Hydraulic Modelling and Erosion Vulnerability with Historical Approach in Eastern Ancient Civilization, Ilamian/Susa Civilization in UNESCO World Heritage, CHOQA Zanbil, 3200 BC

Atieh Mahmoudi Mozafar, Sadegh Partani, Narges Partani, Mahtab Asgharzadeh, Hadi Jarahi, Hedayat Hashemi

Tuesday 30 june 2015

8:30 - 8:45h at Mississippi (level 1)

Themes: (T) Sediment management and morphodynamics, (ST) Sediment transport mechanisms and modelling

Parallel session: 4A. Sediment - Erosion

Today’s Chogha Zanbil, the antique Elamite city of Dur Untash is situated in the vicinity of the river Dez in the region of Khuzestan/Iran at 48°31'16.93" east longitude and 32°00'32.61" north latitude. Susa, the next bigger city is to be found at a distance of about 40 kilometres. Dur Untash was not built on the shore of the river but on a plateau of 50 m height above the river level and was separated by a few smaller hills from the river. The main threat of the Tchogha Zanbil site is natural water erosion which is happens every years in fall and spring’s heavy flash rains. It develop the natural drains conveys’ upstream which in the future may reach the heritage’s structures. This research also revealed some new structures on the 3rd border of ancient city. There found some termination of drains which seems as the water reservoir or primary clarification tanks preparing the surface run-off discharging to surface water resources or recycling systems for reuse in domestic consumption. After technical studies on material and symmetric and geometric survey and modeling, it became clear as a hypothesis that they may be water storage and main collector of natural drains due to heavy rains. One of these structures has been survived during recent years and the other or buried under the 3rd border wall’s ruins. Also the survived one is threaded by surface erosion also. This research has tried to check out the erosion factors and estimate the erosion amount per year to find out the protection measures plan for more conservation of this valuable heritage. Figure 2 shows some erosion developments at the upstream. Also some faults are other threat sources of natural erosion and destruction like Bam Castle. Figure 3 also shows the mentioned faults. The research has done some field studies and laboratory tests, found out the soil characteristics and has modeled the erosion amount and transferred sediment in the sub-basins of heritage site via two famous models M&MF and modified MPCIAK. Maps which have been generated during these models illustrated briefly in the paper and final erosion amount calculated. Results led the researchers to identifying at risk sub-basins and important drainage for erosion control.