ADACH conducts laser surveys to Hili-17 archaeological sites in Al Ain

Hili-17 / House No. 1, after the excavation carried out in 1992

ABU DHABI - The Abu Dhabi Authority for Culture and Heritage (ADACH) commenced the measures required to maintain the Hili-17 site in Al Ain City, as part of a broader plan aimed at the re-development of natural and cultural resources of the archaeological Hili garden and present it to the public.
In order to start the activities of conservation without delaying research on this archaeological site of a great importance, it was necessary to have the full documentation of this site, so that its features, remaining image and surroundings are recoded.
While it is easy to measure and draw modern buildings with straight edges, mud structures often have bent walls and irregular surfaces that are difficult to display in a two-dimensional format. Moreover, because of the fragility of the walls, floors and other features, it was necessary to use methods of documentation that require a minimum contact between the surveyor and the construction model.

Hili017 in 2011: work in progress for documentation and conservation

To meet these challenges, a survey laser has been selected - a technology under which a given surface is expose to a beam of laser in order to build a digital three-dimensional model - to produce a detailed record of each of the Hili-17 building constructions. The level of accuracy in the laser surveying was at 3-5 mm with full three-dimensional coordination and GPS to pinpoint the geographical location.
Workers in the preservation of archaeology carefully reveal its original features

Hili-17, which is said to date back to about 1,000 years BC, is one of the archaeological sites belonging to the Iron Age. It is located on the north-western side of the archaeological Hili garden in Al Ain City. It comprises of three mud houses that underwent excavations and dated to different periods, the nucleus of one of the old villages.
Perhaps this site had been an industrial centre at the time because it contains stoves that are believed to have been used for the production of pottery. Further research will help to shed further light on the implications of this important site.
The buildings that underwent the excavations in the early 1990s have not received the necessary protection, and have degraded significantly during the past twenty years, where rain, wind and sand storms have hit its fragile mud walls of dirt, causing its decay and collapse and the loss of important features in it.
The laser survey was conducted over four days by an expert in cultural heritage sites. To facilitate the surveying process, the sand that was brought by the storms and accumulated over the years was removed carefully, so as to reveal the full height of the walls.
Laser survey from a high platform

Then a temporary bridge was raised on the site to facilitate surveying the top surfaces of the wall. More than 100 pieces were surveyed and over 3,000 digital images were taken. The photos will be installed onto a three-dimensional model to create a photographic detail of the structure of the building. This information will be used to come out with the plans and the division of the site into parts, while carrying out lifting operations of its remaining features.
Preliminary snapshot of the data collected in one scan

This is in addition to allowing the conservation team the ability to determine the place of small gaps and other areas that suffer from degradation, and record them. This record will be the basis in documenting future conservation measures at the site, which may include adding mud to some parts while putting some reinforcements and protective measures.
This three-dimensional model will facilitate research efforts for archaeologists by becoming familiar with it while the site is being maintained. It could also be used for the purposes of illustration and presentation to visitors who will have the ability to see areas that are secluded in order to ensure their protection.