Determining rates of erosion of an earth pillar by terrestrial laser scanning

Abstract EN

This paper will show how a three-dimensional (3D) terrestrial laser scanning system can be used to assess the erosion of a sample earth pillar located in Selime in the Cappadocia region of central Turkey.

These pillars are known locally as ‘Fairy Chimneys’; they are a wonder of both the natural and cultural worlds and have importance from historical perspectives.

Sixty million years ago, the region was formed from soft layers of lava and ash spewed out by the Erciyes, Hasan, and Gullu mountains.

The landscape was then abraded by rain and wind over the years and the earth pillars were formed from the tuff.

Due to atmospheric effects the pillars are undergoing chemical and physical deterioration.

In order to conserve the earth pillars, an understanding of the deterioration phenomenon of the tuff is essential.

In the last years, three-dimensional (3D) terrestrial laser scanning systems have been very successfully employed in many engineering applications.

The high quantity and precision of the measured points enable the user to generate realistic and 3D illustrations of complex objects.

The sample earth pillar in Selime was modeled in 3D by terrestrial laser scanning three times during two six-month periods with an average of 10 mm horizontal and vertical intervals on the surface.

The volume differences were computed from the same volume surface for each period and these differences determined whether erosion had taken place.

At the end of the study, it was detected that there was partial erosion on this earth pillar resulting from physical intervention.