Relations between the water, soil and seed losses in badlands. Influence of gradient

A. Cerdá, P. García-Fayos

Abstract


By means of simulated rainfall experiments, the dynamics of the soil, water and seed losses are studied in degraded soils of gullies. The runoff discharge reached after 40 minutes atan intensity of 55 mm h1 is very high. Ponding and runojf are almost instantaneous and the runojf curves are very steep because the low infiltration rates (2 mm h1 ). The aforementioned characteristics together with the high erodibility of the soils (sediment concentration is higher than 70 g l-1 ) result in very high erosion rates (3 Kg m2 h1 ). On the other hand, the seed losses are very low. Further studies will be necessary to explain the non-existence and the non-regeneration of the vegetation cover in the gullies.
The time to ponding and time to runoff has a positive relationship (r2 = O, 71), as does the runo.ff sediment concentration and the erosion rates (r2 = 0,83). Less defined relationships exist between the runo.ff coef ficient and the erosion rate (r2 =0,35), the erosion rate and seed losses (r2 = 0,26), and the runoff coefficient and seed losses (r2 = 0,58).



DOI: http://dx.doi.org/10.18172/cig.1008

© Universidad de La Rioja, 2013

ISSN 0211-6820

EISSN 1697-9540