Post forest-fire hydrochemical behaviour of the Rimbaud catchment (Massif des Maures, France)

In August 1990, a forest fire devastated 84 % of the Rimbaud catchment area (1.46 km(2)). This catchment presents a substratum composed of gneiss. Its relief is sharp. Soils are skeletal. The forest fire destroyed a maquis (w ith treelike heather and arbustus) interspersed with cork oaks and maritime pines. The fire's effects on the chemical composition of the runoff have r emained light in terms of low flows. On the other hand, mineralization has greatly increased during flood, especially at the beginning of the 1990-91 water year. The paper reports on the observations conducted during four yea rs after the fire. Dissolved outputs and hydrochemical balances are compare d with results obtained on the same catchment before the forest fire, and o n the Boussicaut catchment (0.74 km(2)), which is very close by, but which was not burnt.