Zohreh Maryanaji; Sayyed Akbar Hosseini; Hamed Abbasi
Abstract
Extended Abstract Introduction Growing demands for energy, increasing living standards and increasing use of electrical energy along with the overheating of planet Earth, as well as environmental problems and threats to human health are among the issues that attract the world’s attention to the ...
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Extended Abstract Introduction Growing demands for energy, increasing living standards and increasing use of electrical energy along with the overheating of planet Earth, as well as environmental problems and threats to human health are among the issues that attract the world’s attention to the use of renewable energies. So, new energy resources, including wind energy, account for one third of the energy needed for countries in the annual planning. Since Hamadan is one of the provinces in Iran with severe winds with relatively good continuity, the use of this energy in wind turbines is indispensable for generating electricity at the provincial level, especially in impassable areas. Today, many dangers, including the threat of climate, change the Earth’s environment. This controls the methods that can reduce the use of renewable energies such as solar, geothermal, wind, etc. Strong and frequent winds are very important energy sources for many parts of the country. In this study, the average and maximum wind speed yearly energy (annually and seasonally) and its energy based on the data from nine synoptic stations in Hamadan province in the climate period of 2000-2014 have been analyzed and spatial velocity of wind speed and its energy in this region were studied. Materials & Methods: The length of the statistical period in the present study was 10 years. After checking the accuracy of the data, the mean and maximum of the seasonal and annual wind speed were calculated and drawn. Then wind energy was calculated using wind power density (watts per square meter), air density (g / cm3), wind speed (m/s). To investigate the spatial distribution of wind energy potential in Hamadan province based on the obtained information, the values were zoned using Kriging method in GIS. Finally, the probability of occurrence and the prediction of the return period of wind were calculated using the Log Pearson type 3 method. Results & Discussion According to the zoning plan, the maximum annual wind speed in the Hamadan is related to the southern parts of the province. Some parts of the province in Kabudrahang are accompanied by intense storms. In winter, maximum wind speed is determined by the instability of air and weather in areas of Hamadan province. The Average annual wind speed zoning pattern indicates that the east parts of Hamadan and some parts of Malayer and Razan have the highest average wind speed (above 3 meters per second), while in other parts of the province it is less than 3 meters per second. The Eastern part of Hamadan province (from the South east to the North east), are the windiest region of the province, and in most of the times of a year these parts have the potential of wind power production. Some regions of the Southwest are also capable of producing wind power during the year. Conclusion The role of topography on wind speed in Hamadan province is noteworthy. The mountainous regions of the province such as Hamadan, Nahavand and Asadabad are more exposed to the winds of the plains - mountains. Hot wind is also one of the meteorological phenomena due to the mountain effects, which is often found in the city of Hamadan. The East and parts of the city of Malayer, and especially in the Northern areas of the province with the highest average wind speed (above three meters per second) and the West and Southwest shown with minimum wind speed during the period specified. Most of the year, the most windy areas, Eastern and Northern regions of the province, have the ability to produce electricity from wind energy. Kabodarahang plain areas of the city of Razan have the highest wind energy potential in watts per square meter and the greatest potential for energy production from wind in Hamadan is in spring and autumn. In the studied area, Nojeh station (North of the province) with more than 18%, and then Malayer station (Southeast of the province) with more than 17%, have the priority for establishing wind turbines due to wind speed persistence. By studying the occurrence of wind speed in the meteorological stations of Hamadan province, some areas of the Razan plain and Kabudrahang are suitable for planning wind power usage.
Hossein Mohammadi; Mohammad Hasan Mahoutchi; Mahdi Khazaei; Esmaeil Abbasi
Abstract
Probability analyses are useful methods for recognizing and predicting phenomena such as precipitation. One of these methods is the Markov chain. The Markov chain model is a special state of the models in which the current state of a system depends on its previous states. With this method, it is possible ...
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Probability analyses are useful methods for recognizing and predicting phenomena such as precipitation. One of these methods is the Markov chain. The Markov chain model is a special state of the models in which the current state of a system depends on its previous states. With this method, it is possible to calculate the probability of the occurrence andthe return period of climatic phenomena such as precipitation.Therefore, in the present research,using the 58 year daily precipitation data (1956 - 2013) ofShiraz synoptic station, the frequency and the continuity of rainy days in this city were studied by the use of the Markov chain model. The above statisticswere arranged based on the matrix of counting the changes of the occurrence states of the dry and wet days (days without precipitation and precipitation days), then, the situation change matrix was calculated based on the maximum likelihood estimation method. The matrix was evaluated and analyzed with repeated, constant power, and daily rainfall return period. Next, the return periods of 2 to 5 day rainfall days and the return period of1 day dry days, were also evaluated. Then,the return period of the continuation of 2 to 5 day precipitation days for twelve months of the year was calculated. The results showed that the probability of precipitation occurrence (wet days) per day was %0.1167 and the probability of no precipitation occurrence (drydays) was %0.8833. It was also determined that the most probable occurrence of rainy days was during the winter, especially in January and February. For example, the return period of 2 consecutive rainy days in January was estimated to be nearly 5 days. Therefore, it was observed that Shiraz precipitation has a heterogeneoustime distribution. In other words, precipitation is not uniform and concentrated in Shiraz.
