فهرست مطالب

علوم محیطی - سال پنجم شماره 2 (پیاپی 18، زمستان 1386)
  • سال پنجم شماره 2 (پیاپی 18، زمستان 1386)
  • 102 صفحه، بهای روی جلد: 10,000ريال
  • تاریخ انتشار: 1386/11/16
  • تعداد عناوین: 8
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  • Janet Blake Page 1
    The notion of applying a participatory approach to various areas of both environmental protection and development has gained ground in international policy- and law-making since the adoption of the Rio Declaration in 1992. The Declaration presents the participatory approach as an important procedural aspect of environmental management and decision-making within sustainable development and requires governments to employ it as far as possible. The Declaration also recognises the important and sometimes central role played by local and indigenous communities and their knowledge and practices – their intangible cultural heritage - in ensuring that the use of natural resources is environmentally sustainable. Taken together, these two principles can be understood to require governments to ensure a high degree of local community involvement at all stages of environmental protection (from policy-making to management), an approach endorsed in various environmental treaties adopted in or since 1992. The Convention on Safeguarding Intangible Cultural Heritage adopted by UNESCO in 2003 is the most recent treaty in this area to take this approach and it is interesting both for the way it places the community at the centre of actions for its implementation and also since it establishes an intergovernmental Committee whose main task involves the development of operational directives for this treaty. Since employing a participatory approach that requires the direct involvement of local communities in areas traditionally reserved to government is a complex and difficult question, it is hoped that the future practice of the intergovernmental Committee of the 2003 Convention may provide guidance on this not only for that treaty but also for other environmental treaties. Given the uncertainty surrounding both the identification of these “communities” referred to in environmental treaties and, more problematically, the exact content of their “participation” in environmental protection, I wish here to examine these further in an attempt to give them more clarity.
  • Khadijeh Moradi, Kiumars Zarafshani Page 15
    In developing countries poverty is more prevalent and usually deeper in rural regions than in urban areas. The rural poor depend on natural resources for their subsistence, and their behaviour affects a significant portion of those resources. In many developing countries such as Iran, environmental resources are used mainly as inputs in household production or in small-scale production units. Among small-scale rural technology, biogas plants present a suitable alternative option for preserving environmental resources from deforestation, land degradation, and desertification. The purpose of this qualitative research is to introduce biogas technology to one of the poor and degraded communities in Qezel village of eastern Kermanshah Province. A focus group of twenty rural residents was organized to identify potential users of the polyethylene biogas plant. During focus group discussions, one household who showed interest in the project was specifically selected. A four step cyclical action research process was used as a guiding principle to introduce and set up a biogas plant among a Qezel rural household. Recommendations are given based on the result of the study. Results revealed that a rural household in Qezel village welcomed biogas technology and found it to be useful in their cooking tasks. The implications of this study suggest that policy makers should launch a national biogas programme across the country.
  • Gholam Hossein Kiani, Seyed Kazem Sadr, Iraj Saleh Page 21
    Water markets have been introduced recently as an appropriate alternative to bureaucratic control and allocation of water resources. Water markets increase water use efficiency through the transfer of water to higher value uses. Several studies have been carried out to simulate hypothetical water markets under conditions of both certainty and uncertainty to show the potential gains that can be achieved by market participants. However, the effect of water supply and price risk has seldom been analyzed by the water market models presented. This study endeavours to introduce output and water input price risks into the water market models. For this purpose, an econometric mean-variance model, under output price risk and water market price risk is theoretically developed to derive demand and supply functions. This approach facilitates empirical estimation of demand and supply functions in actually formed water markets.
  • Hassan Hoveid, Gholamreza Nabi Bidhendi, Hamid Reza Jafari, Touraj Nasrabadi, Toktam Shahriari Page 31
    During recent years, surface water resources supplying Tehran's potable water – Karaj, Lar and Jajrood Rivers – are contaminated with different microorganisms due to population growth. Additionally, the amount of organic materials generating odor, taste and color in the surface water has increased sharply. By considering the trihalomethane (THM) production potential of dissolved chlorine in reaction with innocuous humic substances, future use of chlorine as a disinfectant in Tehran's drinking water is clouded in uncertainty. Accordingly, the use of ozone as another alternative was taken in to consideration for disinfection of drinking water in this mega city. In order to evaluate advantages and disadvantages of water ozonation a pilot with a generating capacity of 4 gr ozone per hour was designed. This study was performed between April and September 2005 and Tehran Pars watertreatment plant in the Northeast of Tehran was chosen for the case study. Bacteria removal was considered to be at highest level in all monthly samples. Different ozone contact times and dosages were tested in the deactivation of nematodes and the results showed the perfect removal in specified periods. Although the initial investment for construction and implementation of the required apparatuses is relatively high, since the raw material for ozone generation is air, the use of ozone is financially justifiable during the predicted time of operation. Moreover, the transfer and storage of ozone is much easier in comparison with chlorine which is currently in use. Unlike chlorine, the use of ozone as a disinfectant does not have the potential of THMs generation. On the other hand, ozone must be generated on site and is instable in water. Therefore, a continuous and precise monitoring and maintenance process must be taken in to consideration. Furthermore, due to high corrosive potential of ozone, special resistant materials must be used in the applied instruments.
  • Hadi Veisi, Hadi Hematyar, Hadi Azar Kerdar Page 39
    This study determines the relationship between students’ knowledge and their perceptions towards sustainable agriculture. 100 senior agricultural students from 10 different majors at the University of Tehran were selected by simple random method. A 10-point scale was used to measure students’ perceptions and knowledge towards sustainable agriculture. The validity was confirmed by a panel of experts and the scale was subjected to reliability testing using data collectedin the pilot study. The Cronbach alpha coefficients were 0.62 and 0.86 for the scales of perception and knowledge, respectively. Students rated themselves as a group having limited knowledge of sustainable agriculture policy but high for their attitudes, especially for environment and livelihood (security food). The findings revealedthat attitude dimension of environment and food security, and the knowledge dimension of practice and sustainable agricultural systems had specifically a greater role in determining relationship between students’ attitudes and their knowledge towards sustainable agriculture. Overall, to enhance students’ attitudes towards sustainable agriculture, it is suggested that more attention be paid to the concepts of policy determination and familiarize students with sustainable agriculture in agricultural curriculum development.
  • Amin Rastandeh Page 51
    In the present article, the author seeks to define sustainable greenway planning along coastal areas in the North and South of Iran based both on the historical heritages of green routes in the country and international greenway theory that is concerned with American and British definitions. For this reason, in the half first of this paper, the principles and concepts of historical Persian green routes have been scrutinized and identified and then, in the second half of the paper, according to the historical and cultural backgrounds and regional context of these coastal areas, an applied multi-functional greenway plan for settlements in the aforementioned regions has been proposed. Finally, the author concludes that, in the present century, local authorities have to pay attention both to regional conditions and international ideas of the same period to achieve landscape and environmental sustainability. It can be mentioned that in this article, the author used academic resources and applied an analyzing-describing method as a scientific research method. In addition, the two coastal cities of Anzali, on the Caspian Sea, and Bushehr, on the Persian Gulf, have been analyzed.
  • Hamid Alizadeh Ketek Lahijani, Vahid Tavakoli, Abdol Hossein Amini Page 65
    Rivers that flow from the Iranian coast to the Caspian Sea encompass 135,000 km2 of that catchment’s basin and supply 40 million ton sediment to the Caspian coast annually. The dynamics of river mouths and deltas are studied using hydrological data of the rivers, air photos, satellite images and geological and geomorphological maps as well as field observations and sediment sampling. Results from this study show that the morphology of the river mouths and deltas are mainly controlled by marine (ware-induced currents and sea level changes) and fluvial processes. Among these factors, sea level and riparian sediment supply have great variability. Analysis of hydrological data revealed that, during the past few decades with increasing human activities, the sediment supply of the rivers reduced from 10 to 40 %. The Caspian sea level has changed over a range of 3 m during instrumental measurements. The rivers are classified into three groups based on the morphology of their mouths and the nature of river/sea dynamics: Type 1 is rivers that enter to the sea through lagoons and lowlands. They have gained an ephemeral nature due to increasing water consumption recently. Type 2 rivers have a normal flow into the Caspian Sea. They are common in steep slope coasts, where they are rarely affected by human activities and sea level changes. On moderately sloping coasts, they are slightly affected by long-shore currents of the sea. Some distributaries of the rivers enter into the sea independently. Some bars and lagoons are developed in the vicinity of the river's mouth, most commonly since the last sea level rise. Type 3 represents the great rivers with a significant sediment supply (Sefidrud River in the West andGorganrud River in the East), producing deltas and mouth bars. They have high sediment discharge into the sea and are more greatly affected both by human activities and sea level changes.
  • Amin Hosseini Asl, Ali Akbar Matkan, Farideh Javid, Hossein Pourali Page 87
    Remote-sensing and Geographic Information System (GIS) techniques have been utilized in this study to establish a GIS database for Madarsoo watershed in Golestan Province. Among the major constituents of this database we can refer to are: composite multicolor images from LANDSAT TM (30 m resolution); Indian IRS 1C/1D (23.5 and 5.8 m resolution) and Quick Bird (60 cm resolution) satellites and land-use/land-cover maps derived from these images; road networks; soil information; Digital Terrain Model (DTM); slope and aspect information derived from Digital Elevation Model; and meteorological and hydrological data. A 'project office' was established with trained personnel at a provincial centre effectively to use the resultant GIS in planning, monitoring and in applications for flood management, as well as to update it regularly. The approach of geographical data base has the potential to store and manage different data with different formats seamlessly. On the other hand it prevents repeating data, decrease errors, and saves the time and expens. The estaldished data base was applied in mike 11 software to hydrological and hydrolical analysis of flood in the studying area.