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Distributed Modeling of Extraterrestrial Solar Radiation Over the Rugged Terrains of Pakistan

Journal of Mountain Science 2011年第3期8卷 427-436页

作者： romana ambreen QIU Xinfa Iftikhar AHMAD Key laboratory of Meteorological Disaster of Ministry of Education Nanjing University of Information Science & Technology Nanjing 210044 China Department of Geography University of Balochistan Quetta Pakistan

In Pakistan,the solar analogue has been addressed but its surface geographical parameterization has given least *** density of stations and their spatial coverage particularly in difficult peripheral national territories,little or no solar radiation data,non-satisfactory sunshine hours data,and low quality of ground observed cloud cover data create a situation in which the spatial modeling of Extraterrestrial Solar Radiation(ESR) and its ground parameterization got sufficient *** Digital Elevation Model (DEM) input into Geographic Information System (GIS) is a compatible tool to demonstrate the spatial distribution of ESR over the rugged terrains of the study *** the first time,distributed modeling of ESR is done over the rugged terrains of Pakistan,based on DEM and ArcGIS..Results clearly depict that the complex landforms profoundly disrupt the zonal distribution of ESR in *** screening impact of topography is higher on spatial distribution of ESR in winter and considerably low in *** combined effect of topography and latitude is ***,the model was further testified by plotting Rb (ratio of ESR quantity over rugged terrain against plane surface) against azimuth at different latitudes with different angled *** results clearly support the strong screening effect of rugged terrain through out the country especially in Himalayas,Karakoram and Hindukush (HKH),western border mountains and Balochistan *** model can be instrumental as baseline geospatial information for scientific investigations in Pakistan,where substantial fraction of national population is living in mountainous regions.

关键词： Pakistan distributed modeling ESR DEM GIS rugged terrain

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Winter-Spring Precipitation Variability in Pakistan

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American Journal of Climate Change 2015年第1期4卷 115-139页

作者： Iftikhar Ahmad romana ambreen Zhaobo Sun Weitao Deng Department of Geography University of Balochistan Quetta Pakistan Key Laboratory of Meteorological Disaster Ministry of Education Nanjing University of Information Science & Technology Nanjing China

This study investigates the spatial-temporal variability of winter-spring (February-March-April) precipitation (WSP) in Pakistan over the period of 1961-2006 by making use of Empirical Orthogonal Function (EOF). The EOF analysis is based on ground observed data, reanalysis NCEP/NCAR of various geopotential heights and NOAA extended reconstructed sea surface temperatures (ERSST.v3). The significant modes are obviously variable at interannual time scale. The leading mode shows the node of maximum spatial variability anchored over the Peshawar Valley and Azad Kashmir (PVAK) axis. The pattern is associated with strong (weak) westerly jet over the Middle East. The pattern is also found closely associated with post monsoon and early winter El Nino. The Nino4 index can be an appropriate predictor for the first consistent single node pattern. The second significant mode represents a tripole pattern with areas of prominent variability over northwestern Pakistan, Quetta-Kalat region and northeastern Punjab. The pattern is found to be pro-NAO and in relation to this pattern, warm and stable SST anomalies appearing in the southern mid-latitudes of Indian and Atlantic basins.

关键词： Pakistan Winter-Spring Precipitation EOF Spatial Variability Interannual Variability

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Regional and Monthly Assessment of Extraterrestrial Solar Radiations in Pakistan

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Journal of Geographic Information System 2015年第1期7卷 58-64页

作者： romana ambreen Iftikhar Ahmad Xinfa Qiu Menjei Li Department of Geography University of Balochistan Quetta Pakistan Nanjing University of Information Science and Technology Nanjing China

The monthly extraterrestrial solar radiations (ESR) have been simulated separately for all the months of the year. The subtropical location and distribution of mountains and their height determine the spatial distribution and amount of ESR in Pakistan. The mountains, piedmonts, enclosed valleys and plains show distinct diversity of ESR values. The assessment acknowledged that countries like Pakistan with ever increasing demand of energy receive sufficient amount of ESR that could be linked with solar irradiance where development of solar energy has great potential. The simulation was done with the help of ArcGIS based on distributed modeling.

关键词： Pakistan Extraterrestrial Solar Radiation Monthly Spatial Distribution GIS

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Regional and Monthly Assessment of Possible Sunshine Duration in Pakistan: A Geographical Approach

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Journal of Geographic Information System 2015年第1期7卷 65-70页

作者： romana ambreen Iftikhar Ahmad Xinfa Qiu Menjei Li Department of Geography University of Balochistan Quetta Pakistan Nanjing University of Information Science and Technology Nanjing China

The monthly possible sunshine hours have been simulated separately for all the months of the year with the help of ArcGIS. The results are evident that the geography of the area plays a pivotal role in giving shape to spatial distribution of monthly possible sunshine duration (PSD). The landforms distributions and latitudinal extent are the major geographical factors behind the spatial-temporal distribution of monthly PSD. Maps of all the months depict different sunshine hours that vary from region to region in Pakistan. The maximum difference in PSD was noticed between lofty mountains in the north and Indus Plains. In addition, the variation is phenomenal from January to August and vice versa. This sort of study based on spatial modeling is significant in Pakistan where we lack appropriate ground observed data of PSD.

关键词： Pakistan Possible Sunshine Duration Monthly GIS Landforms Impact

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Spatio-Temporal Analysis of Landuse/Landcover Change of District Pishin Using Satellite Imagery and GIS

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Journal of Geographic Information System 2016年第3期8卷 361-368页

作者： Sanaullah Khan Said Qasim romana ambreen Zia-Ul-Haq Syed Department of Geography University of Balochistan Quetta Pakistan

Detecting change on the face of the globe using GIS (Geographic Information System) aided by remotely sensed imagery is now becoming an indispensable tool in managing the resources of our planet. The present study with the help of GIS and remote sensing (RS) is also a similar attempt in recording and quantifying change in land use and land cover in district Pishin both in spatial and temporal extents. Satellite imagery was acquired from the USGS official website from three LANDSAT satellites. Theses satellites are LANDSAT 5, LANDSAT7 and LANDSAT 8. The data were acquired for the years 1992, 2003 and 2013. Satellite imagery was processed in ArcMap 10.1 and maximum likelihood supervised image classification was applied in reaching the goal of detecting change. The result of the analysis revealed that built-up area was increased by 5.84%;vegetation was increased by 3.89%;water bodies were increased by 0.05% and bare surfaces were decreased by 9.78%. The decrease in the barren surfaces was attributed to the increase in vegetation and built-up area which replaced the barren land in the study area. This paper also shows the significance and potential of digital change detection methods in managing the resources of our environment and keeping an eye on the land use and land cover of our Earth.

关键词： Spatial-Temporal Land-Cover Change District Pishin GIS Satellite Imagery

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Spatial-Temporal Variations in January Precipitation over the Period of 1950-2000 in Pakistan and Possible Links with Global Teleconnections: Geographical Perspective

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American Journal of Climate Change 2014年第4期3卷 378-387页

作者： Iftikhar Ahmad romana ambreen Shahzad Sultan Zhaobo Sun Weitao Deng Department of Geography University of Balochistan Quetta Pakistan Pakistan Meteorological Department Islamabad & Institute of Space and Earth Information Science Chinese University of Hong Kong Hong Kong China Key Laboratory of Meteorological Disaster Ministry of Education Nanjing University of Information Science & Technology Nanjing China

Empirical Orthogonal Function (EOF) was performed to investigate spatial variation in January precipitation over Pakistan using ground observed mean monthly precipitation data from 1950-2000 with a combination of gridded reanalysis data of sea level pressure (SLP) and 500 hPa geopotential height. The leading EOF mode captures 37.51% of the total variance and the spatial-temporal variability of January precipitation was consistent in the study area. The temporal changes explicate non-periodic interannual variability and some tacit interdecadal variation. The anomalous condition is more prominent along the western bordering mountains and northern high mountainous region than any other region of Pakistan. Based on results the study reveals spatial-temporal variation in January precipitation and possible links with global teleconnections located both in the proximity as well as in the remote areas from the study locus.

关键词： Pakistan January Precipitation EOF Analysis Spatial-Temporal Variability

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A Study of Decadal December Temperature Variability in Pakistan

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American Journal of Climate Change 2014年第5期3卷 429-437页

作者： romana ambreen Iftikhar Ahmad Shahzad Sultan Zhaobo Sun Muhammad Nawaz Department of Geography University of Balochistan Quetta Pakistan Pakistan Meteorological Department Islamabad Pakistan Institute of Space and Earth Information Science Chinese University of Hong Kong Hong Kong China Nanjing University of Information Science and Technology Nanjing China

The spatial distribution of December temperature in Pakistan has been assessed by statistical method based on mean monthly data from 51 ground stations. The analysis is performed at decadal scale over the period of 1950-2000. December is one of the representative months of winter season in Pakistan, the country with subtropical location and complex rugged terrains, plateaus and plains. The results support a slight rising temperature trend in December. However, this change in temperature varies from region to region as well as from decade to decade and reflects a complicated spatial-temporal structure of temperature anomalies. The assessment shows that the temperature anomalies in different national territories at local scale do not follow the assumption that winter months are warming in northern hemisphere. Both the isothermal shift and temperature anomalies confirm that the mountainous areas of Pakistan face more temperature variability than plains.

关键词： Temperature Anomaly December Pakistan Decadal Scale Spatial Distribution

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Spatial-Temporal Variations in January Temperature in Pakistan and Their Possible Links with SLP and 500-hPa Levels over the Period of 1950-2000: A Geographical Approach

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Atmospheric and Climate Sciences 2014年第4期4卷 524-533页

作者： Iftikhar Ahmad romana ambreen Shahzad Sultan Zhaobo Sun Weitao Deng Department of Geography University of Balochistan Quetta Pakistan Key laboratory of Meteorological Disaster Ministry of Education Nanjing University of Information Science & Technology Nanjing China Pakistan Meteorological Department Islamabad Pakistan

By making use of Empirical Orthogonal Function (EOF) analysis the spatial and temporal variability was investigated in January over the period of 1950 to 2000 in Pakistan. The analysis is based on the combination of ground observed mean monthly temperature data and National Centre for Environmental Prediction (NCEP) reanalysis data of sea level pressure (SLP) and 500-hPa fields. The results reasonably reveal that the variation in January temperature have links with global teleconnections at SLP and 500-hPa pressure heights. The analysis shows variability at interannual to interdecadal time scale. The interannual variation is more prominent than the interdecadal signal of temperature anomaly. The simulated coefficient patterns show reasonable variation with regional detail from south (north) to north (south) in the study area. The study could be useful as baseline information for climate change studies in Pakistan.

关键词： Pakistan January Temperature Interannual Variability Spatial Variations Empirical Orthogonal Function

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Regional Characteristics of Temperature Anomalies in Pakistan with Emphasis on Spatial Distribution at Decadal Scale: A Case Study of August (1950s-2000s)

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Atmospheric and Climate Sciences 2014年第4期4卷 721-726页

作者： Iftikhar Ahmad romana ambreen Shahzad Sultan Zhaobo Sun Muhammad Nawaz Department of Geography University of Balochistan Quetta Pakistan Pakistan Meteorological Department Islamabad Pakistan Institute of Space and Earth Information Science Chinese University of Hong Kong Hong Kong China Nanjing University of Information Science and Technology Nanjing China

In this paper the month of August was assessed from 1950s-2000s based on the temperature data from 53 stations that covers almost all Pakistan. The temperature coefficient has been calculated by making use of linear regression. The results have been mapped that show considerable variability of temperature at decadal scale in different areas of Pakistan. The rugged terrains especially and rest of Pakistan generally reflect significant temperature variability in the decades of 1950s, 1960s, 1970s, 1980s, 1990s and 2000s as well. This change in temperature varies from region to region and decade to decade in Pakistan. The temperature anomalies achieved in the country are complicated at local level and did not follow the simple perception that winter months are warming and summer months are cooling. In this study, a geographical approach has been adopted to explain the spatial-temporal dynamics of temperature variation over the study period in Pakistan with emphasis on regional detail.

关键词： Temperature Anomalies August Decadal Scale Spatial Distribution Pakistan

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Three Tier Fog Networks: Enabling IoT/5G for Latency Sensitive Applications

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China Communications 2019年第3期16卷 1-11页

作者： romana Shahzadi ambreen Niaz Mudassar Ali Muhammad Naeem Joel J.P.C.Rodrigues Farhan Qamar Syed Muhammad Anwar University Engineering and Technology COMSATS University Islamabad Wah campus National Institute of Telecommunications (Inatel) Instituto de Telecomunicac??es University ITMO University of Fortaleza (Unifor)

Following the progression in Internet of Things(IoT) and 5G communication networks, the traditional cloud computing model have shifted to fog computing. Fog computing provides mobile computing, network control and storage to the network edges to assist latency critical and computation-intensive applications. Moreover, security features are improved in fog paradigm by processing critical data on edge devices instead of data centres outside the control plane of users. However, fog network deployment imposes many challenges including resource allocation, privacy of users, non-availability of programming model and testing software and support for the heterogenous networks. This article highlights these challenges and their potential solutions in detail. This article also discusses threetier fog network architecture, its standardization and benefits in detail. The proposed resource allocation mechanism for three tier fog networks based on swap matching is described. Results show that by practicing the proposed resource allocation mechanism, maximum throughput with reduced latency is achieved.

关键词： cloud computing fog networks matching games internet of things

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