The project ordered by the Arab Potash Company, Jordan
The project took place in 2006 and was initiated by the Jordanian Arab Potash Company (www.arabpotash.com) that has long and mutually beneficial relations with Drakkar ltd. The company is producing potash from the Dead Sea by the special technology which implies a great volume of earth-moving work. The company has to erect and keep in working order the dams which form the artificial basins where water remains for a long time (up to a few months) before the potash extraction begins. Such a method is well known in chemical industry. During its stay in the basins water intensively evaporates witch increases salt (sodium chloride) solution concentration finally causing salt settling down as a sediment. That’s the way of water coarse refinement. Since the level of basins are higher than the Dead Sea they have to pump up the water into the basins and then it flows naturally back to the Sea. The dams robustness and reliability are of the great concern for the owner as it can cause the serious technical problems and threats to people.
The serious disaster happened in 2005 when one of the dams collapsed. The damage was estimated as much as 500 million USD. After that disaster the Arab Potash Company took a number of measures to improve the situation and prevent possible future troubles. After thinking the problem over the plan was proposed to carry out precise lidar survey of the whole territory to detect any even minor displacements (within 10-20 cm) on the surface which can indicate appearance of under-ground karstic hollows. The significant territory of the project and strict demand for accuracy made this project ideally suitable for the mobile lidar technology introduced by Drakkar ltd. The whole scope of work was fulfilled within 3 days and 5 potentially dangerous places were discovered. All of them were eventually checked by the company’s personal which fully confirmed the predictions were true.
To improve the geodetic accuracy of the resultant DTM some extra efforts were made to accompany lidar scanning points with GPS and leveling measurements. The total length of the surveyed project was about 15 km with a swath width up to 150-200 m. The typical cross-section is presented at the Figure.
With 500 m interval four geodetic marks were deployed in a line transversely to a dam axis. The project was done in cooperation with TRIG company.