(\textit{Earth Observation}))\;AND\;(T\!I=(\textit{Monitor})\;OR\;T\!I=( \textit{Monitoring})\;OR\;T\!I\\ =(\textit{Prediction})\;OR\;T\!I=(\textit{Susceptibility})) \tag{1}\]  
The application of InSAR in landslide research typically encompasses a wide range of topics, such as landslide detection and inventory, monitoring, susceptibility mapping, risk and hazard assessment, early warning systems, and SAR hardware advancements specifically designed for landslide studies. However, this review primarily focuses on landslide monitoring and susceptibility mapping, which significantly narrows the scope presented in Figure 1. In addition, InSAR technology can be deployed across various platforms, including ground-based InSAR (GB-InSAR), unmanned aerial vehicles (UAVs)-based InSAR, and satellite-based InSAR. This review specifically examines the application of satellite-based InSAR, further refining the selection. Nevertheless, we have also included articles utilizing other spaceborne remote sensing technologies, such as optical remote sensing, within our querying results. This selection is justified for two reasons: Firstly, examining studies utilizing spaceborne remotely sensed data allows us to assess the proportion and trends of InSAR applications within the broader context. This approach not only confirms the current standing of InSAR but also reveals its future potential and directions for development. Secondly, landslide research is an interdisciplinary field where different spaceborne remote sensing technologies often complement each other. Especially for LSM, optical remote sensing provides high-resolution surface imagery to calculate diverse factors, while InSAR excels in measuring landslide deformation.  
As of 15 March 2024, the initial search resulted in 255 articles, which were then refined using specific criteria. Only articles published in English between 1 January 2013, and 31 December 2023, were considered. We excluded studies that solely relied on field measurements or ground-based techniques (such as GB-InSAR) but included those utilizing other spaceborne remote sensing imagery. Additionally, duplicate and inaccessible articles, as well as some conference papers lacking sufficient detail for proper evaluation, were also excluded. The final literature collection for statistical analysis comprises 131 articles, including 80 research articles utilizing InSAR, 47 research articles simply using other spaceborne remote sensing, and 4 review articles (Figure 2).  
Regarding the publication trends of the selected articles, the past decade has seen a marked increase (Figure 3), reflecting growing interest and advancements in relevant fields. The total number of publications reached 34 in 2023. Notably, the proportion of studies employing InSAR has also risen, indicating its increasing prominence. By 2023, InSAR-based publications constituted a substantial portion of the research, highlighting its critical role in landslide studies. This exponential growth indicates an expanding body of knowledge and an escalating interest in utilizing InSAR for landslide research, emphasizing the critical need to compile and review the burgeoning literature in this area.  
Figure 2: Diagram of PRISMA approach framework for this systematic review. (Software: Microsoft Visio 2021 Professional).