Suchergebnisse

This paper is aimed at studying the spatial changes in agricultural patterns practiced in the suburbs of Karachi, which is the most densely populated city of Pakistan with high food demands of the inhabitants. This study deals mainly with Physical factors primarily climatic indicators to observe and analyze the changes in the pattern of agricultural production and the types of crops in last 20-30 years. Variability of climate when coupled with anthropogenic factors play important role in the acceleration of problems for farmers. Trends of associated agricultural output observed in different years of high and low rainfall. This study has successfully demonstrated inquisitive approach by using published secondary data from governmental sources and ground verification in recent times. Temporal variation in biomass, was found dependent upon pattern of rainfall and temperature etc. Study reveals that there are clear signs of desertification and drought in the study area.

Keti Bunder is a small coastal community situated at about 200 km south east of Karachi. It has four major creeks namely Chann, Hajamro, Kangri (Turchhan) and Khober with an arid subtropical climate and temperature remaining moderate throughout the year. This paper reports the application of an integration of Remote Sensing (RS) and Geographic Information Systems (GIS) for analysis and monitoring of the relationship of land surface temperature (LST) with Normalized Difference Vegetation Index (NDVI) in the area. LST is one of the critical elements in the natural phenomena of surface energy and water balance at local and global extent. [1-5]. Remote sensing in accord with tradition utilizes the NDVI to provide specific information on vegetation abundance to the LST–vegetation relationship. For mapping purposes, satellite images of Landsat-5 ETM+, Landsat-7 TM and Landsat-8 OLI / TIRS images, acquired on March 08, 2000, April 29, 2010 and April 08, 2014 respectively, were used. The results indicate that the maximum land surface temperature increased gradually from 39°C in 2000, to 42°C in 2010 and 45°C in 2014. Due to global warming and climatic changes. Keti Bunder of the Indus delta has experienced a serious condition over the past few years; the local communities have suffered badly from climate change impacts as heavy rainfalls, floods and cyclones have forced people to migrate to other places for their livelihood and shelter. However, mean NDVI value increased to -0.009 in 2014 as compared to 2010 (-0.165), due to several plantations of mangroves being established by the government. In the past, the mangrove forest was degraded due to lack of freshwater and seawater intrusion. The rate of degradation of mangrove forest in the delta was approximately 6 percent per year between 1980 and 1995 and only a small percentage of mangroves are now considered to be healthy [6-7].

The alignment of gas pipelines in a rugged terrain has always been a serious challenge around the globe but they can be perfectly aligned with the help of Geo-Spatial technologies. When South Zarghun gas fields were discovered in Pakistan, gas transmission pipeline laying process between gas fields and Quetta city was as challenging task for the Government of Pakistan. Very rough terrain and extreme weather conditions especially in winter season were the two major constraints for the alignment of pipeline. Geomatics survey was essential before transmission pipeline construction work, done twice by private consultant in Pakistan's local geographic coordinate system. SSGC took decision in 2006 for the construction of pipeline but unfortunately it could not be executed due to law & order situation in Pakistan especially in Balochistan province and later all bench marks of pipeline alignment route were vanished by the locals. In 2012, SSGC again started pipeline construction work on war steps. Previous pipeline alignment survey was converted into existing SSGC's GIS coordinate system i.e. UTM Zone 42 WGS84 using ESRI ArcGIS software. Identification & re-installation of all bench marks and re-routing of pipeline were done by SSGC GIS survey team with the help of global positioning system (GPS) and satellite data. Finally, right of way (ROW) of transmission pipeline from Zarghun gas fields to Quetta city was designed and produced in the form of GIS map for pipeline construction activities.