ORIGINAL ARTICLES the Probability of Alborz Mountains Environmental

156 Research Journal of Fisheries and Hydrobiology, 6(3): 156-173, 2011 ISSN 1816-9112 ORIGINAL ARTICLES The Probability Of Alborz Mountains Environmental Pollution Due To Seismic Response Of Lar Dam Zaniar Tokmechi Department of Civil Engineering, Mahabad Branch, Islamic Azad University, Mahabad, Iran. ABSTRACT Lar Dam is a dam located in foot of Mount Damavand, Iran. It is one of the main sources of water for Tehran metropolitan region. Alborz, also written as Alburz, Elburz or Elborz, is a mountain range in northern Iran stretching from the borders of Azerbaijan and Armenia in the northwest to the southern end of the Caspian Sea, and ending in the east at the borders of Turkmenistan and Afghanistan. The tallest mountain in the Middle East, Mount Damavand, is located in the range. In this paper, the probability of environmental pollution due to heavy metals caused by LAR dam failure is studied. Finite Element and ZENGAR methods are used to analyze the probability of pollution at dam downstream. Different dam cross sections and various loading conditions are considered to study the effects of these factors on the seismic behavior of the dam. Results show that the effect of the highest cross section is not the most significant for heavy metals pollution at the dam down stream. Pollution coefficient due to stress along Y axis (Sy) is always the determinant pollution. While, in all sections Sx and Sy are the determinant parameter affecting downstream heavy metal pollution and normally are bigger than Sz. And, Sz which can never be a determinant. According to results, when the earthquake accelerations are bigger, maximum pollution coefficient due to tensile stress at dam basement is increased. While, the pollution due the maximum compressive stress at dam basement depends on both earthquake acceleration and loading condition. Key words: Environmental pollution, Seismic Response, Lar dam, ZENGAR, FEM Introduction The Alborz mountain range forms a barrier between the south Caspian and the Qazvin-Tehran plateau. It is only 60–130 km wide and consists of sedimentary series dating from Upper Devonian to Oligocene, prevalently Jurassic limestone over a granite core. Its higher elevations, in the Elburz Range forest steppe ecoregion, are arid with few trees, but its northern slopes, in the Caspian Hyrcanian mixed forests ecoregion, are lush and forested. The seismic action on dams is the most important to be considered in dams safety studies and its effects on the environmental pollution (United States Army Corps of Engineers, 1990). In 21st century, hydraulic power exploitation and hydraulic engineering construction have been improved in many countries. Some high dams over 200m, even 300m in height, have been built in many areas of the world (Jianping et al., 2006). Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms (Mohsenifar et al., 2011; Allahyaripur et al., 2011). Pollution can take the form of chemical substances or energy, such as noise, heat, or light. Pollutants, the elements of pollution, can be foreign substances or energies (Arabian and Entezarei, 2011), or naturally occurring; when naturally occurring, they are considered contaminants when they exceed natural levels (Arbabian et al., 2011; Hosseini and Sabouri, 2011). Pollution is often classed as point source or no point source pollution. Pollution has always been with us. According to articles in different journals soot found on ceilings of prehistoric caves provides ample evidence of the high levels of pollution that was associated with inadequate ventilation of open fires. The forging of metals appears to be a key turning point in the creation of significant air pollution levels outside the home (. Core samples of glaciers in Greenland indicate increases in pollution associated with Greek, Roman and Chinese metal production. According to the statistics, the construction regions in many areas, are notable for their high environmental pollution (Wang and Li, 2006; Qasim et al., 2010 a; Qasim et al., 2010 b). Therefore, environmental studies affected by the seismic safety of large dams is one of the key problems that need to be solved in the design of dams. While, difficulties exist in determining the seismic response of dams (United States Army Corps of Corresponding Author: Zaniar Tokmechi, Department of Civil Engineering, Mahabad Branch, Islamic Azad University, Mahabad, Iran. Tel: +98-918-873-1933, Fax: +98-871-3229437, E-mail: [email protected] 157 Res. J. Fish & Hydrobiol., 6(3): 156-173, 2011 Engineers, 1995). The most important difficulty is dams complex geometry and forms, motivated by the topography and geotechnical character of the implantation zone and controlling the project pollution effects. According to the previous studies, usually 2D models corresponding to the higher section the dam have been used in the structural seismic analyses of the dams (Fenves and Chopra, 1984). While, normally there is a lot of variation in the dam foundation geometry which can be extremely make the study of the dam downstream pollution difficult. In this paper, the probability of environmental pollution caused by LAR dam failure is studied. Finite Element and ZENGAR methods are used to analyze the probability of pollution at dam downstream. Different dam cross sections and various loading conditions are considered to study the effects of these factors on the probability of environmental pollution due to seismic behavior of the dam. Materials and Methods Lar Dam: Lar Dam is a dam located in foot of Mount Damavand, Iran. It is one of the main sources of water for Tehran metropolitan region. Figure 1 and 2 show the Lar dam and its place in Iran. Fig. 1:Lar dam Fig. 2: Lar dam place 158 Res. J. Fish & Hydrobiol., 6(3): 156-173, 2011 Fig. 3: Central Alborz Fig. 4: Damavand mount Construction: In the wake of the Amol water need increase, study and construction phases of an earth dam over the Lar river, in northeast of the city, on the elevated heights of the Kalanbasteh mountain, on the slope of Mount Damavand, in an area called Polour, at kilometer 65 of the Haraz Road (between AMOL and the city of Amol) started in 1974. The dam's construction work ended in 1981 and it started operation in 1984. One of the aims for building the Lar dam was to supply part of Amol drinking water need; it was not possible then to operate the dam at its nominal capacity however, because of water seepage problem. Water stored in the dam's reservoir is transferred to the Kalan and Lavark power plants, a distance of 3 kilometers from the Latyan Dam's reservoir, through the 20 kilometer long Kalan tunnel (3 meters in size). After electricity generation, the water joins and feeds the Latyan dam's reservoir. Uncontrolled growth and expansion of Tehran created such a situation that the existing water resources, i.e., Karaj, Latyan and Lar dams and the deep wells, which were supposed to be exploited only in the mounts of peak water consumption, were no longer capable of meeting the city's water demand, so inevitable abstraction from ground resources started to increase in a manner that at present situation, the quantity of drilled deep wells 159 Res. J. Fish & Hydrobiol., 6(3): 156-173, 2011 has amounted to 230 rings. In fact, in 1997, 1998, 1999 and 2000, it had been orderly abstracted, 317, 289, 374 and 357 Mm3 of water from groundwater resources of the city. Alborz Mountains: Alborz, also written as Alburz, Elburz or Elborz, is a mountain range in northern Iran stretching from the borders of Azerbaijan and Armenia in the northwest to the southern end of the Caspian Sea, and ending in the east at the borders of Turkmenistan and Afghanistan. The tallest mountain in the Middle East, Mount Damavand, is located in the range. Figure 3 and 4 show central Alborz map and Damavand mountain. The Alborz mountain range forms a barrier between the south Caspian and the Qazvin-Tehran plateau. It is only 60–130 km wide and consists of sedimentary series dating from Upper Devonian to Oligocene, prevalently Jurassic limestone over a granite core. Its higher elevations, in the Elburz Range forest steppe ecoregion, are arid with few trees, but its northern slopes, in the Caspian Hyrcanian mixed forests ecoregion, are lush and forested. Zoroastrians may identify the range with the dwelling place of the Peshyotan, and the Zoroastrian Ilm-e- Kshnoom sect identify Mount Davamand as the home of the Saheb-e-Dilan ('Masters of the Heart'). In his epic Shahnameh, the poet Ferdowsi speaks of the mountains "as though they lay in India." This could reflect older usage, for numerous high peaks were given the name and some even reflect it to this day, for example, Mount Elbrus in the Caucasus Mountains, and Mount Elbariz (Albariz, Jebal Barez) in the Kirman area above the Straits of Hormuz. As recently as the 19th century, a peak in the northernmost range in the Hindu Kush system, just south of Balkh, was recorded as Mount Elburz in British army maps. All these names reflect the same Iranian language compound, and share an identification as the legendary mountain Harā Bərəzaitī of the Avesta. Also due to its great snowy winters there are several ski resorts, some consider that a few of these are among the best in the world. Some of most important ones are Dizin, Shemshak, Tochal, and Darbandsar. Etymology: The name Elbrus is derived by metathesis from Alborz. The name Alborz is derived from that of Harā Bərəzaitī, a legendary mountain in the Avesta. Harā Bərəzaitī reflects Proto-Iranian *Harā Bzatī. *Bzatī is the feminine form of the adjective *bzant- "high", the ancestor of modern Persian boland and Barz/Berazandeh.

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