Interplay between land use changes and soil erosion in a small mountainous catchment in southern Italy

Land use is one of the most important factors controlling soil erosion. Moreover, erosion rates may vary through time as a response to land use changes. The aim of this work was to analyze the main land use changes in the last 60 years and to assess the relationships between them and spatial and temporal distribution of soil loss at catchment scale. The study was carried out in the Torano catchment (northern Calabria), which is representative of wide sectors of Calabria Region, where the overall soil erosion susceptibility is high. Aerial photos interpretation of different years (1954 and 2012), and field survey were used to assess and map types and variations of land use in the study area. The mean annual rate of soil erosion and the effects of land use changes on soil erosion since 1954 to 2014 were analyzed by using the revised universal soil loss equation (RUSLE) in a GIS environment. Results showed that the total soil loss estimated in the Torano catchment was 2216.76 t yr-1 in 1954, 3242.22 t yr-1 in 2014. Furthermore, the rate of mean annual soil loss increased from 4.30 t ha-1 yr-1 in 1954 to 6.29 t ha-1 yr-1 in 2014. Increasing erosion rates was mainly caused by the transformation of natural forest, scrub and pasture areas into crop fields. In addition, from 1954 to 2014 the barren land progressively increased from 0.2% to more than 2 %; in these areas and the highest soil loss values were observed. The increase of cultivated and barren lands, from 1954 to 2014, caused a 46.3 % increase soil loss. Therefore, the spatio-temporal changes of land use in the Torano catchment had an important role on soil erosion control.