Wildfire Suppression Difficulty Index 90th Percentile 2026 (Image Service)

Wildfire Suppression Difficulty Index (SDI) 97th Percentile is a rating of relative difficulty in performing fire control work under regionally appropriate fuel moisture and 20 mph uphill winds (@ 20 ft); Wildfire Suppression Difficulty Index (SDI) 90th Percentile is a rating of relative difficulty in performing fire control work under regionally appropriate fuel moisture and 15 mph uphill winds (@ 20 ft). Wildfire Suppression Difficulty Index (SDI) 80th Percentile is a rating of relative difficulty in performing fire control work under regionally appropriate fuel moisture and 10 mph uphill winds (@ 20 ft). SDI factors in topography, fuels, expected fire behavior under prevailing conditions, fireline production rates in various fuel types with and without heavy equipment, and access via roads, trails, or cross-country travel. SDI does not account for standing snags or other overhead hazards to firefighters, so it is not a firefighter hazard map. It is only showing in relative terms where it is harder or easier to perform suppression work.野火抑制难度指数（Wildfire Suppression Difficulty Index，SDI）第97百分位，是在区域适宜的可燃物含水率及20英尺高度下20英里每小时上坡风速（@20 ft）的条件下，用于评估灭火作业相对难度的指标；野火抑制难度指数（SDI）第90百分位，是在区域适宜的可燃物含水率及20英尺高度下15英里每小时上坡风速（@20 ft）的条件下，用于评估灭火作业相对难度的指标；野火抑制难度指数（SDI）第80百分位，是在区域适宜的可燃物含水率及20英尺高度下10英里每小时上坡风速（@20 ft）的条件下，用于评估灭火作业相对难度的指标。SDI综合考量地形、可燃物特性、当前条件下的预期火行为、不同可燃物类型下使用与不使用重型设备时的防火线构筑速率，以及通过道路、步道或越野通行的作业可达性。该指标未将立枯木或其他对消防员的高空隐患纳入考量范畴，因此并非消防员安全隐患地图，仅用于相对展示灭火作业难度更高或更低的区域。