Environmental Sciences
Year:2011 | Volume:8 | Issue:2|Papers Count:13

Exact estimation of evapotranspiration is an important parameter in water cycle, study, design and management of irrigation systems. In this study, the efficiency of intelligent models such as fuzzy rule base, fuzzy regression and Artificial Neural Networks for estimating daily evapotranspiration has been examined and the results are compared to real data measured by lysimeter on the basis of a grass reference crop. Using daily climatic data from Ekbatan station in Hamadan in western Iran, including maximum and minimum temperatures, maximum and minimum relative humidities, wind speed and sunny hours, evapotranspiration was estimated by the aforementioned intelligent models. The predicted evapotranspiration values from fuzzy rule base, fuzzy linear regression and artificial neural network provided root mean square error (RMSE) of 0.72, 0.86 and 0.74 mm/day and determination coefficient (R2) of 0.88, 0.86 and 0.84, respectively. The fuzzy rule base was hence found to be the most appropriate method employed for estimating evapotranspiration.

This article is primarily concerned with the question of how far environmental justice is being and can be achieved within the international legal system. Justice has been conceived since ancient times as comprising not only norms, rules and the institutions by which these are implemented, but also the fundamental principles of fairness and equity both in the implementation of rules (so that one group in society is not unfairly advantaged or disadvantaged) as well as in the rules themselves. Hence, ensuring international environmental justice is not simply a matter of developing and implementing effective standards for the regulation of activities that damage the environment and other means of environmental protection and conservation. It is also important to recognise that the implementation of rules of law may not in itself represent a just outcome and that considerations of equity and fairness then come into play as, for example, in the discretion given to the International Court of Justice under its Statute to decide cases ex aequo et bono. Nationally, governments should seek to ensure that not only do the laws and rules governing the protection of the environment and related matters deal with these questions in a manner that ensures justice equally for all members of society (as far as this is possible) but also that their implementation is fair. On the international level, it is vital that the asymmetry of economic and political power that is the reality of the international community is not expressed as serious injustice with relation to access to, exploitation or enjoyment of environmental resources. As an illustrative case, the question of ‘biopiracy’ of traditional botanical knowledge is considered. This case demonstrates that the existing intellectual property and international trade rules unfairly advantage large corporations over local and indigenous communities and that the system established within the framework of the World Trade Organization and its main Agreements has exacerbated this imbalance of interests.

Phalaris is a grass which is distributed throughout the temperate regions of the world. There are many taxonomic problems in this genus. In order to clarify the taxonomy and the interrelationships among Iranian Phalaris taxa, including Ph. minor, Ph. arundinaceae, Ph. brachystachys and Ph. paradoxa 70 qualitative and quantitative morphological characteristics were examined. Numerical taxonomy was performed on 36 accessions of 5 taxa, concerning intra- and interpopulations variations as well as inter-specific relationships. The most variable morphological characters in the species delimitation were also determined. The species differed significantly in most of chosen qualitative characters. Results show a clear similarity between two varieties of Ph. paradoxa. Despite the wide range of habitats where the accessions were gathered, they showed four definite spots in their PCA ordination graphs. This showed the efficiency of chosen morphological characters in this study. An identification key based on studied features was provided and the species relationships were discussed.

Over the last decades of the twentieth century and early in twenty-first, sustainability has been one of the most prominent discussions in different fields, especially in the field of architecture and urban spaces. It can be balanced through putting the 3 elements economy, environmental and society together. The economic aspect is typically respected because of financial and profit reasons by capitalists, although it is often overly noticed and some problems may arise from that. Environmental subjects also have standards and are noticed differently according to each society. But the social aspect of development is neglected. In the present paper, social sustainability bases including equity justice, aesthetic value, comfort, welfare, children safety and growth, social identity and other similar issues are to be considered. For this purpose, the social sustainability of residential complexes is surveyed by Iranian specialists and social scientists, to record and combine their valuable academic and professional experiences on the one hand, and their experiences of living in a residential complex on the other. Then, through analyzing the resulting ideas, the factors effective on the sustainability bases of residential complexes are extracted. This is a geodesic research of an exploratory geodesic type which is performed on the basis of analysis, description and extraction of questionnaire outcomes and discovery of sustainability bases and relations among them, according to social scientists, in order to determine theoretical sustainability bases of residential complexes. In the next step, through comparing it with external evidence, it would be possible to identify scientific principles and architectural solutions. This purpose will be accomplished through regional research and organizing a questionnaire for such complexes. These matters will come under consideration later.

A pilot scale anaerobic baffled reactor (ABR), for treating low-strength industrial wastewater (671.5±49.9 mg COD/L, 350.1-36.8 mg BOD5/L) was studied. The reactor was started with a hydraulic retention time (HRT) of 25 h and this was gradually reduced to 3.33 h. The best reactor performance was observed with an organic loading rate (OLR) of 4.45 g COD/L.d which was at HRT of 4 h and the COD removal efficiency was obtained up to 78.27% and majority of COD removal was occurred in the first compartment. Under these conditions, for prediction of the effluent substrate concentration (Se) and optimum volume of the ABR (V), the Monod and Kincannon-Stover models were investigated. With using the Kincannon-Stover model, parameters of Umax and KB were obtained 2 and 2.14 g COD/L.d, respectively since, for the Monod model, the parameters of K and KS resulted as 1.54 g COD/g VSS.d and 0.21g COD/L, respectively. The regression line for the plotted linear equation of the Kincannon-Stover model had a R2 of 0.84 which was lower than that found for the Monod model with R2 of 0.985. Meanwhile, in the Monod model, the parameters of Y and Kd were obtained 0.073 g VSS/g COD and -0.008 d-1, respectively. The present study demonstrated that the Monod model is more suitable and applicable for formulating a kinetic model for prediction of the effluent substrate concentration and optimum volume of the ABR at the similar operation conditions.

Column leaching tests become increasingly important for assessing the risk of release of pollutants from soil into water. In this study a column leaching test was designed to provide insight into the fate of selected PAHs in soils and their leaching behavior. Two columns (columns 1 and 2) were prepared based on a standard procedure in which 5 and 20 percent of contaminated soil were used, respectively. The percolates were collected at specified L/S ratios. Results showed relatively high initial concentrations of flourene, fluoranthene and benzo (a) anthracene for column 2. Released amounts of PAH compounds were decreasing with increasing molecular size, or rather the hydrophobicity of the compound. The effect of dissolved organic carbon on PAHs leaching was also investigated in this research. Approximately 2.45% and 0.67% of the total initial amounts of studied PAHs in the soil was leached in columns 1 and 2, respectively. Results showed that high PAHs concentration in the solid phase does not necessarily imply serious groundwater contamination risk during a leaching event (e.g. rain fall) and significant amount of contaminants may stay in the soil layer for a long time and do not leach down into groundwater.

The function of petrochemical wastewater treatment plants should be evaluated intermittently, due to the increase in production and new effluent flow and organic load to the wastewater. In this study, the efficiency of a petrochemical wastewater treatment plant has been evaluated by sampling and determination of major pollutants of wastewater during six months. The results showed that physical, chemical and biological processes used in the plant, succeeded to decrease the COD mean value of wastewater to 80 mgL–1 level. The average overall yields of the total hydrocarbons, volatile organic compounds, phenols and sulfides removal were measured as 77%, 97%, 99.8% and 94.2%, respectively. The majority of volatile organic compounds (88.5%) and sulfides (78.5%) were decreased by stripping and chemical oxidation. The results showed that the existing wastewater treatment plant was successfully assessed to decrease the organic pollutants, while total suspended solids increased slightly during treatment processes although remained within the authorized limit.

Productivity as one of the most important concepts in recent decade applied to improving production. The most common definition of productivity is the ratio of outputs to inputs. Although more precise definitions of productivity have been provided by different authors and organizations in different countries. Agricultural productivity is also measured as the ratio of agricultural outputs to agricultural inputs. Generally, the market value of the final output is a tool for measuring output. Different indices are measured in agricultural productivity including total factor productivity, land index, labor index, machinery index, production index, capital index, etc. In this study 9 productivity indices were measured and analyzed in the agronomy and horticultural sub-sector which is the biggest and the most important sub-sector in the agricultural sector. Data were collected from different Iranian official sources for 11 years from 1992-2001. Also, the data collected were used to explore the trend of different productivity indices in the sub-sector during the studied years. Furthermore, the indices were analyzed and interpreted using advanced statistical methods (principal component analysis).

Despite high growth rates of organic production in Canada, it remains a very small sub-sector of Canadian agriculture. The focus of this paper is on identifying factors that encourage or discourage farmers when considering adopting organic practices, especially the institutional factors that affect the decision whether to convert to organic farming. The data used in the study were collected from a sample of both organic and conventional farmers in Saskatchewan. The results reveal that conventional farmers lack information in many areas of organic practices, and that those institutions related to organic farming are very useful in providing information about organic farming. Lack of knowledge and skills needed to manage an organic farm and lack of market opportunities for organic products are the most important reasons for not using organic farming practices. It appears that conventional farmers’ beliefs and attitudes are important factors in affecting their willingness to accept organic practices. Moreover, the effectiveness and protection of organic regulations, certification bodies and marketers can encourage conventional farmers to convert to organic practices. Conventional farmers' opinions indicate that private organizations in Saskatchewan are important for the development of the organic farming sector.

The fast pace of development of Tehran (a capital city with a population of 12 million and grandiose ideas) over the last 30 years is the major cause of the deterioration of the natural environment and watershed. Stream corridors in the northern part of the city are the major areas for most of the wildlife diversity in Tehran and are easily affected by human intervention. The two major elements of the stream corridors are soil and water. If either of these is affected by human activities the ecosystem will become unhealthy and its natural balance will be unsettled. Therefore special consideration to environmental capacities is essential. This study was conceived on the basis of a phenomenological approach; an extensive literature review on the subject and the case study were also conducted. The research attempts to consider the Evin-Darakeh stream corridor as a green infrastructure by describing the benefits of green infrastructures. In order to reach this goal, planning principles for this stream corridor and the related strategies are explained.

For assessment of water quality in Gharasou River, located in the Northwest of Iran, multivariate statistical analysis was used. During the period of one year, 18 physical, chemical and microbiological parameters were sampled in 11 sampling stations. The measured data were analyzed by a multivariate statistical approach, Cluster Analysis (CA). Based on CA analysis the stations were divided to three groups of highly polluted (HP), moderately polluted (MP), and less polluted (LP) stations. The results of the study revealed that multivariate statistical techniques are an effective statistical method for water quality assessment, identification of pollution sources/factors in water quality for effective water quality management. As Extracted clustered information can be used in reducing the number of sampling sites on the River without missing much information.