Evaluation of surface runoff processes in gullies originated in conventional olive groves. A section to consider in territorial planning

Abstract

The hydrological response of one ephemeral gully during an “ordinary” rainfall event (with a return period of approximately 1 year) was assessed using a runoff simulation in an experimental catchment cultivated with olive groves in Puente Genil, Córdoba (Spain). 1000 l of water were pumped for 10 minutes in order to measure the total discharge, flow front velocity, sediment concentration and morphological changes of the transversal profile. The results showed high differences among runoff coefficients (of about 17%) under “dry” and “wet” conditions. The instantaneous sediment concentration values up to 40 g l-1. It was concluded that the ephemeral gullies in conventional olive groves are able to register high soil and water losses, particularly, under higher wet conditions. Thus, the importance to collect more information and pay attention to the soil erosion control measures against the concentrated runoff in agricultural land management plans have to be addressed.