Evaluating and modelling the hydrological and erosive behaviour of an olive orchard microcatchment under no‐tillage with bare soil in Spain

Abstract

Despite the high risk of erosion in olive orchards located in mountainous areas in Spain, little research has been carried out to account for the complexity and interaction of the natural processes of runoff and soil erosion on the catchment scale or small catchment scale. In this study, a microcatchment of 6·7 ha in a mountainous area under no-tillage farming with bare soil was set up to record runoff and sediment. Soil erosion and runoff patterns were monitored over a two-year period. Totally, 22 events were observed. The data were analysed, and then used to calibrate the AnnAGNPS model, which allowed us to complete the data period and describe the hydrological and erosive behaviour on a monthly and annual basis. A high variability in catchment responses was observed, due to differences in the storms and to the effect of the surface soil moisture content. Maximum intensities of 10 and 30 min determined the final runoff values while the total sediment loads were dependent on the rainfall depth. The impact of management on the reduction of porosity can explain the relationship between runoff and intensity in the microcatchment. However, the impact of the spatial scale meant that the transport of sediment required substantial rainfall depths to ensure a continuous flow from the hillslopes. The results of the calibration (E > 0·60 and r > 0·75) on the event and monthly scale confirmed the applicability of AnnAGNPS to predict runoff and erosion in the microcatchment. The predicted average runoff coefficient was 3·3% for the study period and the total average sediment loads, 1·3 Mg/ha/yr. Despite these low values, the model simulation showed that much larger runoff coefficients and soil losses can be expected for periods with several consecutive years in which the annual rainfall depth was over 500 mm. The use of cover is recommended to prevent the high levels of erosion associated with these conditions.

Characteristics and importance of rill and gully erosion: a case study in a small catchment of a marginal olive grove

“…Pastor et al, 2001;Francia et al 2006;Gómez et al, 2004Gómez et al, , 2009 or total sediment load at the catchment scale (Taguas et al, 2009;Gómez et al, 2014b). In few studies has the identification of the dominant erosive processes and its dynamic on commercial farms been explored.…”

Vulnerability of Soil and Water in Mediterranean Agro-Forestry Systems

“…This behavior is in part responsible for an almost impermeable layer (horizon Bt), characteristic of Luvisols. The significant variability in runoff is justified not only by differences in characteristics of storms and surface soil moisture content, but also by preceding long dry periods which were likely to ease the effects of rainfall [41,42]. So, the event occurred on (Figure 10).…”

Modeling the spatial distribution of water erosion within a Spanish olive orchard microcatchment using the SEDD model

“…In small catchments in Southern Spain, Cammeraat (2004) also observed these features. However, in Andalusia under Atlantic influence, with a more humid regime and deeper soils, accumulated rainfall depth has been found to play a more important role than the intensity of the hydrological and erosive response in an olive microcatchment under no-tillage (Taguas et al, 2009). This difference in the hydrological response between western and eastern catchments in Andalusia has been well described by authors such as Puigdefábregas et al (1998).…”