Using lidar data to analyse natural geomorphometric and man-modified characteristics of Karstic landscape under forest cover

In this presentation, we studied possibilities for detection depressions in terrain under forest cover by use of airborne laser scanning data. Lidar uses light beams with the potential to penetrate gaps in forests / trees canopy and therefore gives researchers the record of the ground surface not easily detected under the trees with other methods, revealing among others several geomorphological historic and archaeological features. Laser pulse that returns from the ground is therefore providing important data for the development of digital elevation model (DEM), which is then used for further processing an analysis.

Two main objectives of this study are as follows:

1. To map and determine the geomorphometric characteristics of a large number of karstic sinkholes and to investigate the correlations between geomorphology and vegetation in areas with such characteristics as proposed by Kobal et. al. (2015). According to EU Regulation 1305/2013 on support for rural development EU members are supposed to map Areas with Natural Constraints (ANC) according to common biophysical criteria where “steep slope” is regarded as one of them. Traditional digital elevation model (DEM) is based on aerial photos and topographic maps providing DEM with insufficient resolution and accuracy, especially in forested karst areas (Kobal et. al. (2015). The proposed Lidar based method will provide researchers much more accurate data on slopes giving the possibility to delineate Areas with Natural Constrains with higher accuracy.

2. To map and determine visual remains of bomb craters and others historical heritages which are the result of cannon bombardment in the First World War in the western part of Slovenia, near the border with Italy. The preservation and promotion of this heritage, currently part of the forest soils' memory, are hampered by the canopy. This hampering effect is also a limit to the exhaustiveness of classical field surveys. Airborne laser scanning data overcome these constraints. Using Lidar data will enable us to develop criteria for delineation of “historic forest landscapes” as one of the important ecosystem services of forests in a Karstic Study area.