The present study was conducted in the suburban forest of Thessaloniki city (Seich Sou), which constitutes one of the most significant suburban forests in Greece. In 1997, more than the half of the forest area was destroyed by a wildfire, after which soil erosion and flood control works (check-dams) were constructed in the burned areas. The aim of the study is to estimate the annual soil erosion rate for the last 30 years (pre- and post-fire periods) applying the WaTEM/SEDEM model, in order to investigate the impact of this wildfire on soil erosion, the effectiveness of the flood- and erosion-control works and the level of forest regeneration. It is the first time that WaTEM/SEDEM was calibrated and validated in Greece, taking into account soil erosion records from the 18 check-dams that were constructed in the study area in 2001. The mean annual erosion rate was 0.0419 t/ha/year, 0.998 t/ha/year and 0.08 t/ha/year for the pre-fire period, the first 3 years and 20 years after the fire, respectively. The results showed a very low erosion rate for the pre-fire period, an expected significant increase 3 years after the wildfire and a gradual decrease in the subsequent years until 2021. However, it seems that the post-fire regeneration of the forest has not been fully achieved, since the annual soil erosion rate at the long-term post-fire period is double compared with the pre-fire period. Concerning the check-dams’ effectiveness, it was observed that after 20 years of operation, they were non-silted, and most of them retained a small amount of sediments. This fact could be attributed to multiple factors such as the very thin soil depth, fire severity and catchment geomorphology, though the main reason seems to be the time elapsed between fire occurrence and the check-dams’ construction. The results of this study advance/strengthen the knowledge concerning the pre/post-fire soil erosion processes in already degraded ecosystems, while the calibrated model could serve as a useful tool able to be applied in other Mediterranean catchments of similar characteristics.

The present study was conducted in the suburban forest “Seich Sou”, which is located at the north-east of Thessaloniki city (north Greece). “Seich Sou” is one of the most significant suburban forests of North Greece. However, many disastrous events have taken place in the suburban forest during the last 25 years, caused by either human interference or other biotic/abiotic factors, such as insect outbreaks. In the present study, erosion measurements and field data were collected using a combination of silt fences (USLE plots) and depositions retained behind the constructed check-dams, aiming to monitor the impact of the significant biotic and abiotic disturbances (forest fires, insect outbreaks, logging) in Seich Sou forest. Specifically, the aim of this study is to present a cost-effective and time saving methodology towards the achievement of accurate and reliable soil erosion measurements and field data acquisition. Additionally, the installation details, data recording and collection, field work, supplementary materials and the advantages of silt fences and check-dams are presented in detail, as well as the limitations of the methods and the difficulties during the installation, maintenance and data collection period. The proposed methodology could be effectively applied in many environments and in the context of varied purposes, to quantify the erosion and runoff processes with high accuracy, as well as to increase the accuracy of soil erosion modeling performance, through implementation of calibration and/or validation processes, which is a major issue for the scientific community.