Geological Environment and Engineering
Ahmad Abbasnejad
Abstract
The purpose of this study is: to determine the geomorphological setting; to assess earthquake, flood, and subsidence hazards, as well as to evaluate the landscape of Iranian urban areas, based on geomorphological criteria. To access the aim, 210 cities, each one having more than 50,000 population, were ...
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The purpose of this study is: to determine the geomorphological setting; to assess earthquake, flood, and subsidence hazards, as well as to evaluate the landscape of Iranian urban areas, based on geomorphological criteria. To access the aim, 210 cities, each one having more than 50,000 population, were investigated. In this study, Google Earth and satellite pictures, aerial photographs, and geological and geomorphological maps were used and, if needed, field investigations were undertaken. This study showed that the number of urban areas totally or partly lie on alluvial fans, flat surfaces, terraces, synclines, piedmonts, anticlines, and deltas are 103, 34, 26, 39, 27, 8, and 11 cases, respectively. The numbers on volcanic cones, cliffs, and wetlands are only 2, 1, and 1 cases, respectively. Also, 158 cases lie only on one landform and the remaining 52 cases predominately lie on two kinds of landforms. There are 82 and 90 cities at the high threat of earthquake and flood and the numbr of cities at the threat of surficial and qanat subsidence are 60 and 47 cases, respectively. The urban areas with uniform and good landscapes are 71 and 52 cases, respectively. The presented table demonstrates the geomorphological settings; the earthquake, flood and subsidence hazard levels and the landscape status of the 210 studied urban areas.
Petrology
Ahmad Khaiatzadeh; Ahmad Abbasnejad; Hojjatolah Ranjbar; Hamid Ahmadipour; Behnam Abbasnejad
Abstract
Damavand is one of the most potential volcanoes of Iran for future eruption. Such indicators as having a slightly- eroded cone, presence of many thermal springs, eruption activity in Late Quaternary, as well as the progression of the generating tectonic regime, all, attest this claim. The intensity of ...
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Damavand is one of the most potential volcanoes of Iran for future eruption. Such indicators as having a slightly- eroded cone, presence of many thermal springs, eruption activity in Late Quaternary, as well as the progression of the generating tectonic regime, all, attest this claim. The intensity of eruption is anticipated to be about 3-5 in Volcanic Explosivity Index (VEI) scale. As a result, such hazards as tephra (ash), nuee ardente, lava flow and lahar may pose problems. Thus, this study deals with zoning these hazards. For zoning, Digital Elevation Models (DEM= 30 m), Landsat ESTM+ pictures as well as Arc GIS, ENVI and VORIS softwares were employed, and for construction of nuee ardente- hazard zoning, Malin and Sheridan (1982) model were used. Atmospheric data for the spread of ashes were taken for NCER/NCAR center. Lava flow routes were determined using a simulation model which is based on the assumption that topography plays the main role on the route of flow, and lavas flow from a point to the nearby one if their differences are positive. In order to construct lahar hazard map, locations of main troughlines on the cone and around the volcano were determined and lahar invasion areas were determined using a proper buffer zone. Based on this study, volcanic ash plume will form at the east of volcano and a number of towns and villages would be threatened. Lava flows and nuee ardentes would threaten some villages around the cone. Lahars would flow via throughlines on the cone and arrive the main vallies around it (Hezar and Delichai). They would threaten many residential areas in their route. The prepared hazard maps are useful and necessary for management of these hazards.
Y Nazari; A Abbasnejad
Abstract
The Rayen plain, which is about 1900km2 in area is considered as a part of the Lut drainage basin and is located in the southwest of Lut and eastern slopes of the HezarMountain. This plain lies at the 110km southeast of Kerman city. Geographically, it is at 57˚, 13' to 57˚, 54' eastern longitude and ...
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The Rayen plain, which is about 1900km2 in area is considered as a part of the Lut drainage basin and is located in the southwest of Lut and eastern slopes of the HezarMountain. This plain lies at the 110km southeast of Kerman city. Geographically, it is at 57˚, 13' to 57˚, 54' eastern longitude and 29˚, 23' to 29˚, 52' northern latitude. The average height of this plain is about 2600m above msl. Given the location of the plain at the vicinity of the Urmiah- Dokhtar volcanic Belt and considering the role of eruptions as well as volcanic rocks and hydrothermal activities on the concentration of arsenic and the role of this element in environmental problems, this study was performed on the concentration of arsenic in groundwater. In order to determine the variations and source of arsenic, in all,29 samples were collected from the water points (springs, qanats and wells).Subsequently, the concentration of As, major cations and anions(Na+, K+, Ca2+ , Mg2+,Cl-,SO4-,HCO3-), NO3-,F-, as well as EC,TDS, alkalinity and total hardness were determined. Accordingly, isoconcentration map and correlation diagram were prepared and statistical analysis including Principal Component Analysis (PCA) and Cluster Analysis (CA)were carried out. The arsenic concentration in groundwater of this plain varies from 0.1 ppb up to 248.4 ppb with an average of 21.6 ppb. Based on the statistical analysis, arsenic concentration shows positive correlation with pH. The intrusion of hydrothermal waters into the aquifer and desorption from oxides and hydroxides of iron are considered as the main causes of high-arsenic level in some parts of this plain.
R. Hassanzadeh; A. Abbasnejad; A. Alavi; E. Sharifi Teshnizi
Abstract
In this article we examine the siesmicity of Kerman city. This city is located in a compressional graben which is bordered by several active faults, some of them are able to trigger an earthquake even stronger than Ms=7.0. Numerous historical earthquakes had occurred around the city which caused minor ...
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In this article we examine the siesmicity of Kerman city. This city is located in a compressional graben which is bordered by several active faults, some of them are able to trigger an earthquake even stronger than Ms=7.0. Numerous historical earthquakes had occurred around the city which caused minor damage to the building. For seismic evaluation of Kerman city both probabilistic and deterministic methods have been taken into consideration. Accordingly, peak ground acceleration due to 15 fault segments can exceed greater than 0.2g. The intensity scale resulting from earthquakes by Kerman – Zangiabad, North Kerman and Ekhteiarabad faults would be around IXMMI in the city. In order to assess the site effect, semi detailed micro zoning was carried out by combining micro tremor and sediment facies maps using GIS. The thick young sediments would amplify the intensity to X+ MMI. Based on the resulting map, the intensity scale would increase in central, western as well as some localities of the southern part of Kerman and many buildings would be damaged by such intensity scale.
