QE413 : The effect of flow regime of Zayandehrood River on ground subsidence in the area of historical structures in Esfahan
Thesis > Central Library of Shahrood University > Geosciences > PhD > 2018
Authors:
Abstarct: The city of Isfahan, with its world-famous historic buildings, as well as the existence of evidence of subsidence in this area, requires careful study of the possibility of subsidence. Zayandehrood River is known as the main source of recharging for the aquifer in Isfahan. But in recent years, the river has dried and The withdrawal of groundwater has intensified. Which has led to a drop in groundwater level, in just a few months to 20 meters. These factors will be a strong reason for subsidence. Investigating the laxyers of the city of Isfahan showed that the bed of Isfahan is often composed of three main laxyers. These three laxyers are from the surface to the depth, including the fine-grained, intermediate-grained, and fine-grained laxyers, respectively. With this method, hydraulic conductivity can be achieved by using gradation curves. Then, with the help of this equation and the ground water level fluctuation in the dry and when water flow in the river, the aquifer recharge rate from the river was calculated to be about 0.7 m3/sec in a distance of 16 kilometers. This amount of recharge was also obtained by the GMS numerical model of about 0.9 m3/sec. The results of the model showed that if there is no water in the river for five years, the ground water level will drop by more than 3 meters. Also, if there is only one month in the year the river has a water flow, the ground water level loses a lot of current conditions. According to the subsidence potential zonation map, the maximum potential hazard is a zone with an ultimate radius of 1500 meters in the north and 400 meters in the south of the river from the western entrance of the city to the nearby jobi bridge. The eastern part of the city, near Shahrestan bridge and the southern regions (University of Isfahan) are among the safest areas of the city from the point of view of subsidence.
Keywords:
#Isfahan aquifer #subsidence #hydraulic conductivity #GMS #surface water and underground water interaction. Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
Visitor: