Estimation of Runoff, Peak Discharge and Sediment Load at the Event Scale in a Medium‐Size Mediterranean Watershed Using the Annagnps Model

Abstract

In this paper, the Annualized Agricultural Non-Point Source (AnnAGNPS) model has been used to estimate runoff, peak discharge and sediment load at the event scale in a Mediterranean watershed. The study area is the Carapelle torrent, Southern Italy (area = 506 km 2 ), where continuous rainfall, streamflow and sediment load data are available. Nineteen flood events have been registered in the period 2007-2009 and were used for the application of the model.The aim of the paper is to evaluate the predictive accuracy of the model at the event scale, in a medium-size watershed, given the specific conditions of the semi-arid environments. A sensitivity analysis has been carried out to assign the correct parameterization: the mean normalized output variation of the most meaningful input parameters pointed out the influence of the curve number on runoff, peak discharge and sediment load predictions (values greater than 1); the MN Manning's roughness coefficient and K, C and P factors of the universal soil loss equation showed a moderate influence on sediment load simulations (values between 0Á5 and 1).The selection of the Soil Conservation Service synthetic storm types has been based on the observed storm events analysis to improve the peak discharge simulations. The model prediction has proved to be good for runoff (R 2 = 0Á74, NSE = 0Á75, W = 0Á92) and peak discharge (R 2 = 0Á85, NSE = 0Á70, W = 0Á94), and satisfactory for sediment yield (R 2 = 0Á70, NSE = 0Á63, W = 0Á91). The relative error is lower for high events; this result is quite interesting in semi-arid environments, where most of the annual sediment yield is concentrated in a few, severe events.

Effects of soil management techniques on soil water erosion in apricot orchards

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Agricultural land abandonment in Mediterranean environment provides ecosystem services via soil carbon sequestration

“…The impact of subsidies from the European Union on Mediterranean agriculture are relevant to understand changes in agricultural management (Shelef et al, 2016), but there are also environmental impacts such as changes in the hydrologic cycle and alterations in soil organic matter and biota that need more research (Bisantino et al, 2015;de Araújo et al, 2015). The effectiveness of the premiums, calculated as the rate between the overall value of payments obtained by the farmers over twenty years (Eq.…”

Rainfall simulation and Structure-from-Motion photogrammetry for the analysis of soil water erosion in Mediterranean vineyards

“…Extreme rainfall events that occur in the Mediterranean area are able to cause significant soil water erosion processes, especially when no protective material covers the soil ( Fig. 1) (Bisantino et al, 2015;Keesstra et al, 2016;Novara et al, 2016;Prosdocimi et al, 2016c). However, to reduce the high soil erosion rates, more conservation-minded soil management practices have also been used such as mulching (Cerdà et al, 2015;Costantini et al, 2015;Jordán et al, 2011;Prosdocimi et al, 2016bProsdocimi et al, , 2016c, cover crops (Novara et al, 2011), rock fragments (Blavet et al, 2009), natural grassing (Grimaldi et al, 2015;Mekonnen et al, 2015a;Mekuria et al, 2016;Raclot et al, 2009) and geotextiles (Giménez Morera et al, 2010;Mekonnen et al, 2015b;Mengistu et al, 2016).…”