Final Activity Report Summary - OLSEDYN (Assessment and prediction of sediment dynamics within olive orchards)
The main research result is that soil erosion processes in olive orchards are now much better understood. All measurements show that soil erosion in olive orchards is undoubtedly a serious environmental threat. Long-term historical average erosion rates that were derived from comparing ancient surfaces with the actual ones, indicate that each year 0.8 cm of fertile soil is lost. Given the shallow depth (<1 m) of many Mediterranean soils, in places, the fertile soil cover has already been lost completely. Measures of actual processes indicate the same dramatic soil losses.
During some extreme events, between 1.5 and 4.8 cm of soil loss was measured. These dynamics show how difficult prediction is. Nevertheless, using some novel modelling techniques, such as cellular automata-based soil erosion models, relatively good predictions were obtained over the longer term. Also, some general trends in sediment transport equations have been tested and it was found that a single equation describes well the behaviour of small rills to large gullies under field conditions. This will contribute to improved soil erosion models in the future.