Sediment delivery processes and agricultural non-point pollution in a Sicilian basin

Recent research has directed attention to the properties of the eroded mate rial because of its influence in deposition phenomena and in carrying capac ity of pollutant materials. In this paper, the spatial distribution of the content of nitrogen, phospho rus and total organic carbon is firstly deduced using the measurements carr ied out in 129 soil samples well distributed over the Sicilian Sparacia Bas in and a Kriging interpolation method. Then the load of each chemical was c alculated at morphological unit and basin scale using the above-mentioned s patial distributions and sediment yield values calculated by a parametric a pproach such as the revised universal soil loss equation (RUSLE) coupled wi th a spatial disaggregation criterion of sediment delivery processes. Final ly, at basin scale, a new expression of the enrichment ratio of a given pol lutant has been proposed; the enrichment ratio values were also related to the corresponding basin sediment delivery ratio values. (C) 2000 Silsoe Res earch Institute.