Disaster mapping and assessment of Pakistan’s 2022 mega-flood based on multi-source data-driven approach

Climate change-induced mega-floods have become increasingly frequent worldwide. The rapid mapping and assessment of flood disasters pose urgent challenges for developing countries with poor data facilities or databases. In this study, the characteristics of the 2022 mega-flood in Pakistan were monitored and analyzed based on multi-resources data. The extent of inundation throughout Pakistan and its impact on farmlands, buildings, and roads were mapped using Synthetic Aperture Radar remote sensing data processing technology. The results showed that a 10-m resolution flooding map could be achieved using the Google Earth Engine platform in a timely manner with reasonable precision. A GIS-based bluespot model was used to evaluate the risk of dam-failure floods. The zone risk distribution map of the dam-failure flood was produced with five risk levels, which contribute to the safety of the key infrastructure for flooding control. The potential influencing factors of snow melting in northern Pakistan induced by heat waves and disasters was detected using Earth observations and long-record historical data. The study provides data-driven approach options for monitoring flood hazards over large areas in emergency using multi-available data sources, where in situ monitoring is difficult. This study not only provided direct data products and risk maps for mega-flooding control in Pakistan, but also proposed five aspects of flood prevention and control recommendations for this region and its neighborhood areas to cope with flood disasters effectively under worsening climate change conditions.