فهرست مطالب

ECOPERSIA - No. 2, 2012
  • No. 2, 2012
  • 88 صفحه،
  • تاریخ انتشار: 1391/01/25
  • تعداد عناوین: 7
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  • Homayoun Khoshravan*, Somayeh Rouhanizadeh Page 81
    We measured the impacts of coastal modification on beach erosion and beach retreat conditions, selecting the Miankaleh Region as an example of a complex high-pressure free zone with high levels of engineering and tourism activity. Nine sampling transects, stretching from the shoreline to a 10 meter depth, were defined and 36 sediment samples were collected from the sea bed at depths of 1, 3, 5, and 10 m. After conducting laboratory tests, data were analyzed in terms of sediment dynamic parameters such as grain size, sediment size distribution, mean, median, skewness, kurtosis, standard deviation, and mineral composition. Beach structure and morphodynamic conditions were assessed in the Miankaleh region, by means of satellite image interpretation and field surveys. Results show that from 1978 until the present the average rate of beach retreat rapidly increased due to sea level rise and coastal constructions that have resulted in a progressive increase in sea level height in this region. Erosion vulnerability hazards have also increased in the eastern part of the study area and deposition processes have developed in the western Amirabad region.
  • Asghar Kouhpeima, Sadat Feiznia, Hassan Ahmadi, Seyed Ali Asghar Hashemi Page 93
    Sediment-related environmental problems pose a serious threat to sustainable land management in many developing countries, including Iran. Information regarding sediment sources represents a key requirement from the management perspective since identification of sediment sources is a precursor to the design of effective sediment management and control strategies. The fingerprinting approach has increasingly been adopted as an alternative to assembling such information. A wide range of fingerprint properties has been used as a means of discriminating potential sediment sources. However, determining the ability of these properties is very important in the design of cost-effective catchment management strategies before each study. This contribution addresses the ability of two acid extractable metals (Co and Cr) that were used extensively in previous studies to be used to differentiate sediment sources. The results of the statistical analysis demonstrate that no single property is capable of classifying the source material samples into the correct source categories at the Amrovan drainage basins. In the case of the Atary drainage basin, Cr and Co were found in only 47.5 and 43.8% of the source material samples respectively. According to the result obtained, it is recommended that acid extractable metals for sediment sources differentiation in conjunction with the composite of other properties to improve sediment source discrimination.
  • Massoud Bagherzadeh Karimi*, Ramiz Mammedov, Fariba Fathi Saghezchi Page 101
    Urmia Lake and its surroundng wetlands have been severely affected by recent droughts (1998–2003) and a considerable decrease in inflow has affected lake ecosystem components. Integrated ecosystem-based management is a useful managing tool for the wise use and biodiversity conservation of wetlands. In the process of developing an integrated ecosystem-based management model for Urmia Lake, the identification of key stakeholders is of primary importance. In this research, stakeholder analysis is used as an effective tool for establishing collaborative management in the Urmia Lake catchment in terms of the following parameters and
    Objectives
    almost all stakeholders receive multiple benefits from Urmia Lake, either directly or indirectly; almost all stakeholders also cause impacts on the lake ecosystem, many of which result from activities that take place in areas located within in the Urmia catchment but far from the lake. In general, the stakeholders who receive the most benefits seem to cause the lowest impact (for example, Environmental groups), while those who receive fewer benefits may have larger impacts (for example, water resource managers). Recognizing that all stakeholders affect the lake in one way or another is an important concept that promotes the ethic that future management of the Lake should regarded as a shared responsibility between all stakeholders.
  • Ali Akbar Zinatizadeh*, Aazam Akhbari, Mehrdad Farhadian, Yadollah Mansouri, Meghdad Pirsaheb, Reza Amirsaie Page 111
    A bench scale aerobic sequencing batch reactor (SBR) was evaluated in terms of its potential to treat synthetic dairy wastewater. The 2-l plexiglass bioreactor was supplied with oxygen via a fine bubble air diffuser, fed with synthetic dairy wastewater under various operational conditions. To analyze the process, three significant independent variables — influent chemical oxygen demand (COD), mixed liquor volatile suspended solids (MLVSS), and aeration time — were assessed. Three dependent process and quality parameters (as process responses) were also evaluated: total COD removal efficiency, sludge volume index (SVI) and final pH. The experiments were based on a central composite design (CCD) and analyzed using response surface methodology (RSM). The treatment was limited to the following concentration regimes: COD (1000, 3000 and 5000 mg/l), MLVSS (3000, 5000 and 7000 mg/l) and aeration time (2, 10 and 18 h). Maximum COD removal efficiency (of 96.5%) was obtained for an influent with the following characteristics: CODin: 3000 mg/l, MLVSS 5000 mg/l, and aeration time of 18 h. The study demonstrated the capability of aerobic SBRs for high COD removal from dairy industrial wastewater. Easy operation, low cost, and minimal sludge bulking condition were some of advantages of the SBR system as an option for biological treatment of medium-strength industrial wastewater. The present study provides valuable information about relationships between quality and process parameters for different values of operating variables.
  • Abbas Farshad* Page 125
    The term degradation is used to specify the status of the environment. It is often associated with ‘improper use’. ‘Use’ also implies environmental aspects other than physical ones and implies that the more intensive the use, the more susceptible the environment is to degradation, particularly if proper care for the environment is lacking. The question is, and has always been, how to map something which, apart from the physical aspects of landscape, is also influenced by socio-cultural and economic issues? The common approach in mapping degradation is based on indicators and the intention of this paper is to present three case studies: the Tabernas-Sorbas area in Spain; Iran (at the country level) and the Pico de Tancitaro area in Mexico. The geopedological map is combined with the land use-based map to produce the basis for the extraction of a considerable number of indicators.
  • Ghasem Ali Dianati Tilaki*, Hossein Naderi Nasrabad, Jalal Abdollahi Page 147
    The relationship between topography, soil factors, and distribution of ecological vegetation groups in the Nodoushan arid rangelands of Yazd province (Iran) was investigated. The present species were recorded in each vegetation group using a randomized-systematic sampling method. Plant cover and density were estimated quantitatively using the transect and quadrate methods, and the two-way indicator species analysis (TWINSPAN), after which vegetation was classified into different groups. Soil samples were taken from 0–30 cm in each quadrat. In each vegetation group, 20 environmental variables including altitude, slope, aspect, percentage of bare rock, grazing intensity, percentage of gravel, soluble ions (Na+, K+, Mg2+, Ca2+), total nitrogen, organic matter, lime, gypsum, EC, pH, and percentage of sand, silt and clay were measured. Multivariate techniques including detrended correspondence analysis (DCA) were used to analyze the collected data. The results showed that the vegetation distribution was related to elevation, slope, and soil characteristics such as texture, organic matter, gypsum, acidity, lime, and gravity percentage.
  • Hasan Fazli* Page 157
    This study evaluates changes in species composition, catch, and CPUE of three species of kilkas in the Caspian Sea from 1961 to 2009. The effects of fluctuations in sea level rise and fall on the catch of kilka as well as the impacts of a recent invasion by Mnemiopsis leidyi (Ctenophora) were assessed in terms of species composition and CPUE of kilkas in the Iranian coastal region of the Caspian Sea. We found a negative correlation between long-term sea level changes and total catch (R2 = –0.56; P<0.001, which significantly declined in 1995 when the sea level increased to its highest level. Comparing catch per unit effort (CPUE) values during the pre-invasion (1996–1999) and post-invasion (2000–2009) periods indicated significant declines in anchovy and bigeye kilka, while common kilka increased significantly after the ctenophore invasion. During 2000–2009 overfishing, together with various environmental impacts following the introduction of Mnemiopsis, were major factors that contributed to changes in species composition and the collapse of kilka stocks in the Caspian Sea.