Environmental Sciences
Year:2008 | Volume:5 | Issue:4|Papers Count:13

Cities ever-increasing development that has been achieved without getting advantage from natural environment will bring about imbalance condition between urban and natural spaces. River valleys as cities’ ecological elements have always had effective role in creating mutual relation between man-made city spaces and nature. Tehran has special geographical situation as located at the foot of Alborz Mountain. Tehran river valleys originated from Alborz foot in north and continues till south of the city. These river valleys could play important role in pa ving the way for providing fresh water resources, natural corridor of climate flowing, green open spaces, parks, recreational areas, as well as places for public services activities. While investigating the current situation indicates that Tehran وs River valleys not only do not increase the quality of Environment, but also play a negative role in the context. The present article is going to introduce as environmental revitalization plan for the above mentioned river valleys. Velenjak River Valley as the case study, was case studied through field work research and SWOT analyzing approach. Results of the study indicate that ; Determining district for river valley , preventing polluted water (waste water) to be mixed with the river valley و s conservation and expansion of green areas, protecting the open views and perspectives, numerous landscape making, and make it a proper place for various customs, etc…,can play a pivotal role in revitalization of Velenjak River Valley as a vital Environmental, Enter raining, and service corridor in prospering the life quality in Tehran City as one of the most polluted ones in the world.

Eco-Tourism is an unrepeatable element of permanent development. It is a type of tourism that deals with the lovers of nature and is In contrast with the common tourism. In this article I decided to introduce the agreement of this kind of tourism with the current situation in our country; thus its necessity is undeniable, so by mentioning its advantages in tourism, the weak points and disadvantages will be decreased gradually. In order to explain this type of tourism preciously, I introduced some Eco- Tourism backgrounds and defined a comprehensive definition to show the irreplaceable importance of this industry. Furthermore, I attempted to clarify "Why many nowadays pay more attention to Eco-Tourism" and “What is the relationship between Eco- Tourism and globalization, from the upside to the downside of the hierarchy". Then I mentioned the Iranian society’s present condition. I analyzed the recent and common views about tourism in Iran; and by emphasizing on some discourses about identity and the importance of maintaining our values. I decoded some inaccurate presumptions that influenced the substantial revenue, employment ship, and generally many benefits of tourism- in particular, Eco-Tourism. I recognized some prerequisites that should be supposed as protection (Reserved) protecting. Finally, I investigated variable and different dimensions of tourism revolution and very deep changing of technology that reflect the twenty first century’s features. The existence and importance of prerequisites, would provide the usage of Eco-Tourism. When I discussed about the importance of tourism, I pointed out relative and absolute poverty, the number of unemployed people. the group of people who are seeking job and its ratio in the whole population of the country, in order to emphasize on the importance of this industry. At last, I reviewed the key words of the article.

All land use development and particularly industrial development need site selection through environmental capability evaluation and environmental impact assessment to be sustainable. In order to This research analyses Environmental Impact Assessment of Automobile Industry which is going to be implemented in Takestan. Environmental impacts of this development have been assessed using both Rapid Matrix and Map Overlay methods. This process consists of: project description, identification of impact assessing discovering and predicting the impacts of project on environment, impact assessment, presenting the works that should be done in order to reduce negative impacts and present environmental management plan. Results of environmental capability evaluation through comparing with ecological model of industrial development by using Geographical Information System show about 85% of the selected site fits with category 1 and 15% of that fits with category 2, so the suggested place has the required capability for this land use type. In the next step, environmental impacts of establishing such factory were evaluated using Rapid Matrix method. According to the results of evaluation, performing mitigation plans are required. Spatial representation of results obtained through Rapid Matrix show that southern part of the studied area is the most affected. Therefore, mitigation measures and rehabilitation plans in this area has more priority with respect to other places.

Kandovan village which is located at Osco region in East Azarbayjan province named as one of the important tourism and promenade zone of Iran due to its numerous natural places. Studying tourism value of this place could be useful in predicting needs, remove scarcities and development of tourism. The aim of this research is estimating the outdoor recreation value of Kandovan village with the use of contingent valuation method. For investigating effective variables on willingness to pay of individuals, logit model estimated with the use of maximum likelihood approach. Requested data set were obtained by completing questionnaires and interviewing with 180 individuals who visit mentioned village. Results revealed that 83 percents of individuals were ready for paying as a use of the mentioned village. Also, results showed that variables include education, village absorption, revenue and bid had a significant effect on probability of willingness to pay of individuals but variables include age, gender, family size were not statistically significant but had expected signs. Mean willingness to pay for each visitor per year was 3905 RLs and annual outdoor recreation value of Kandovan village was 1171500000 RLs.

Atrazine is the most important triazine herbicides with moderately persistence in soil. The objective of this investigation was to study the degradation of atrazine (50 ppm) in two soils different in texture. Experiment was conducted in completely randomized design with factorial arrangement and 3 replications. Experimental factors included, soil texture (sandy loam and silty clay) and organic manure (0, 2 and 5 percent(w/w)). Soil samples were incubated at 30 oC and dark conditions for 0, 20, 40 and 60 days. At the end of each incubation period, atrazine residue was measured with HPLC. Data was fitted to first order kinetic equation for analysis. Results showed that soil texture and organic manure had significant effects on atrazine degradation rate. Atrazine degradation rate in clay soil with no organic amendment was 1.54 times higher than sandy soil and its half life were 138.6 and 90 days in two soil respectively. Atrazine degradation coefficient increased by 1.14 , 1.8 times in sandy loam soil and by 1.54 , 2.46 times in silty clay soil with 2 percent and 5 percent organic amendment, and the half-life decreased from 138.6, days to 121.57 and 77 days in sandy soil and from 90, days to 58.22 and 38 days in clay soil. It seems that atrazine degredation in silty clay soil is more than sandy loam soil and soil organic manure have an important role in atrazine bioremediation.

Lilium ledebourii (Baker) Boiss.(Liliaceae), locally named “Susan -e Chelcheragh” is an endemic and rare species that grows on the high lands of Damash in Gilan Province, and It is under surveillance of DOE (Department of Environment). Habitat of Chelcheragh lily in Damash is one of the protected areas of Iran's DOE and is placed in Category III (Natural Monument) of IUCN. Lack of information about the biology and specially ecology of this rare plant species is because of severe conservation and limited spatial distribution. In order to determine the ecological needs of Chelcheragh lily or white lily, the habitat of this species in Damash was studied and different ecological resources including: elevation, geographical aspect, slope, soil, vegetation cover, etc. Study of the other habitat in Dorfak (Gilan) was performed based on field investigation and literature review which was in order to determine ecological needs of Chelcheragh lily. Topographic data in geographic information system (GIS) was analyzed and land form characteristics were provided. Results were analyzed (logical) and effective factors on spatial distribution of Chelcheragh lily were introduced.

In order to study the phenology of weeds in the wheat fields and determining suitable indices for predicting phenology events and using the results for improvement chemical control, a trial was conducted in 2006-2007 growting season at Zanjan, Karaj, Varamin and Mahmoud Abad (Mazandaran). The seeds of weeds (Broadleaved and grasses) were gathered in previous season. For satisfied emergence, the weed seeds were treated for breaking dormancy 24 hr before planting. Phenological events of wheat and weeds were recorded during growth season. Thermal time based on growing degree days (GDD) was calculated for each growth stage. Phenological and thermal time results of wheat and weeds compare with the optimum time application of recommended herbicide for weed control of weeds. Integrated results showed that GDD was a suitable index for determining and predicting of wheat and weeds growth stages. Also GDD could use for precision time of application of herbicides and could recommend that 400 GDD and 1200 GDD were minimum and maximum of herbicide application in wheat fields, respectively. Irrigation of field before planting and tillage applicable for control of the weed seeds without dormancy.

Semiotically speaking, the visual environments of cities manifest the societies' socio- cultural and economic values through an intricate system of 'signs'. Acting as an "interface" between man and environment, the visual settings of cities set the ground for environmental perception, cognition and evaluation to be made by citizens and visitors alike. The cities blessed with great visual environments enhance the aesthetic experience of their inhabitants, improve the self- image of the concerned communities as well as their image at the national and international level, and foster the cities competitiveness to attract more economic investment and larger number of creative – class- people. This article aims to explain the significance of the city visual environment, to provide a typology of different notions of "Cityscape, and to model the evolutionary trajectory of the concept of visual environment. In this study, the "urban visual environment" is discussed as a dynamic concept, complying with the evolving nature of urban design discourse, the sustainable development paradigm and the Green (ecological) aesthetics model. The findings indicate that urban visual environment, as a concept, has been subject to fundamental change and modification in parallel to the sophistication process of urban design discourse as a whole. The article concludes the increasingly decline of "Abstract Environmental Aesthetics" and its associated cosmetic approach and highlights the rise of "Ecological Environmental Aesthetics" and its pertaining sustainable approach towards urban visual environment. The study, ultimately suggests a conceptual model to encompass and represent different notions of urban visual environment spanning from cosmetic/ ornamental position right through to ecologically sustainable stand.

Naphthalene is PAHs and is distributed in aquatic and soil ecosystems. Different microorganisms are able to degradate various concentration of naphthalene. Sampling was done from two Noshar and Amirabad harbors. Samples were transferred to Ecological Academy of Caspian Sea and then were cultured in minimal basal medium included naphthalene and trace elements and were incubated in 30°C for 24-72 h. Finally, isolated colonies were identifical as primary and biochemical test. The most important of isolated positive gram bacteria were Bacillus sp, Micrococcus sp and Pediococcus sp. The results showed that concentration of 30 ,40 mM of naphthalene after 312h have been decreased to 9/45 (68/8%) and 3045(91/42%) respectively for Bacillus.

Moving Bed Biofilm Reactor has been taken less attention in treatment of surfactants. In this research with consideration of its advantages and suitable efficiency in industrial wastewater treatment, three 5L-reactors at different retention times were used to investigate the removal efficiency of sodium dodecyle benezene sulfonate (SDBS), sodium dodecyle sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB). The results indicated that the best removal efficiency in batch loading system with filling ratio of 50% of the reactor volume by LECA (Light Expanded Clay Aggregate) was 90, 95, and 93 percent for SDBS (COD=900 mg/l), SDS (COD=1200 mg/l) and CTAB (COD=1200 mg/l), respectively. NMR test results confirmed biodegradation ability of compounds in MBBR. In the study of filling ratio effect in the reactors, the volumes of the carriers were decreased to 30% and the removal efficiency were improved by 2% for SDBS and CTAB systems but no change was observed for SDS system. In the study of temperature effect no considerable change has been observed in the removal efficiency. Finally, biological modeling of the reactors using Stover-Kinkannon, first order and Grau models have shown that the reactors followed both Stover-Kinkannon and Grau ones.

Knowledge of quality and chemical composition of industrial effluent water (EW) for safe and lawful reuses is required. The effect of application of Zob-Ahan (ZA) industrial EW on agricultural land and irrigated grape plants were studied. The compound EW samples were seasonally collected during a twoday period. In addition, the soil and grape plant irrigated with EW were also sampled. Three fields were selected, and in each field soil from 0 to 30 cm, grape plant leaf, and grape samples were collected in three replicates. For each soil, leaf and fruit sample three sub samples were collected and were compounded. Also soil samples of virgin land (control) adjacent each field were collected. In addition the well water in vicinity of EW ponds were sampled seasonally. The results show that the industrial EW COD, TSS, BOD, TDS, NO3-, Cl-, SO4-and heavy metals concentration of Co, Cr, and Cd is limiting for discharge into absorbtion well and irrigation. The available heavy metals concentration of land irrigated with EW were higher than control (Virgin adjacent land) and total heavy metals concentration of land irrigated with EW were in the critical range. The grape leaf Mn concentration was higher than normal range, but grape fruit heavy metals concentration were in normal range. The heavy metal concentration of Fe in all unwashed plant samples were higher than washed ones. Therefore the air pollution and aerosol fall out of Fe is an additional factor to EW application in land and plant contamination in the vicinity of Zob-Ahan industrial complex.

The effect of nitrogen (N) and phosphate (P) concentrations on crude oil biodegradation by two bacterial strains PG01 and PG02, previously isolated from Persian Gulf, was assessed. In order to determine the optimum concentration of N and P sources for oil consumption bye the isolates, bacteria were cultured in mineral salt medium containing crude oil as sole carbon source and with different concentrations of ammonium chloride (N source) and di-sodium hydrogen phosphate (P source). Culture flasks were incubated at 30 degree centigrade agitating 150 rpm for 5 days. Measuring total protein, as an indicator of petroleum biodegradation, revealed that the optimum N and P concentrations for oil consumption by strain PG01 are equal to 0.146 gram ammonium chloride and 0.024 gram di-sodium hydrogen phosphate per gram crude oil. The other strain, PG02, needed more N source for optimum growth and the results were 0.146 gram ammonium chloride and 0.024 gram di-sodium hydrogen phosphate per gram crude oil.