Dry Lightning Contributing to Wildfires in the Zagros Forested Area: A Meteorological and Environmental Analysis of Extreme Events in June ۲۰۱۹ and May ۲۰۲۰

Wildfires in forested and pasture areas of Iran have increased in recent years, raising concerns about their ignition sources and environmental drivers. Among natural causes, lightning—particularly dry lightning—plays a significant role in initiating wildfires under specific meteorological conditions. This study aims to analyze the contribution of dry lightning to major wildfire events in Iran’s Zagros region during May ۲۰۲۰ and June ۲۰۱۹. To achieve this, we utilized a combination of satellite-based fire data from FIRMS and lightning data from the Earth Networks Total Lightning Network (ENTLN). In addition, meteorological datasets and reanalysis models were employed to assess drought conditions and fire-conducive weather patterns. Key indices such as the Fire Weather Index (FWI), Fire Danger Index (FDI), Burned Area Index (BI), Keetch–Byram Drought Index (KBDI), and the Standardized Precipitation Evaporation Index (SPEI) were applied. Burn severity was evaluated using Landsat-۸ and Sentinel-۲ imagery. Our results reveal a strong correlation between wildfire activity and lightning occurrences, particularly in areas with dry vegetation, elevated temperatures, and minimal precipitation. Quantitative validation during two major fire events—June ۲۰۱۹ and May ۲۰۲۰—confirms that wildfires were most intense on days when dry lightning coincided with elevated Fire Weather Index (FWI) values. For instance, on June ۶ and ۷, ۲۰۱۹, ۴۳۳۲ and ۴۸۳۳ dry lightning strikes were recorded, with FWI values of ۳۳.۸ and ۳۹.۴, and over ۹۰۰ high-confidence fire detections observed each day. Similarly, May ۲۰ and ۲۱, ۲۰۲۰ exhibited peaks in all three factors, with up to ۵۷۷۳ lightning strikes and FWI values exceeding ۲۴. These findings substantiate the synergistic role of dry lightning and fuel flammability in wildfire ignition and highlight the importance of multi-variable monitoring for fire risk assessment. This study highlights the importance of integrating satellite data, lightning observations, and fire indices for wildfire risk assessment. Ultimately, this research provides valuable insight into the mechanisms of dry lightning-induced wildfires and contributes to developing early warning strategies and adaptation measures under changing climate conditions.

کلیدواژه ها:

Fire Indices ، Firms ، Forest wildfire ، Lightning ، Zagros Mountains