Journal of Environmental Studies
Year:2007 | Volume:33 | Issue:43|Papers Count:19

Increasing urbanization and growing population density with their ensuing enhanced transportation cause problems in the bioconditions of the urban environment. Heavy metals such as lead and cadmium account for part of the environmental pollution resulting from urban transportation. The purpose of this study is to determine lead and cadmium concentrations and their distribution trend in urban roadside soil. For the purposes of this study, four roadside sites were selected in Isfahan. Samples were collected from surface soil (0-5 cm) and deep soil (50-55 cm) at distances 0.5 to 50 meters from the roads. The results from statistical analysis of lead and cadmium concentrations demonstrated that roadside soils were polluted with heavy metals as they exceeded maximum acceptable concentrations (MAC) of agricultural soils. It was observed that lead and cadmium concentrations in soil decreased nonlinearly with increased distance from road at each site. Regression analysis of data from lead and cadmium normalized concentrations (as the dependent variables) versus distance from road (as the independent variable) showed that the logarithmic regression model, in terms of its simplicity and its relative fitness to all the data from this study, could be adequately used as a suitable model for the distribution of these metals in roadside soils. The results obtained from this study can be used in designing urban areas and in planning urban transportation management and traffic control system.

Extreme climate events (droughts, floods, heat waves) are those that are rare both in their intensity and in the frequency of their occurrence. Changes in the occurrence of extreme events can often have far greater detrimental impacts of ecosystems and human societies than a change in average climate conditions. Damage resulting from extreme weather events in Iran already imposes a heavy toll on society that few economics are easily able to absorb. In this study the reliability and behavior of extreme events in Iran by using extreme climate indices software (ECIS) was investigated. The indices were selected from the list of climate change indices recommended by the CLIVAR. The findings revealed that the cold extreme indices such as FD& ID have significant decreasing trends In addition warm extremes indices such as T40, SU show pronounced increasing. Trend of Indices of extremes precipitation such as WD, is increasing. Analyses of the return periods of cold extreme such as FD& ID show the return periods were long and warm extremes were shorter.

The main goal of this research was classification of ecological groups and investigation of its relation with plants biodiversity indices in Afratakhteh reserved area. This study was conducted based on Brown- Blanquet method. At first homogen vegetation units were identified and then 41 sample plot (Releves) were selected selectively. The study of biodiversity indices was performed based on species covers data and use of current formula including Simpson and Shannon- Wiener. For ecological groups classification and ordination, Two way indicator species analysis (TWINSPAN) and Canonical Correspondence Analysis (CCA) were performed respectively using Pc- ord for win 4.17 software. Four ecological groups were distinguished on the basis of presence-absence and cover of plant species. Then the relationship between releves distribution and biodiversity indices was investigated using CCA. The results showed that ecological groups are exactly different together in species composition, biodiversity and physiography variables including elevation (A. S. L.), slope and geographic aspects. Result showed that the diversity and richness were decreased with increase of elevation and slope that causes more difficult life conditions.

Application of statistical techniques in applied sciences, especially in climatology and meteorology, are widespread and a common practice. This paper deals with the application of modern techniques such as kriging, co-kriging, and inverse distance weighted for prediction of rainfall in places where there are not gauging facilities. The available data from all stations throughout the country, since their establishment to 2004, have been used to find the variogram and cross-variogram. Based on the best possible model, rainfall map for the country has been prepared.

Noise pollution is one of the most important environmental pollutants, which has different effects on human life. This research is about noise pollution produced by vehicles in Yazd City, as well as comparison of the results with Iranian standards. The effects of noise pollution in creation of different health problems such as concentration disruption, affect on conversation, effect on sleeping, stress, headache, dizzy, fatigue, weakness of mussels was another point to be clarified to complete this research a questionnaire was used to ask people about their health condition and its relationship with noise pollution. The people used in this research are divided to four different groups working in different areas of the city Yazd; including Yazd university employees, business people working in crowded streets and business people working in non crowded streets and the police officers .In total 200 people filled out the questionnaire for this investigation. After collection of the questionnaire and analysis of the results, it became clear that the difference between the groups is significant at the level of %5 in depressing and total mark. The group of people who are affected at the highest level is the police officers. In contrast the effects of noise pollution on Yazd University employees are the lowest between four investigated groups. Finally, it should be added that the level of noise pollution in total areas was higher than Iranian standards. Also in this research we found out that motorcycles are most suffering vehicles in terms of noise pollution in Yazd.

In this study zoning for management plan of Dorfak Non-Hunting Area (37899 ha. North of Iran) has been implemented. First ecological and socio-economic resources were surveyed and mapped (scale 1:25000). Then data analysis and integration using Arc info workstation (ver.9) and arc view GIS (Ver.3.3) with system analysis approach were performed. As a result 8817 micro-ecosystem were mapped. Ecological capability of Mapping Unit (MU) was evaluated for: restricted nature reserve, protected, area, extensive use, intensive use, recovery, and Special use, culture-historical and domestic zones, with the aid of specified ecological park management model. Finally with coordination of socio-economic data and ecological capability of MU, priority, ranking and arrangements of zones were mapped. The results show that %23.6 of allocated zones is suitable for restricted nature reserve zone, %.5 for conditional strict nature reserve, %45.2 for protected area zone, %.3 for protected and historical zone, %8.7 for protected and recovery zone, %5 for recovery zone, %.04 for Intensive use zone, %8.8 for Extensive use zone, %0.11 for domestic use zone, %0.38 for culture-historical zone and %5.69 for buffer zone (with protected area & rehabilitation zones).

Cupressus arizonica is one of the most important species for forest plantation in degraded ecosystems and dry and semi-dry shrub-lands in Iran. It is an important species for urban green space. In this research the effect of various shading treatments were considered on seedlings first growing season height growth. A complete randomized design with four replications was performed. At first 24 quadrates including 24 seedlings in each quadrate (in total 576 seedlings) were indicated. Six different light treatments including 0, 33%, 50%, 67% and 100% and one treatment including the seedlings under Walnut trees canopy (%75 cover) with four replications were performed. Seedlings heights were recorded in 9 times. The results showed that maximum seedlings height growth ratio (%40.6) was occurred until July. Maximum seedlings height growth and minimum seedlings height growth and mortality respectively occurred under walnut canopy and full light treatments. Such increments were not significant in next months of the period of study. Final seedlings height in artificial shade treatments was greater than full light treatment. Generally, the results proposed that using %33 full light treatment (% 67 projected shades) and special tending practices in July and August of the first growing season to enhance Cupressus arizonica one-year-old seedlings in the study area and similar districts.

Using factor analysis and cluster analysis for hydro geochemical analysis of Gorgan water sources, the related data of two sampling periods in spring and winter is used. According to correlation matrix, in spring and winter, Po4-3, HCo3- and K+ much of the groundwater is correlated with electrical conductivity. Cl- has more combination with Mg-2 in spring, while there is the most combination between the Ca+2 and So4-2 in winter. The cluster diagrams show that there is similarity between Cl ions and Mg-2 in groundwater more than 88%, and 80% between So4-2 and Ca+2 ions in spring while there are the most similarity between So4-2 and Ca+2 in winter, and then Cl- and Mg-2, according to this and correlation matrix, the dominated type of groundwater is Mg-2- Cl- in spring and is Ca+2- So4-2 in winter. According to the analysis method, three factors which are effective on chemical combination of groundwater include: 1- Aquifer hydro geochemical Process, because most of the cations and onions have factor-load in high level. 2-Feeding by surface water (river, runoff) because of increase of HCo3-, s concentration and ground waters Po4-3. 3- Human activity (seepage of wastewater, absorbing wells and …) because nitrate is showing the highest load in third factor. The nitrates concentration in groundwater is more influenced by wastewater and irrigation of agriculture fertilizers. In the third factor, the concentrations of Na+ and Cl- are considerably increased.

The concern about the long-term effects of heavy metals as the environmental pollutants has been increased greatly. It is assumed that biological monitoring can be a satisfactory way to measure the level of heavy metals and their bioavailability. Because of difficulties of detecting biological effects in the habitats, it is more logical to measure the amount of pollutants in the organisms. It is stated that fish eating birds due to being located in high-trophy levels in ecosystems and being highly sensitive to toxic substances, are considered appropriate bio indicators for heavy metal pollutions. Therefore, to fulfill the requirements of the Survey phase of the ecotoxicological classification, a study was conducted to determine the level of Cd, Zn, Fe, Cu & Cr in the liver, kidney and pectoral muscle of great cormorant (Phalacrocorax carbo) in Anzali wetland in 2004.Statistical tests results indicate that concentration of Cd in adults' livers were significantly higher than the immature(p= 0.05), which can be related to their long term exposure to low concentrated Cd. Zn (p= 0.05) and Fe (p= 0.01) amounts in the females' muscle and Cr amounts in the males' kidneys were significantly higher (a= 0.01). Also, the mean concentration of Cd, Cr in all three organs was lower in comparison with global proposed levels for waterfowls. However, high level of Cr and Cd in some samples implies that those birds may be exposed to them in their habitat. Fe, Zn and Cu contents in some organs were higher than the suggested figures. Generally, different human activities around the wetland and also sewage discharge can be considered as the main source of pollution and they may be affective factors in increasing the metal contents. Therefore, finding the main sources of pollutants adjacent to the wetland is very important. The results of this study can be used in consistent monitoring of heavy metals in P. carbo in Anzali wetland.

The current research was carried out in Patom, Nam Khaneh, Gorazbon and Chelir Districts in Experimental and Educational Forest of Kheyroud. Thanks to extent of study area and dispersion of Wych elm on this area, the plot less sampling method was applied. After field inspection and identifying the remaining individuals of Wych elm trees (Ulmus glabra), ³d.b.h 10cm, Physiographic Factors (altitude a.s.l, aspect, slope were recorded. The results that Wych elm trees were distributed from 330 m to 1315 m above sea level. On north-facing and east-facing slopes, the numbers of elm trees were the most and least, respectively. In relation to slope or steepness, this tree dispersed on plain or flat terrain to steep slopes but the number of tree in gentle slope was more than higher slope.

In this study, the woody plants biodiversity and regeneration are compared in two Fagetum and Carpino-Fagetum associations in Namkhaneh district, the second district of Kheyroodkenar searching, and investigatory forest. Sampling was done by systematic randomly method by 200*200m network in 250hec of land area (125 hectares in each associations) in 60 sample plots (5 micro plots (3*3m) within any sample plots of land). Whole woody plant was numerated in (3*3m) micro plots. The results of this research show that the Fagetum association has more variety and richness than the Carpino-Fagetum association. The effect of evenness indices compared to richness is more to increase biodiversity. The high rate of marking plants, especially Horn beam, in prefer of Beech Trees has caused to decreased biodiversity in Carpino- Fagetum association. Number of seedlings of Fagetum association is more than it in Carpino- Fagetum association, but number of yearling and sapling are on the contrary.

Multitemporal images acquired by Land sat 4, 5 and 7 TM and ETM+ sensors on June 30 1989, August 18 1998 and August 2 2001 have been used to study and monitor the relationship between temporal dynamics of LST in relation to Land use/cover characteristics in Tabriz metropolitan area. The classification of images and extraction of statistics of each class showed a strong relationship between land use type and surface temperature using correlation analysis and multivariate regression showed the efficiency of vegetation cover in mitigating surface temperature. Temporal variability of thermal data and vegetation cover has been studied using normalized Fr/T* space. Temporal trajectory of pixels in the mentioned space showed that the changes due to urbanization could be observed as pixel migration from comfort state ( low temperature , dense vegetation) to uncomforted one ( high temperature, sparse vegetation) in the Fr/T* space. The results show that the adopted method is efficient and could be used to study and monitor temporal and spatial changes of UHI in built-up areas.

Environment as a complex system consists of elements formed and changed throughout the time in accordance with its structure and development characteristics. These changes led to gradual transformation of the physical elements of environment; and consequently have shaped and caused the new environmental landscape. Characteristics of these changes can be studied in a meaningful way through understanding environmental patterns; within which influential causes and factors will be identified and analyzed. This paper therefore, aims to investigate and analyze the landscape and environmental changes in the Daarabad Valley- Tehran in the forty five years (1956-2001) period. With its considerable role and implication in the analysis of complex systems, the Chaos theory was used as new approach to develop a theoretical framework for analyzing Daarabad valley's environmental changes. Image Classification and Texture Analysis are recognized as useful techniques in the process of tracking environmental and landscape changes in recent decades. Therefore, the Daarabad valley aerial photographs were used and analyzed through IMAGE PROCESSIN method. Through a mathematical algorithm based on GABOR filter in MATLAB environment. This provided a medium for the Pattern Recognition and analysis of environmental changes in the area. Research findings of this paper demonstrate that characteristics of landscape and environmental elements such as floral pattern (plants covering, native plants, and gardens), city form and open space are changing continuously during the time. Therefore, growth or change of these patterns are generally unpredictable; even tough, to some extent a fractal pattern of development might be observed. This might suggest considering the concept of uncertainty as a major issue in the field of environmental design and urban/regional planning.

Research and studies on the natural archeological site of Pasargade, a world heritage, have mainly been directed towards archeological excavations and discovery of remnants. Its natural features, including the ancient lake of Pasargade remain in a veil of ambiguity. Determining the exact location of the ancient lake and the course of Polwar- Seivand River are valuable criteria in verifying the boundaries of Pasargade, and important factors in the formation of this valuable site. The objective of this study is thus, determination of possible existence of the ancient lake in the Marghab plain, and if proved, verifying the exact location of the lake basin. The research method consists of processing aerial photos and satellite data, using historical and archeological documents, and field studies. These methods helped provide the natural bed layers of the site comprising of geological, geomorphologic, hydro-geological, vegetative cover and climatic features. The research led to discovery of an ancient lake basin in the mouth of Bolaghi Gorge, and determination of the river course across the plain in the Akaemenian era. After proving the existence of a lake and the natural bed features of the site in the Akaemenian era, the next question was brought up: Have the lake and river had any effect on the formation of Pasargade site, and the organization and distribution of its buildings? A second analysis of data, revealed the direct effect of the existence of lake and river on the spatial and structural relations of the scattered structures in the site, including the castles, ancient riverbed, Pasargade gardens, tomb, and especially the entrance to the palace.