摘要：Recently, many remote-sensing datasets providing features ofindividual fire events from gridded global burned area products have beenreleased. Although very promising, these datasets still lack a quantitativeestimate of their accuracy with respect to historical ground-based firedatasets. Here, we compared three state-of-the-art remote-sensing datasets(RSDs; Fire Atlas, FRY, and GlobFire) with a harmonized ground-based dataset(GBD) compiled by fire agencies monitoring systems across the southwesternMediterranean Basin (2005–2015). We assessed the agreement between the RSDs andthe GBD with respect to both burned area (BA) and number of fires (NF). RSDs and theGBD were aggregated at monthly and 0.25∘ resolutions, consideringdifferent individual fire size thresholds ranging from 1 to 500 ha. Ourresults show that all datasets were highly correlated in terms of monthly BAand NF, but RSDs severely underestimated both (by 38 % and 96 %,respectively) when considering all fires > 1 ha. The agreementbetween RSDs and the GBD was strongly dependent on individual fire size andstrengthened when increasing the fire size threshold, with fires > 100 ha denoting a higher correlation and much lower error (BA10 %; NF 35 %). The agreement was also higher during the warm season(May to October) in particular across the regions with greater fire activitysuch as the northern Iberian Peninsula. The Fire Atlas displayed a slightlybetter performance with a lower relative error, although uncertainty in thegridded BA product largely outpaced uncertainties across the RSDs. Overall,our findings suggest a reasonable agreement between RSDs and the GBD for fireslarger than 100 ha, but care is needed when examining smaller fires atregional scales.
