Geochemical Behavior of Dissolved Organic Carbon under Baseflow Conditions at the Corbeira Stream Water,Spain

Geochemical processes related to dissolved organic carbon (DOC) under baseflow are studied in Corbeira Stream (northwestern Spain). The stream drains a catchment occupied by forest and agricultural fields. Dissolved organic carbon and other chemical parameters were analyzed. Seasonally, DOC values show a gradual rising background beginning in late spring to summer, finishing with major anomalies in the early to middle autumn. Suspended solids (SS) values exhibit a steady to falling background. The greatest DOC peaks seem be a function of rising temperatures and degradation of organic matter in wet soils. Divergent DOC and SS backgrounds in dry season and synchronicity between DOC-SS peaks associated with negative correlation of SS to pH in autumn seem be conspicuous geochemical signatures in perennial streams under temperate climates. The first one indicates the predominance of subsurface flows in streams, and the second one indicates the predominance of overland runoff.