The influence of geomorphological position and vegetation cover on the erosional and hydrological processes on a Mediterranean hillslope

✍ Scribed by A. Cerdà

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 258 KB
• Volume: 12
• Category: Article
• ISSN: 0885-6087
• DOI: 10.1002/(sici)1099-1085(19980330)12:4<661::aid-hyp607>3.0.co;2-7

✦ Synopsis

Soil erosion and runo rates are assumed to be highly dependent on slope position. However, little knowledge exists about the hydrogeomorphological processes at the pedon scale that support this idea. In order to assess the hydrological and erosional behaviour of soils at dierent slope positions, simulated rainfall experiments (55 mm was applied during one hour) were carried out on a south-facing slope with underlying limestone in south-east Spain.

In the mean terms, the erosion rates (9 g m 2 hr À 1 ) and the runo coecients (12%) were very low at the scale of measurement (0 . 25 m 2 ). The slope position does not aect erosion rates when the measurements are carried out under extreme dry conditions during summer. The low runo rates found in summer under thunderstorms of high intensity (5 year return period) and the runon into surfaces with higher in®ltration rates resulted in no detectable direct surface runo (Hortonian) at the slope scale. This implies that erosion as a consequence of surface overland ¯ow will only take place during events of high magnitude (55 mm hr À 1 ) and low frequency (45 years). Vegetation is the most important factor determining the soil erosion and runo rates within the slope.