A near-fault probabilistic seismic hazard assessment for Yasouj,located in the Kazerun fault system,southwest Iran

Natural Hazards - The Kazerun fault system (KFS) is located in the central part of the Zagros, the most seismically active orogenic belt in the Iranian plateau. The city of Yasouj is located in the...     

Application assessment of GRACE and CHIRPS data in the Google Earth Engine to investigate their relation with groundwater resource changes(Northwestern region of Iran)

In recent years, drought has become a global issue, especially in arid and semi-arid areas. It is without doubt that the identification and monitoring of the drought phenomenon can help to reduce the damages that would occur. In addition, rain is one of the factors which directly affect the water levels of underground water reservoirs. This research applied a linear gradient regression method developed on the basis of GRACE, CHIRPS, and data from monitoring wells to investigate the groundwater storage changes.These data have been analyzed on the Google Earth Engine platform. In order to conduct temporal and spatial analyses, the water levels of the aquifer were generated from the monitoring wells and zoned into five classes. Also, the amount of water storage and rain from the year 2003 to 2017 in the West Azerbaijan Province were investigated using the GRACE satellite and the CHIRPS data, respectively. The results obtained from the GRACE satellite data show that the average water level in the underground reservoirs in Iran had started to decrease since 2008 and reached its peak in 2016 with an average decrease of 16 cm in that year. The average annual decline of groundwater level in the studied time period was 5 cm. A chart developed from the CHIRPS annual rainfall data indicates that the biggest decline in rainfall occurred in 2008, and the declining trend has remained steady. Linear analyses were made on GRACE with CHIRPS results and monitoring wells data separately, from which the correlation coefficients are between 86% and 97%, showing generally high correlations. Furthermore, the results obtained from the zoning of the aquifer showed that in the period of 2004 to 2016, due to the decrease in rainfall and the excessive withdrawal of groundwater, the water levels also decreased.     

An investigation into the fault patterns in the Chadegan region, west Iran: Evidence for dextral brittle transpressional tectonics in the Sanandaj-Sirjan Zone

The NW-SE trending Sanandaj-Sirjan Zone (SSZ) is the internal part of the Zagros continental collision zone, which mainly consists of metamorphic rocks deformed in a dextral transpressional zone. This dextral transpression is attributed to brittle deformation related to late Cenozoic Arabia-Eurasia oblique continental collision. Major NW-trending faults, including the Dalan, Garmdareh, Yasechah, Sheida, and Ben faults, are reverse faults with a dextral strike-slip component. These faults were displaced by NW-trending synthetic and NE-trending antithetic faults. There are also E-trending thrusts and N-trending normal faults developing in directions that are, respectively, almost normal and parallel to the major shortening direction. The NW-trending Ben, Yasechah, and Sheida faults are NE-dipping faults, and the Dalan and Garmdareh faults are SW-dipping faults. These faults indicate the presence of a transpressive flower structure zone that probably led to the exhumation of Jurassic high-grade metamorphic rocks, such as eclogite, in the central part of the study area.     

Remediation with surfactant foam of PCP-contaminated soil

An investigation was made into evaluating the capability of surfactants in the form of foam for removing the contaminant pentachlorophenol (PCP), a highly toxic, wood preservative, from soil. Several surfactants were investigated for their ability to make foam. Two of them, Triton X-100 and JBR425 (a rhamnolipid biosurfactant), generated foam with higher quality (99%) and higher stability than other surfactants. Triton X-100 and JBR425 were then used to investigate the removal efficiency in soils contaminated with pentachlorophenol (PCP). Triton X-100 showed better results in terms of final removal efficiency. Triton X-100 (1%) removed 85% and 84% of PCP from fine sand soil and sandy-silt, respectively, contaminated with 1000 mg/kg PCP. These values were 60% and 61% for JBR425 (1%). Of this, 66% and 57% of the PCP was removed by volatilization by Triton X-100 and 36% and 44% by JBR425. Further experiments with Triton X-100 indicated that 1% Triton X-100 removed more than 0.5% and that PCP removal was approximately the same for 1% Triton X-100 for a higher contaminant level (3000 mg/kg) but more pore volumes of foam were required for fine sand (23 pore volumes compared to 12). For the sandy-silt soil, PCP removal was higher for the higher contaminant level, 84% compared to 76%. More pore volumes were required (35 compared to 21). Comparison of liquid and foam injection of 1% Triton X-100 indicated that the foam removed more than twice as much PCP in all cases than the liquid surfactant solution. The results of this study on a sandy and sandy-silt media, thus, found that the foam can be used as a fluid to enhance soil remediation under low pressures compared to other fluids such as liquid surfactant solutions.     

A Predictive Model for Estimating the TBM Penetration Rate Based on Hybrid ICA-ANN and DEA-AHP Algorithms

Geotechnical and Geological Engineering - Predicting the penetration rate of tunnel boring machine (TBM) is a complex and challenging task that plays a crucial role in the schedule planning and...