نشریه علوم محیطی
سال هشتم شماره 3 (پیاپی 31، بهار 1390)

Rapid urban growth and industrialization have caused many environmental problems in a number of cities around the world. Knowledge about land cover/land use changes in the long term is very important for urban managers and policy makers in order to evaluate and predict the resulting problems. Remote sensing is an effective tool for monitoring these changes in urban areas and its periphery. Over recent decades، Yasouj City has developed and affected its surrounding environment due to urban growth and immigration. The objective of this research is to develop a Decision Tree and data mining based conceptual model for land cover change detection using a Landsat Thematic Mapper (TM) and ancillary data in the central Section of Boyerahmad County from 1990 to 2009. Based on findings of the study، the overall six-class classification accuracies for 1990 and 2009 were، respectively، 93. 16% and 93. 37%. The overall accuracy of land cover change maps، generated from post-classification change detection methods and evaluated using two approaches، ranged from 85. 6% to 86. 98%. The maps also showed that between 1990 and 2009 the urban area increased by approximately 19. 28% while agriculture and forest decreased by 31. 76% and 7. 32% respectively.

Nowadays، environmental minerals represent one of the most important problems in coal mine and coal cleaning factory contamination. Zirab coal cleaning factory in Mazandaran Province is one of the largest and the oldest in the coal concentration of the Central Alborz Coal Basin. So، annually، a huge amount of coal tailing will be left. The sampling of environmental secondary surface minerals، drainage water from coal tailing،the factory''s waste water، and river water have been carried out. Hydrogeochemical studies demonstrate that drainage and seepage water from tail dumps are of the (Na-Ca-Mg) -SO4 type. Gibbs diagram indicates that lithology is the most important factor in increasing the ionic concentration in drained and seepage water from tailing and river water. In arid seasons due to the evaporation of hydro-sulfate solution، blodite and secondary minerals are formed on the tailing dump surfaces. This drainage water from tailing and Zirab coal cleaning factory into the adjacent river has caused the precipitation of hematite، calcite and amorphous iron oxide. Hydrogeochemical modeling has shown that hematite goethite and iron hydroxides along with carbonate minerals (calcite، dolomite and aragonite) are present. The rate of SO4، PO4، Ca، Sr، Sb، and Bi in seepage water from tailing and coal cleaning factory are higher than the standard values، which can cause both surface and groundwater pollution in this region.

This paper examined factors influencing potential demand of farmers’ credit to tendency for producing greenhouse organic cucumber in Khorasan Razavi province using linear regression and cross sectional data of 60 greenhouse cucumber producers in 2008. Data were collected using a questionnaire and census method. Results showed that the financial ability to investment in producing greenhouse organic cucumber required credit for the adoption of greenhouse organic cucumber production and the interest rates on offer are 30 million rials، 328 million rials (at a greenhouse level with an average area about 2700m2 and 4. 82 percent، respectively). Evaluation of farmers'' attitude showed that 66. 7، 66. 7، 86. 7 and 53. 3 percent of farmers will invest the credit in purchasing organic fertilizer، purchasing biological control services، creation a suitable organic agronomic environment and the purchase of mechanical control services، respectively. Also، the relationship between the farmers'' job، agricultural advisory، agricultural experience، organic market information، financial ability to invest in organic cucumber and potential demand of credit for producing greenhouse organic cucumber is negative. The relationship between the age of farmers، cucumber insurance، average yield of conventional cucumber، information about organic cucumber، cultivated area allocated to organic cucumber، interest rate offered، participation in extension classes and potential demand of credit for producing greenhouse organic cucumber is positive. Regard to the results، the following are suggested: creating an organic products market information system، encouraging farmers to full-time farming، promotion of farmers’ revenues towards increasing their financial ability for investment، use of agricultural supervision، promotion of their role in producing greenhouse products and orienting insurance towards effectiveness in decreasing of risk and increasing production.

Kordasht، a village of Jolfa located in East Azerbaijan Province، has become one of the greatest recreational places in the province though having many attractions. Therefore، studying its recreational value can be effective in anticipating needs، removing shortages and in the development of tourism in the district. The aim of the current research is to estimate the recreational value of Kordasht village using the Contingent Valuation Method (CVM). A Logit Model was estimated using Maximum Likelihood Approach in order to investigate the effective factors on individual willingness to pay. The required data were collected through completing questionnaires and oral interviews with 180 visitors. Results showed that 83% of visitors are willing to pay some money to visit the village. Also، variables that included level of education، village attraction، income and prices offered (bid) had a significant effect on the probability of anticipated willingness to pay، whereas other variables such as age، gender and family size were not statistically significant. Visitors'' expected willingness to pay was set at 2800 RLs and the recreational annual value of the village was estimated to be 280 million RLs. According to findings، there is the possibility to increase tourism revenue by considering the visitors'' point of view.

The regeneration structure and biodiversity of trees and shrub species in the understory of pure and mixed oak plantations were investigated at Chamestan Forest and Rangeland research station. Planted species included oak (as the main species) and maple and nettle trees (as associated species). These species were planted in 1995 on the basis of a split plot design with two mixtures (oak-maple and oak-nettle tree) and four mixing rates (including oak rate: 40 %، 50 %، 60 % and 70 %). All the seedlings and saplings of woody plants were divided into two height classes including 15-200 cm and more than 200 cm. In the biodiversity study، the Berger-Parker dominance index، Fisher alpha diversity index، Margalef richness index and Equitability J evenness index were used. The results showed that the abundance and diversity of regenerated species in the understory of mixed plantations of oak-nettle tree was greater than in a pure stand of oak and a mixed oak-maple stand. Crown cover and litter layer depth showed a negative significant effect on their abundance and richness. The presence of primary forest species in the understories of mixed plantationa showed the usage of these plantations in the development of succession in natural forests.

Phytoremediation is a technology for extracting or inactivating pollutants. In this study، the ability of Glycyrrhiza glabra (var. glabra and var. glandulifera) for phytoremediation، tolerance to cadmium and accumulation of it within plant was investigated. The seeds of G. glabra var. glabra and var. glandulifera were cultured in pots and were watered with distilled water (control) and 100 & 200 µM cadmium chloride solution (treatment). Then the plants were analyzed after 20 days. Cadmium causes a decrease in seed germination. The dry weight of root in both variety and the length of root in var. glandulifera decreases significantly in proportion to the control group. Whereas، the dry and fresh weight of shoot، the length of shoot and the fresh weight of root in both variety and the length of root in var. glabra didn’t change significantly. No metal-toxicity symptoms such as burning and redness of the tissue were observed in Cd treatment. Plants containing more than 100 mg. kg-1 of Cd in dry shoot tissues should be considered as hyperaccumulators of this metal. Cd concentrations in the aerial organs of var. glabra and var. glandulifera were 116. 9-147. 9 and 116/0-119. 5 mg. kg-1 (on a dry weight basis)، respectively. We conclude that plantlet of G. glabra is a hyperaccumulator of Cd. G. glabra and so shows promise in the phytoremediation of Cd from polluted sites.

The temporal and accurate change detection of earth surface features is extremely important for understanding the relationships and interaction between human and natural phenomena in order to promote better decision making. Remote sensing data are primary sources extensively used for environmental change detection in recent decades. In this study، images of landsat (TM) 1988 and landsat (ETM+) 2001 were analyzed using five change detection techniques over 80،470 hectares in the region of Daresher in Ilam Province. Change detection techniques considered were image differencing، image ratioing، NDVI differencing، change vector analysis (CVA) and post-classification comparison. In this study، a statistical method was used for determining the change threshold. According to the results، the threshold level was set at ±1 standard deviation from the mean. After determining optimal threshold، areas having decreasing، increasing change and no changes was determined. Based on ground data، field visit and Google Earth، accuracy assessment of change detection techniques was carried out using overall accuracy and Kappa coefficient. According to the results، NDVI differencing with an overall accuracy of 98. 5 and a Kappa coefficient of 97% showed the highest accuracy among the techniques applied while، in contrast، band ratioing with an overall accuracy of 72. 5 and a Kappa coefficient of 50% had the lowest accuracy in land use/land cover change in the study area.

Lead and copper are heavy metals that are applied in different industries. Their standard limits in drinking water are 0. 05 and 1. 3 mg/L، respectively. Since natural absorbents are inexpensive and may be achieved without any cost and they are usually found in abundance in nature، absorption of solute ions by these materials is a proper method for eliminating heavy metals from polluted waters and industrial wastewaters. In this study، tea leaves and wheat straw wastes were used to absorb lead while sawdust and rice hull were applied to absorb copper from a polluted solution under batch and continuous conditions. The experiments have been carried out at different concentrations and times with an optimum pH of 5 and 5. 5 for lead and copper، respectively. According to the batch experimental results، the equilibrium time has been found to be within the range of two hours. By increasing the concentration of absorbed material، the absorption efficiency has been diminished. The results of the batch experiments coincided with Langmuir and Freundlich isotherms but did not agree with BET and Linear isotherms. Continuous experiments have been accomplished with the use of an absorption column and a high up-flow rate of 0. 35 L/min. In general، absorption efficiency has a decreasing trend over time. Based on the results of the continuous column system، the percentage maximum sorption of lead for tea leaves and wheat straw wastes came to be 99. 5. This value for copper by sawdust and rice husk was found to be 95 and 63 percent، respectively.

Continuous and disperse blanks in most hydrological data (e. g. rainfall data) often occur due to data loss، elimination of incorrect data and the malfunctioning of measuring instruments; these then need to be estimated and/or evaluated for subsequent analysis. There are various methods available for estimating and regenerating these data، the accuracy of which depends very much on the specific conditions of the station، so that one specific method may suit a particular station. Generally، data from four adjacent stations are used for regenerating the missing data at a particular station. In this research، fuzzy regression efficiency is employed for reconstructing yearly rainfall data in Karoon basin. The results are compared with methods such as normal ratio، graphical، simple linear regression and multivariate linear regression. Reconstruction groups were formed using the clustering method in minitab software. Twenty-five stations، similar in their duration of data collection، were selected from among stations in the northern Karoon basin and these were classified into 5 clusters. Following data elimination by cross validation، their value was estimated using the above mentioned methods. Then، using the root mean square of errors (RMSE)، the priority was evaluated for each method. The results of yearly data regeneration indicate that fuzzy regression yielded more accurate estimates in 12 out of the 25 stations studied، or in 3 clusters out of the 5 classified group، making it the most appropriate method for regenerating data for the whole of Karoon basin.

In this paper، a simple methodology based on multivariate analysis is developed to create a groundwater quality index (GWQI). The methodology is based on three general stages، selection، standardization and aggregation، to develop a groundwater quality index in an area using regional and local standards. In this method، through selecting a set of similar parameters، standard values of the parameters are obtained by dividing the averaged concentration of parameters by their maximum allowable concentration cited in Iran’s Water Quality Standard. Final indices for ground water quality are derived through weighting the standard magnitudes of the parameters. In order to appraise the approach، existing water quality data for the ground water of the Qazvin plateau were used. In the selection phase، eight important parameters (K+، Na+، Ca2+، Mg2+، SO2-4، Cl-، TDS، pH) for the potability of ground water were selected. These parameters were more accurately monitored and documented in the study area and are very important in desirable drinking water. In order to identify the suitable range of indices، the derived indices were compared with those obtained for some mineral waters. Sketching a comparative ground water iso-index map in the study area makes it possible to have a comprehensive and easily interpretable picture of the ground water quality in the area of Qazvin plateau. Results show the proximity of the derived indices to those obtained for mineral water in some regions of Qazvin Province. It is clear that evaluating the overall suitability of the ground water for drinking usage in an area essentially needs survey of other parameters in addition to those observed here.

In the thinking of neoliberal institutionalism، international organizations are capable of increased collaboration between national governments in global issues and to act independently of the wishes of superpowers on the international scene. This research has attempted to test the gains made under the neoliberal doctrine، associated with the role played by international environmental organizations in the challenges of economic relations of North-South، through the «analysis of competing hypotheses» method. For this purpose، two other hypotheses were developed to compete with the main hypothesis showing the interests of both North and South countries with regard to international organizations. Among the various efforts of the United Nations as the largest international organization active in the environmental arena، five important diplomatic meetings – namely، Stockholm، Rio، Kyoto، Johannesburg and Copenhagen – were selected and judged on the basis of each of the competing hypotheses. The findings of this study show that international organizations have been continuing the policy of capitalist countries in the economic relations between North and South، rather than promoting environmental concerns. The interests of countries of the South have been the lowest of their priorities.

Petrochemical Industries are potentially capable of having impacts on environment due to the nature of these activities and the production of waste water، pollutant gaseous emissions and hazardous wastes. This case study has considered the adverse environmental impacts of petrochemical industries on existing habitats in Mahshahr Special Economic Zone with respect to the regionally significant biological diversity and ecologically valuable species. When results from regional estuary biological and physio–chemical quality sampling as well as of impacts from petrochemical industry pollutants has been analyzed and studied، the affected ecosystems have been ranked using the Analytic Hierarchy Process method، Expert Choice software and the Eigenvector technique. The study’s outcomes show that، with respect to the essence of petrochemical industry pollutants in the region، specifically waste waters including heavy metals، oil and grease، COD، TSS، along with principal standards، criteria defined in the AHP method (such as ecological value، protecting value and exposure)، estuaries represent the most affected ecosystems in the region. On the other hand، different types of fish and benthic، such as Decapods، Gastropods and Tanaida have been highly affected by the consequences of the petrochemical industry’s activities. It is concluded that deposits of heavy metals، oil and grease into the environment are the most important sources of pollution for the regional estuaries and these should be controlled.