Monitoring post-earthquake recovery and conducting impact factor analyses based on nighttime light data

This study analyzes post-earthquake recovery in seven Chinese regions impacted by the 2013 Lushan earthquake using nighttime light (NTL) data from 2012–2020 and advanced statistical methods, including loess decomposition and XGBoost-SHAP. The results indicate that by the end of 2020, all counties except Baoxing showed substantial recovery, with Qionglai achieving the highest pre-earthquake increase (91.62 %) in total nighttime light (TNL) brightness. The pre-earthquake TNL growth rates for Lushan, Mingshan, Pujiang, Tianquan, and Yucheng were 37.1 %, 42.5 %, 73.63 %, 40.57 %, and 38.01 %, respectively. Post-earthquake, all counties, except Mingshan, experienced a contraction in built-up areas, with reductions of 31.91 % (Baoxing), 14.34 % (Lushan), 58.65 % (Pujiang), 53.23 % (Tianquan), 47.67 % (Qionglai), and 6.34 % (Yucheng). Key socioeconomic factors—infrastructure improvements (particularly in transportation), steady growth in secondary industries (industrial and construction sectors), and the development of tertiary industries (including education and tourism)—played a significant positive role in post-earthquake recovery in these regions. This study provides valuable insights into the impacts of earthquakes on regional development and offers a basis for evaluating post-earthquake recovery progress and formulating effective disaster recovery strategies.