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Comparison of aerosol optical depth products from multi-satellites over densely populated cities of Pakistan

100%

Butt F. M. , Shahzad M. I. , Khalid S. , Iqbal N. , Rasheed A. , Raza G.

International Letters of Natural Sciences

2018

tom 69

Air pollution in Pakistan is causing damage to health, environment and quality of life. Air pollution in Pakistan is not effectively monitored due to heavy cost involved in setting up ground stations. However, Satellite remote sensing can effectively monitor the air pollution in terms of Aerosol Optical Depth (AOD) at regional as well as global level. However, algorithms used to derive AOD from different sensors have some inherited differences which can pose challenges in monitoring regional AOD at high temporal resolution using more than one sensor. Therefore, this study focuses on comparison of four major satellite based AOD products namely Moderate Resolution Imaging SpectroRadiometer (MODIS), Multi-angle Imaging SpectroRadiometer (MISR), Ozone Monitoring Instrument multiwavelength (OMI) aerosol product and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) with the ground based AErosol RObotic NETwork (AERONET) AOD which is only available from Lahore and Karachi in Pakistan. The correlation of various AOD products with AERONET AOD is estimated statistically through coefficient of determination (R²), Root Mean Square Error (RMSE), slope and intercept. It is noticed that MODIS is relatively accurate and reliable for monitoring air quality on operational bases over the land cover area of Lahore (R² = 0.78; RMSE = 0.18), whereas MISR over the coastal areas of Karachi (R² = 0.82; RMSE = 0.20). The results of the study will help the stakeholders in planning additional ground stations for operational monitoring of air quality at regional level.

Climate change variability trends and implications for freshwater resources in Pakistan’s eastern Hindu Kush region

84%

Hussain N. , Ali S. , Hussain A. , Ali S. , Khan S. W. , Raza G. , Abbas Q. , Hussain I. , Hussain M.

Polish Journal of Environmental Studies

2018

tom 27

nr 2

Due to climate change, the world average surface temperature has increased 0.3-0.6ºC over the past 100 years. The northern belt of Pakistan holds the largest storage of freshwater (ice and snow) after the polar region, and provides water to the downstream population for agriculture plus domestic and hydropower resources. This study focuses on a possible explanation for the seemingly declining behavior of Darkut Glacier using evidence from ground observation and climate station data in Yasin and Gupis valleys in northern Pakistan. We analyzed data obtained from two stations includes the Water and Power Development Authority of Pakistan (WAPDA, 1995-2010) and the Pakistan Meteorology Department (PMD, 1986-2015). Results of both climate station data depicted an increase in total precipitation and a decrease in winter and spring seasons. The study also highlighted an increase in mean minimum and maximum temperatures, particularly in winter and spring. Similarly, the trend of solar radiation also has decreased. Therefore, enhanced snout fluctuation and the melting rate of Darkut occurred during the study period. All of these changes have had a negative impact on the snout of the glacier, which has retreated 6 m during 2013 and 2016, and a lake has formed behind the terminal moraine.

Assessing natural forest conservation using diameter size class distributions in Pakistan

67%

Hussain J. , Akbar M. , Ali S. , Kui Z. , Raza G. , Khan A. , Zafar M. , Syed N. M. , Hyder S. , Hussain A. , Hussain F.

Polish Journal of Environmental Studies

2020

tom 29

nr 1