جستجوی مقالات مرتبط با کلیدواژه « گرمایش جهانی » در نشریات گروه « عمران »

In recent decades, population growth, increasing urban development, and polluting industries have led to an increase in the production of greenhouse gases and the phenomenon of global warming in various regions of the world. Asphalt pavements, as the main infrastructure of the road transportation system, may suffer failures with high repair costs due to their rheological properties under the influence of this phenomenon. In this study, the Prophet model was used to predict the temperature for the years 1400 to 1421 in three 7-year periods under three optimistic, intermediate, and pessimistic scenarios. The prediction accuracy of this model based on the fitting coefficient was more than R2=0.8 on average. Based on the prediction, the country's demand for bitumen with different functional classifications is then presented in comparison with the available quantities. By predicting and calculating the functional classification of bitumen in 1440 and presenting the results at two confidence levels of 50% and 98% for 34 meteorological stations in the 31 provinces of Iran, a long-term overview of the temperature situation and the required functional classification of bitumen based on the meteorological information of each station is also provided. The increase in the average temperature of the studied stations at the end of the 21-year period was 0.73 and 1.094 degrees of centigrade at a confidence level of 50% and 98%, respectively. According to these results, most of the studied areas will experience a significant temperature increase in the coming years, and this phenomenon will increase the high and low temperatures of bitumen performance, which will require the use of PG76-10 and PG82-10 bitumen. The increase in high and low performance temperatures will require the use of alternative bitumens and the use of appropriate bitumen additives for all climatic conditions.

Climate change has caused changes in the frequency and magnitude of heavy rainfall, which affects the design standards of some hydrological structures (Yousef and Taha, 2015). Rainfall intensity-duration-frequency (IDF) curves are a standard tool for hydrological risk analysis and design (Mohymont, 2004; Veneziano, 2002). IDF curves show useful information about the occurrence of floods in an area and that in the future a certain amount of rainfall or a certain volume of flow will return again (Basumatary and Sil, 2018). Because the trend of severe rainfall events is expected to change in the future, this affects IDF curves, so these curves need to be updated (Srivastav et al. 2014). The need for such an understanding stems from the fact that existing drainage systems are designed to deal with past rainfall events and may not be sufficient to compensate for future rainfall characteristics (Shrestha et al. 2017). In developing countries such as Iran, the large country area as well as the shortage of rain gauge stations and/or the statistical period of the recorded data, makes it difficult to estimate IDF curves (Zamani Nouri, 2011).

Nowadays, the phenomenon of global warming due to the emission of greenhouse gases by mankind is seen as an important environmental concern that endangers future prosperity. Carbon dioxide gas has the greatest impact on the global warming phenomenon among greenhouse gases in the atmosphere. Increasing greenhouse gas emissions, including carbon dioxide, results in global warming, rising sea levels and occurrence of biologic changes in the environment, subsequently it leads to the damage to plants, animals and ecosystems. In the present study, the approximate amount of carbon dioxide generated by industries in the industrial town was estimated, and then the amount of green space needed for its control and management is calculated, so in this regard, the information of 39 industrial units from different types of production is compiled and then analyzed. Based on the calculations, the approximate amount of CO 2generation in the region was 2105738 kg per day or 768594 tons per year. To absorb and control this amount of CO2 around 35 million trees per year and 23333 hectares of arable land are required. Based on the obtained values, complete management of generated carbon dioxide by green space and tree planting in that area is impossible. It should be noted that these values are calculated for all industrial units of the town in active mode, considering the closure of some of the industrial units, the actual amount will certainly be less than the calculated value.

Roads and transportation infrastructures are national assets that play important role in the development of social welfare. During the construction process, maintenance and the whole life cycle of pavements, huge amounts of natural materials, fossil fuels and electricity are consumed to generate energy, which have deteriorating effects on the environment. Therefore, it is necessary to use management tools and methods to manage the use of natural resources, energy consumption and the effects on the environment in an optimal manner. In this respect, this study uses the life cycle assessment as a tool for quantifying and measuring energy consumptions and global warming potentials at some stages of the life cycle of asphalt pavements. This assessment was applied on four stages of pavement life-cycle, including mining and production of raw materials, hot mix asphalt production, transportation of materials and pavement execution, considering separately the electricity and fuel consumption, and Iran’s electricity situation. Energy consumption and production of greenhouse gases at each stage were calculated based on the collected data and previous studies. Results of this study showed that the hot mix asphalt production stage in the asphalt factory has major effect on the environment with a share of 48% in global warming potential. Also, results of the sensitivity analysis on transport distances showed that variations of materials-transport distance can have an important role in the life cycle assessment results.