Abstract
A deeper knowledge of the hydrological response of semi-arid Mediterranean watersheds would be useful in the prediction of runoff production for assessing flood risks and planning flood mitigation works. This study was conducted to identify the runoff generation mechanisms and their controlling factors at the hillslope scale in a Mediterranean semi-arid watershed. Four zero-order microcatchments were selected to measure rainfall and runoff for a three-year period. Two groups of soil were differentiated with respect to the hydrological response. The fine textured, poorly permeable soils of low organic carbon content had a greater runoff coefficient (9%) and lower runoff threshold (3·6 mm) than more permeable, coarser textured soils of medium organic carbon content (<3%, and 8 mm, respectively). The influence of rainfall characteristics on the hydrological response was different. Rain intensity was the major rainfall parameter controlling the runoff response in the microcatchments on fine textured, low infiltrability soils with a poor plant cover, while total rainfall was more closely correlated with runoff in coarser textured, highly permeable soils with a denser plant cover. It can be concluded that there are two runoff generation mechanisms: (i) an infiltration-excess overland flow in the more degraded areas with low organic carbon content (<0·5%) and low infiltrability (>5 mm h−1); and (ii) a saturation-excess overland flow in the less degraded areas with a high organic carbon content (>2%), high infiltrability (>8 mm h−1) and covered by a dense plant cover (>50%). © 1998 John Wiley & Sons, Ltd.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.