Abstract:

During the last years the major threat for the deforested areas of the Crete island,
especially the area of Moussouron municipality, is the quick wash out of soil material. The wash out of soil material, due to logging activities or fire events, obstracts efforts for reforestation and natural reconstruction of the site. For the needs of our research, the field experiments were applied at a high slope area situated at Moussouron municipality (Crete island - South Greece), where major
fire events recently took place and caused serious damages at the vegetation. In
specific, neighboring areas of approximately 2.6km2 and 3.2km2 have been burnt in
2003 and 2004, respectively. This case study area is mainly characterized by the Mediterranean climate, having extended dry periods during summer (5% of total rainfall) and periods with intensive rainfall during winter (95% of total rainfall). The area presents high relief alterations with intense slopes (~65% of the area has slopes over 20 degrees) and lithologically is mainly characterized by two basic formations; carbonate rocks at higher and schists at the lower altitudes. The aforementioned characteristics have caused the soil to intensively wash out just after the fires occurred. The main purpose of this research is to evaluate the correspondence between the amount of eroded material and the rain intensity, at conditions of recently burnt areas. In order to approach the problem, tree trunks in a parallel to the contour lines arrangement, were installed. This way the study area was split in numerous plots with predefined dimensions and precisely measured slopes. Just after each intense rainfall, thickness measurements of accumulated material were performed at each one of the tree trunks, while the runoff material was also estimated at the lowest parts of each plot. Αt the same time, using a rain gauge, rain intensity was also measured, in order to correlate this factor to the overall soil
washout. The research, performed within a period of 20 months with a total of 18 intense rain events, concludes to the rates of denudation and soil washout at non protected deforested areas and at the same time at areas were tree trunks were put as a prevention method. Particular preservation strategies and research methodologies adjusted to the needs of specific areas, may indeed act in favour of natural resources and retain ecological balance.