Journal of Basic and Applied Sciences  -   Volume 8 Number 2


Long Term Wind Trends Analysis of Coastal Belt of Pakistan

Zeeshan Alam Nayyar, Nayyer Alam Zaigham and Abdul Qadeer

http://dx.doi.org/10.6000/1927-5129.2012.08.02.45

Abstract: Pakistan has a long coastal belt, stretched over an area of more than 1000 km from Indian border in east to Iranian border in west, which has varying nature of geomorphic, geologic and climatic setups. In view to understand the characteristic nature of the area in relevance to undertake the wind energy assessment study, it is imperative to carry out the time-series climatic analyses especially for the wind parameters. Pakistan coastal belt has its unique windy nature because of the monsoon period in summer and land-to-sea wind behavior in winter, which further varies respect to coastal geomorphologic features. A research study has been conducted to analyze the long term wind speed trends for the salient cities lying near the coast of Pakistan. The seasonal decomposition technique, i.e. multiplicative model, was applied for the wind trend analyses using the wind data of 60 years for five major cities namely Karachi, Badin & Hyderabad in Sindh province and Lasbella & Ormara in Balochistan province. The present study describes the methodology adopted for the calculation of long term wind speed trends and subsequent the results indicate different wind variables of long term time-series analyses for the selected five cities.

Keywords: Wind speed, time series analyses, seasonal decomposition, Pakistan

 

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The Effect of Grain Size on Radon Exhalation Rate in Soil Samples of Dera Ismail Khan in Pakistan

Tabassum Nasir and Nisar Ahmad

http://dx.doi.org/10.6000/1927-5129.2012.08.02.29

Abstract: Radon concentration and its exhalation rate has been measured from twenty five soil samples collected from seven different locations of Dera Ismail Khan, in the north west of Pakistan. These samples were crushed after drying and passed through sieves with different sizes of pores to get three grain sizes, £0.595 mm, 0.595-2.00 mm and 2.00-4.00 mm of soil. CR-39 based NRPB (National Radiological Protection Board) radon dosimeters have been used to measure the radon concentration and exhalation rates. The maximum average value of radon exhalation rate has found to be: (3.57±0.38) Bq m-2 hr-1 in the samples having grain size 2.00-4.00 mm and the minimum as: (2.21±0.26) Bq m-2 hr-1, in the samples with grain size £ 0.0595 mm. This indicates that the radon exhalation rate increases with the grain size. The maximum average value of radon exhalation rate has been found in samples collected from river side where soil texture is silty clay loam. The obtained values of radon exhalation rate for all the samples are well below the world average value of 57.60 Bq m-2 hr-1.

Keywords: Radon concentration, Radon exhalation rate, grain size, soil texture.

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