فصلنامه محیط شناسی
سال سی و ششم شماره 2 (پیاپی 54، تابستان 1389)

Present survey Studies intensity of heavy metals pollution (Ca, Fe, Ni, Cd, Pb, Zn, AS, Hg) in the sediments of Bamdezh wetland. The main objective of the study is to quantify heavy metal pollution intensity in the wetland. Other objectives of the study are separation of natural and anthropogenic heavy metal pollution and identification of the origin of heavy metals. Results of this study shows Igeo formula values of As, Ni and Pb (respectively 1.52, 1.1 and 1.29) in the Bamdezh sediments that are in the category of very low to moderate, Fe and Zn concentrations (respectively 0.35, and 0.96) are in the category of no pollution, Cd concentration (2.87) is in the category of moderate to high pollution and Hg concentration (6.37) is in the category of very high pollution. Percentage of natural and anthropogenic sections of studied heavy metals shows that Cd and Pb pollution are mostly from anthropogenic origin and Fe, Zn, Ni and also Ca are mostly from natural origin. Result of cluster analysis shows that Pb should have biological origin. Since Ni and Fe are related together by high similarity coefficient therefore it can be concluded that the origin of Ni is anthropogenic. Origin of organic matter in the sediments is not from geological sources and therefore the origin of As and Hg that are highly related to organic matter can not be natural.

Construction and operation of dams have two main effects on streams. At first it increases detention time and then leads to thermal stratification. Changing of water quality is the result of these effects and the outflow has different physical, chemical and biological characteristics from inflow.In this study thermal regime in proposed Bakhtyari reservoir was simulated with CE-QUAL-W2 model. The inputs are reservoir topography, hydrological and meteorological data. As there is no chance to calibrate or verify the model, they will be done in monitoring and operation period. Three different inflow scenarios were simulated based on dry, normal and wet year. Simulation results represent that in dry year stratification starts at April and remains up to September, but the results of normal year indicates that Stratification is between May and November. In wet year because of short detention time, thermal gradient variation is different from dry and normal year and temperature of middle layers imitate inflow water temperature. In all scenarios a stagnant layer could be seen in downward of outlet structure(700mASL).It is concluded that in dry years which dam has a major effect in inflow regime, turnover is mostly conform thermal stratification theories in reservoirs.

In this research, rice husk and activated carbon adsorbents were used for removal of lead ion from aqueous solution at pH= 6. In the batch tests experimental parameters were studied, including contact time and initial metal ions concentration.Survey of the equilibrium time at different concentration showed that equilibrium time is reduced with decrease of initial concentration of solution from 50 mg/l to 1 mg/l for both of the adsorbents, and they are closed to each other. In this state is obtained equilibrium time 45 and 60 min for activated carbon and rice husk, respectively. With the increase of initial concentration of solution from 50 mg/l to 500 mg/l, the equilibrium time is also decreased and they converge. In this condition, is obtained equilibrium time 60 min for activated carbon and rice husk and and are closed to each other. Maximum equilibrium time is obtained 120 and 90 min for rice husk and granular activated carbon adsorbent. Study of the adsorption efficiency at different concentrations indicated that adsorption efficiency is increased with decrease of initial concentration of solution for both the adsorbents, and they are closed to each other. The maximum adsorption efficiency for rice husk and activated carbon at initial concentration of 1 mg/l was found. The attained adsorption efficiency in this concentration was approximately %98 and %99.7 for rice husk and activated carbon adsorbents. In this study, kinetic adsorption models were also studied and Ho et al. (1996) model rather than the lagergren (1898) described data better. Also, fitting langmuir and freunlich adsorption isotherm models on experimental data showed that freundlich model described experimental data better.

Landfill gas is generated by organic waste decomposing under anaerobic conditions. landfill gas contributes to the emission in the atmosphere of greenhouse gases and causing global warming. Humidity of environment is an effective parameter on rate of gas generation in landfills. Saravan landfill is investigated as study area in this research. It located in 20 kilometers of Rasht-Tehran highway. It is modeled as an anaerobic landfill within dry and moist condition in landGEM software and amount of gas emissions in calculated per year. Results of the study show the rate of gas generation in moist condition is 3.85 times of dry condition. In Saravan landfill, the maximum generation rate of methane,carbon dioxide and Non-methane Volatile Organic Compounds (NMVOCs) was 11700, 32110 and 500 Ton/Year in moist condition and 3043, 8349, 130 Ton/Year in dry condition, respectively.In regard to effect of moist on rate of contaminants generation and humidity of the study area, using the cap as a contaminants control methods is assessed. We suggested multiple cap for the landfill. The cap caused oxidation of methane and prevent of moist into landfill, then it reduce the rate of gas and leachate generation. The designed cap has inactive gas collection and leachated drainage systems.

Due to availability of proper materials in landfills (at most parts of Iran especially in Kahrizak) and also less expenditure of this liner in comparison with other liners it can be count as an acceptable choice. Different studies imply that one of the most important factors for soil liner selection is local conditions and also liner compatibility with generated leachate in studied site. Hydraulic behavior of soil liner, which can be condensed in liner permeability, in reaction with municipal solid waste leachate depends on properties of used leachate and liner's soil. This issue is very important, especially in the case of soil with high degree of salinity. Because of this, changes of compacted soil liner permeability were measured by use of Kahrizak landfill soil in contact with leachate in laboratory scale. Permeability test was done based on falling head method and by using of soil samples which was compacted in permeameter and real leachate which sampled from Kahrizak landfill. Result imply that however, liner permeability shows little increase by passing the time but this amount is one or two order of magnitude less than required permeability for liners (1*10-9 m sec-1). So this soil liner has needful competence for controlling of leachate permeation and it can be used as a material creating compacted soil liner according to related standards for Kahrizak landfill.

In addition to ecological values, wetlands provide many goods and services for local communities. Anzali international wetland has always played the same role, but recently, besides degradations caused by population pressure, construction and operation of different infrastructures and developments in its basin, have caused considerable negative impacts on this precious ecosystem. It is obvious that during such developments, besides getting economic benefits, important environmental values of natural resources are irreversibly reduced or destroyed. Therefore, quantifying different values of wetland to economic figures can help decision makers to compare different scenarios and make the correct decision. Due to the fact that a wetland’s non-use values are less involved in decision making, in this research, contingent valuation method is used to determine them. Econometrics methods and Eviews software is used to estimate the maximum willingness to pay according to the offered price. The maximum willingness to pay for an unlimited period of time which is discounted to present rate has been estimated 8803.92 tomans per year.

Anzali porter is one of the cities that is located in Gilan province, is important because it's recreational and tourism attraction in the region. Therefore, the study of recreational value can affect prediction requires, shortage removal and recreation expansion in the region. The purpose of current study is to estimate the recreational value of Anzali wetland with Contingent Valuation Method. Logit Model with Maximum Likelihood method was used for the examination of effective factors on individuals’ willingness to pay. Data was gathered by filling questionnaire and interviews with Anzali wetland visitors. Results show that, coefficients of suggestion price variable, wetland environmental quality, revenue and age was significant in 5% level, but other variables have not significant effect in 5% level to individuals’ willingness to pay. The average of individuals’ willingness to pay for recreation value of Anzali wetland and annual recreational value was counted about 14900 and 1490000000 Rails, respectively. Also, 60% of people have much motivation for cooperation in wetland optimization tasks. Environmental quality variable (pool environmental value) has positive effect on entrance fee. With consideration on the importance of tourism value of attractive environments and in order to achieve healthy and productive society and sustain economic development, it is essential for planners to pay much attention to important environmental quality, control and monitoring to achieve sustainable landscapes these regions and help more for increasing the social welfare with the development of appropriate possibilities and improve hygiene for the families in such places.

Urban facilities are necessary components of cities. In all grown and developed cities of the world there are tremendous network of facilities such as water and electric ties, water sewage drainage, water piping and gas piping. That has not been installed in proper depth underground and locations and with growing of the cities and consumption of population. They need to be replaced by excavating the pavement on the streets which creates practically traffic difficulties and some environmental problems. Current system of urban facilities distribution in Tehran have a lot of loses, the main cause of this, is creating branch without the necessary calculations and obsolescence of networks. Use of utility tunnels started from few decades ago in most European (France, UK, and Switzerland) and American countries. Inside the country accomplished some works about utility tunnels construction from few years ago for example urban utility tunnel construction in district 22 of Tehran. In this research the environmental conditions of investigated area (physicochemical, biological, social- economic) and field studies related to the tunnel constructions, measurement of sound and air pollutants in 6 monitoring station in construction and operation phase have been done. Then by using integrated matrix (Leopold - Saratoga) impacts of the utility tunnel constructions on the environmental parameters were studied. The findings indicated that utility tunnel construction have positive effects on social and economic environment such as job creation and improved(welfare facilities, urban transportation systems, quality of life and landscape), but also have some negative effects on physicochemical environment such as noise, and air pollutions. That negative effects can be decrease by applying proper management.

ISO14001:2004 standard an active and effective element in city management system can improve function of municipality’s environment. It can be constant environment’s management. Despite many benefits of this system in municipality, maintaining is a great part that the function of municipality’s environment dependant on it. In this survey, to design a model for evaluation municipality’s environment’s function in order to keep this standard, multiple criteria’s evaluation was used. In first step, by studding texts and investigations that have done in this aspect and also interviewing with consulters and auditors of ISO14001:2004 standard in certification body, 13 criteria’s evaluation extracted by analyzes the data in software invivo8 and by Analytical Hierarchy Process procedure (AHP) criteria were weighted. The end for preparing a model, weighted linear combination procedure was used. Then by obtained model on 7 regions municipal in Tehran in 1387 that could be achieved ISO14001 Standard certification were done. Results show that the function of this municipality in maintaining this management system isn’t very rich and acting weakly. In this survey, it was proposed for improving environmental function of municipality, keeping of this standard in municipality could be considered.

In this study, we assessed the representativeness of protected areas in Charmahal & Bakhtiari province, Iran, in terms of vegetation types and endemic plants species as biodiversity surrogates. We applied "systematic conservation planning" procedure as our method. The conservation target for each vegetation types was determined based on their natural rarity and threats. One representation in existing and/or planned protected areas was also considered as endemic/rare plants species conservation targets. 7.43% of the study area is officially under protection; however 19 vegetation types out of 36 and 33 endemic/rare plants species out of 52 are not represented in the existing protected areas. Meanwhile, 14 endemic/rare species were represented only once and 12 vegetation types less than established targets. Representativeness of existing protected areas network can improve by adding new areas in an appropriate spatial configuration from forest types located in Bazoft valley and also Kallar mounts for covering rare plants species. The total area needed to meet the entire targets for all vegetation types was 15.61% of the study area which approximately was two times of the existing protected areas (7.43%) and a little more than statutory and planned protected areas together (14.76%).

The logistic regression (LR) method, as an empirical estimation method, was used to model urban growth in Gorgan city between the years 1987-2001. Three groups of variables including Social-economic, land use and biophysical variables were used. Similarity among variables is probable. To remove the correlated variables, covariance was calculated and distance to administrative, sporting centers and cities, with covariance greater than 0.9, were deleted from the group of independent variables. Relative operating characteristic (ROC), was used to assess success of modeling approaches and to assess the model sensitivity for independent variables remove. ROC value for the LR with full data was 0.87. Using probability image of urban growth predicted by the LR model, which shows likelihood for land use change to urban use in future; urban distribution patterns for the years 2010, 2020, 2030 and 2040 were created. New urban location is selected from the cells with the most likelihood for land use change. Also, the relative effect of the 10 predictor variables were evaluated through ROC using 10 reduced-variable models and the full model. Cultivated areas and pasture were the most influential variables in comparison with the others in driving urban growth. This shows that present land use has the most important rule in urban growth in Gorgan city.

Ineffective transport system in large cities including Tehran, creates important environmental problems such as increases in fuel consumption resulting in loss of large amounts of non renewal natural resources.The increasing of oil consumption in Tehran city is mostly for the inefficiency of transportation systems. This problem is one of the main causes of destruction and ending of environmental resources. The main aim of this research is to determine the optimum portion use of various transportation systems to decrease oil consumption and environmental degradation. For this aim the oil consumption of each transportation system per each traveler and the equal land area to produce that amounts of oil are calculated and analysis by ecological footprint method. The results of analysis show that subway with. 003 m2 land per each traveler has the least oil consumption which is equal to 1400 private car traveler as the highest oil consumption. That means. 071 private car traveler could be the best distribution of transportation systems per each subway traveler. Considering this rate and forecasting of population for the year 1405, the optimum scenario for the least oil consumption has been determined.

Takab-e Afshar in the north – west of Iran. It is in a mountainous area near the cities of Dandi in Zanjan, and Takab in west Azerbaijan, lies a complex of historical and natural properties among which stands the world heritage properties of Takht-e soleyman with all its features. The present protective buffers for this site have been defined without considering the natural and cultural landscape that are the major criteria having unique roles in their development. In this study, modern technologies like satellite data processing and image analysis have been applied besides field studies and environmental interpretations together with different scientific data such as geology, botany, hydrology, hydrogeology, Tectonic, and etc. Studying the historical, natural and cultural context and consistency of Takab-e Afshar region can lead to identifying a more suitable protective margin for integrated conservation of Takht-e soleyman cultural landscape as a unified concept and also prevent its destruction.