Monitoring hydrology and sediment transport in a mediterranean agricultural catchment (Mallorca, Spain)

Abstract

[eng] A study of hydrological and sediment transport was conducted in Can Revull, a Mediterranean agricultural small catchment (1.03 km-) mostly under-drained. Mean annual precipitation and discharge are 517 mm and 4.11 S-l respectively. On the annual and seasonal time scales, PET generates a succession of three hydrological periods and plays an important role in baseflow dynamics. The annual average SSC was 17.3mg 1-1, with a maximum of 2,270 mg 1-1.Suspended sediment yields were an order of magnitude lower than other Mediterranean catchments because the historical use of soil conservation practices. At event-scale, multiple regression models identify the significant effect of water-storage capacity and under-drainage conditions over quickflow response, a fact made evident by the high annual runoff rates (''25%). However, rainfall intensity variables negatively correct the runoff behaviour as the Hortonian response is limited to dry seasons when baseflow is not present and discharge values therefore tend to be lower. Nevertheless, rainfall intensity is the most significant variable in sediment supply.