Pakistan Research Repository

Investigation Of Impact Of Global Warming On Water Resources Of Pakistan

Ishtiaq, Hassan (2011) Investigation Of Impact Of Global Warming On Water Resources Of Pakistan. PhD thesis, University of Engineering & Technology, Taxila.

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Abstract

The present thesis work has been carried out to forecast the impact of global warming on temperature and precipitation with review of river flows, Simulations for temperature and precipitation have been made using mainly the Educational Global Climate Model (EdGCM). Precipitation and temperature maps on global scale have been produced by this model. Although, the main study was focused on precipitation and temperature of Pakistan, yet for in-depth explorations, the data of another country (Saudi Arabia) was also investigated.EdGCM grid values surrounding the country have been used as input to novel software Eagle Point (EP) and AutoCAD2000i Quick Surf applied for downscaling.Double_CO2 (2CO2) experiment (experiment-1) based on Special Report on Emission Scenarios (SRES) A2 and Modern Predicted Sea Surface Temperature (MPSST) experiment (experiement- 2, baseline for 2CO2 experiment in EdGCM) have been applied to study the impacts of climate changes on precipitation and temperature. Simulations have been carried up to the end of 21st century. Comparative study of Eagle Point and AutoCAD2000i Quick Surf with k-NN (k-nearest neighbor, a statistical method) to study impact of global warming only due to double CO2 experiment on precipitation of Pakistan has been executed. Detailed comparative study for k-NN and Eagle Point Surface Modeling is based on the results of five models (CGCM3, NPCM, CM2.0, ECHAM5-OM and EdGCM) for A2 scenario.It revealed that both Eagle Point Surface Modeling (EP SM) and AutoCAD2000i Quick Surf produced results very close to k-NN approach.Ease in application and visual output of both Eagle Point Surface Modeling and AutoCAD2000i Quick Surf, as compared to k-NN or any other statistical method, would let the future environmental and civil engineers work more comfortably and without doubts. For investigation of changes in temperature, the data of 25 stations for Pakistan and data of 13 stations for Saudi Arabia have been used. For Pakistan, it has been found that there will be a rise in temperature.Temperatures are expected to increase throughout across Pakistan.In case of Saudi Arabia, it has been estimated that severity of stations might remain the same as being experienced at present but all stations of Saudi Arabia are also expected to experience increases in temperatures. Overall change in temperature (by applying results of EdGCM) is 4.79°C for Pakistan and 3.98°C for Saudi Arabia. The above mentioned stations of both the countries (Pakistan and Saudi Arabia) have also been evaluated for investigation of changes in precipitation.For Pakistan, the results of five models (CGCM3, NPCM, CM2.0, ECHAM5-OM and EdGCM) for A2 scenario have been studied and the concluding results, based on these models, have been applied to investigate changes. For both Pakistan and Saudi Arabia, it is observed that precipitation pattern is going to change significantly i.e.occurrence of precipitation in all seasons for Pakistan is expected to increase and occurrence of precipitation in winter for Saudi Arabia might reduce as compared to the present situation.In this way, the precipitation is expected to become almost uniformly distributed across all seasons for both the countries.Average annual precipitation (by applying results of EdGCM) for Pakistan will undergo an increase of 45.12% change compared with base period averages whereas average annual precipitation for Saudi Arabia will undergo an increase of 21.20% change compared with base period averages.The above findings especially for precipitation and temperature changes due to global warming for Pakistan and Saudi Arabia are very much in line with the IPCC (Intergovernmental panel on Climate Change) report. The easier application of Eagle Point Surface Modeling and AutoCAD2000i Quicksurf methods makes the downscaling procedure faster and reduces the errors which are otherwise expected in statistical calculations because in statistical calculations one has to define four nearest grid points’ data (longitude, latitude, P or T value) out of a list of many grid points (e.g. 72 points required to cover Pakistan in ECHAM5-OM output) and a wrong entry may lead to error in station values. On the other hand, in Eagle Point Surface Modeling and AutoCAD QuickSurf applications, the data list is imported directly from ASCII format into an .xls and a .csv format from which the isohyets/isotherms are generated. Graphical super-imposition of study area map with stations can be used to read the station values.This type of methods would be very much helpful for the researchers all over the world.It is, therefore, recommended that future research must also apply these two methods and compare the results with conventional approaches – they will find themselves very comfortable both in terms of efforts and results. Time series analysis of the base period inflows in two rivers i.e. River Indus at Terbela and River Jhelum at Mangla has been carried out to see the evidence of impact of climate change on runoff of these rivers during the base period.This analysis indicated increases in decadal monthly river run-off.Simulations for 21st century, by applying IHACRES stream flow modeling software, have shown increases of approximately 21.07% in inflows at Terbela and 22.50% in inflows at Mangla.These increases are indicative of improvements in water sources of Pakistan in terms of surface waters. Key Words: CGCM3, NPCM, CM2.0, ECHAM5-OM, EdGCM, k-NN Downscaling, Eagle- Point, AutoCAD, Isohyets, Isotherms, GHG (green house gases).

Item Type:Thesis (PhD)
Uncontrolled Keywords:Precipitation, Forecast, Temperature, Investigation, Resources, Stations, Seasons, Warming, Global, Impact, Water, Climate
Subjects:Engineering & Technology (e) > Engineering(e1) > Civil engineering(e1.8)
ID Code:7541
Deposited By:Mr. Javed Memon
Deposited On:29 Nov 2012 15:00
Last Modified:29 Nov 2012 15:00

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