Volume 2, Issue 6 (1-2012)                   2012, 2(6): 87-107 | Back to browse issues page

XML Persian Abstract Print

Abstract:   (20953 Views)
A Study of the Potential Impact of Climate Change on the Future Droughts in Iran by Using the Global Circulation Models as Outputs Gholamreza Roshan Assistant Professor in climatology, Department of Geography, Golestan University, Gorgan, Iran Mohammad Saeed Najafi  MSc Student in Climatology, Faculty of Geography, Tehran University, Tehran, Iran. Extended Abstract 1- Introduction The development of urbanism and the expansion of cities, coupled with the rapid increase in population and intensification of industrial activities, have led to irregular patterns of consumption of fossil fuels (Roshan et al., 2010), which has caused disarrangement of climate system balance and heightened the climate anomalies. Climate change is often measured by changes in primary climate variables such as global surface air temperature and precipitation (Blenkinsop & Fowler, 2007). Recent and potential future increases in global temperatures are likely to be associated with impacts on the hydrologic cycle, including changes to precipitation and increases in extreme events such as droughts. By developing Atmosphere–Ocean General Circulation Models (GCMs), a modeling of the possibility of future precipitation changes have been provided. In this study the first aim is to assess the emissions scenarios for choosing the best scenario for Iran and the second goal is to analyze the potential changes of drought in the future global warming in Iran. 2- Data & Methods In this study, in order to assess Iran's droughts, two datasets have been used. The first one is Climate data for 70 synoptic and climatologically stations as experimental dataset and the second one is GCM data. To estimate potential future climate changes in droughts in Iran, we used data from the IPCC AR4 General Circulation Model (GCM) simulations. Any one model simulation of future climate may represent only one of many possible future climate states, so for simulating the precipitation climate parameter as results of two Global Circulation Models (GCM), CNRM-CM3 and GISS-EH outputs have been used. In order to introduce proper scenarios, 18 scenarios have been chosen and among this, P50 scenarios have been offered that agree with the condition of greenhouse gas emission in Iran. To analyze the changes in precipitation in the future, mean precipitation amounts were calculated for the years 1961–1990 and compared with each of the GCM control integrations. In addition to, for assessing Iran's droughts, Standard Precipitation Index (SPI) has been used. In current study, we used two time scales, past to now (1976-2005) and future (2025, 2050, 2075, and 2100). The correlation and regression methods for determining the trend of drought in context of time have been used. For the purpose of forecasting and simulating precipitation parameter changes as a result of greenhouse gases dispersion increase, the MAGICC SCENGEN compound model has been used. For developing the drought maps and analyzing them, GIS software and IDW method were used. 3- Results & Discussion Results of the study in 1976-2005 show the most quantity of drought occurrence in 43 studied regions in Iran, was first in winter and then in spring and autumn, which are nearly contrariwise for simulation data. Because of the effect of the global warming occurrence, the most drought risk potential respectively will be in spring, autumn, and winter. But precipitation simulated issues and concerning yearly and long-time mean (1961-1990) beside this mean, show that there will be an increase of rains in all simulated periods. The average change in annual precipitation in the entire country starts with 30.09 mm in 2025, precipitation in 2050 increased about 52.83, in continuation of these changes, 43.73mm is amount of precipitation changes during the 2075, and in finally increase of precipitation ends in 88mm in 2100. The calculation of droughts for simulated data in the future for autumn, the mean of SPI was calculated 0.61 for 2050, 2075 (SPI=0.58), 2025 (SPI=0.53) and in 2100 SPI calculated 0.47 respectively. The results of SPI simulated output in autumn show that the most studied areas are near normal. In winter, the most SPI value was calculated for the year 2100 (SPI=1.16). In this season, 2050 (SPI=1.08), 2025 (SPI=1.01), 2075(SPI=0.99) were calculated. In winter, as in autumn, the most studied areas are near normal. In winter, the minimum of SPI was calculated for northern Khorasan and north of Khorasan Razavi and the Maximum of SPI was calculated for the west of Caspian area and Guilan, west of Kermanshah and Ilam. In the spring, the mean of SPI in 2100 was -0.4, 2050 (SPI=0.11), 2075 (SPI=0.19) and in 2025 (SPI=0.22). So, the risk of drought in spring in comparison with other seasons has increased. 4- Conclusion The general conclusions from the observed data for drought and wet periods that can reach to this result, that’s the ratio of occurrence in significant increasing trend in droughts for a variety of seasons, are greater than wet periods. The results show that in all years and seasons that have been simulated, most wet years will be in the west of Caspian area and Guilan, west of Kermanshah and Ilam furthermore, most risks of drought occurrence for years and seasons have been simulated in northern Khorasan and north of Khorasan Razavi. Key Words: General Circulation Models, Emission Scenarios, Greenhouse, Anomalies, Drought. 5- References - Roshan Gh. R., F. Khoshakh lagh, Gh. Azizi, H. Mohammadi, SIMULATION OF TEMPERATURE CHANGES IN IRAN UNDER THE ATMOSPHERE CARBON DIOXIDE DUPLICATION CONDITION, Iran. J. Environ. Health. Sci. Eng., 2011, Vol. 8, No. 2, pp. 139-15 - Blenkinsop S., H.J. Fowler, (2007), Changes in drought frequency, severity and duration for the British Isles projected by the PRUDENCE regional climate models, Journal of Hydrology. 342, 50– 71. - Andersson, L., Wilk, J., Martin C., Todd, Denis A., Hughes, Earle, A., Kniveton, D., Layberry, R., Hubert, Savenije, H.G.,( 2006). Impact of climate change and development scenarios on flow patterns in the Okavango River, Journal of Hydrology. 331, 43– 57. - Ashok, K. Mishra, Vijay, P. Singh, (2010). A review of drought concepts, Journal of Hydrology 391, 202–216 - Bhalme, H.N., Mooley, D.A., (1980). Large scale drought/floods and monsoon circulation. Monthly Weather Review 108, 1197. - Blenkinsop S., H.J. Fowler, (2007), Changes in drought frequency, severity and duration for the British Isles projected by the PRUDENCE regional climate models, Journal of Hydrology. 342, 50– 71 - Bonaccorso, B., Bordi, I., Cancelliere, A., Rossi, G., Sutera, A., (2003). Spatial variability of drought: an analysis of the SPI in Sicily. Water Resources Management 17, 273–296. - Edmond Pasho, J. Julio Camareroc, Martin de Luisd, Sergio M. Vicente-Serrano, (2011). Impacts of drought at different time scales on forest growth across a wide climatic gradient in north-eastern Spain, Agricultural and Forest Meteorology, 151,1800– 1811 - Elsa E. Moreira, Ana A. Paulo, Luı´s S. Pereira, Joa˜o T. Mexia, (2006), Analysis of SPI drought class transitions using loglinear model, Journal of Hydrology, 331, 349– 359. - H.R. Moradi, M. Rajabi, M. Faragzadeh, (2010), Investigation of meteorological drought characteristics in Fars province, Iran, Catena 84, 35–46. - Hoogwijk M., Faaij A., Vries B., Turkenburg W., (2009). Exploration of regional and global cost–supply curves of biomass energy from short-rotation crop sat abandoned cropland Andres land under four IPCC SRES land-use scenarios, Biomass and Bioenergy. 33, 26–43. - Justin Sheffield Eric F. Wood, (2008), projected changes in drought occurrence under future global warming from multi-model, multi-scenario, IPCC AR4 simulations. Clim Dyn J. 31,79–105 - McKee, T.B., Doesken, N.J., Kleist, J., (1993). The relationship of drought frequency and duration to time scales. In: Preprints, Eighth Conference on Applied Climatology, January 17e22, Anaheim, California, pp. 179e184 - Nigel W. Arnell, (2004). Climate change and global water resources: SRES emissions and socio-economic scenarios, Global Environmental Change 14, 31–52 - Palmer, W.C., (1965). Meteorological drought. Research Paper No. 45, US Weather Bureau, Washington, DC. - Parry, M., (2004). Global impacts of climate change under the SRES scenarios, Global Environmental Change. 14:1. - Paulo, A.A., Pereira, L.S., (2006a). Drought concepts and characterization. Comparing drought indices applied at local and regional scales. Water International 31, 37–49. - Paulo, A.A., Pereira, L.S., Matias, P.G., (2003). Analysis of local and regional droughts in southern Portugal using the theory of runs and the Standardized Precipitation Index. Kluwer, Dordrecht, pp. 55–78. - Roshan, Gh. R., Ranjbar, F., Orosa, J. A., (2010). Simulation of global warming effect on outdoor thermal comfort conditions. Int. J. Environ. Sci. Tech., 7, 571-580. - Rounsevell, M.D.A., Ewert, F., Reginster, I., Leemans, R., Carter, T.R., (2005). Future scenarios of European agricultural land use II. Projecting changes in cropland and grassland, Agriculture, Ecosystems and Environment. 10. 117–135. - Roshan Gh. R., F. Khoshakh lagh, Gh. Azizi, H. Mohammadi, SIMULATION OF TEMPERATURE CHANGES IN IRAN UNDER THE ATMOSPHERE CARBON DIOXIDE DUPLICATION CONDITION, Iran. J. Environ. Health. Sci. Eng., 2011, Vol. 8, No. 2, pp. 139-15 - Sastri, A.S.R.A.S., (1993). Agricultural drought management strategies to alleviate impacts: examples from the arid and sub humid regions of the Indian Subcontinent. In: Wilhite, D.A. (Ed.), Drought Assessment, Management, and Planning: Theory and Case Studies. Kluwer Academic Publishers, Dordrecht, pp. 65e86. - Wigley, T.M.L., (1993), Balancing the Carbon Budget, Implications for projections of future carbon dioxide concentration changes. Tellus 45B, 409-425. - Wigley, T.M.L., (1994a). The Contribution from Emissions of Different Gases to the Enhanced Greenhouse Effect, (In) Climate Change and the Agenda for Research (ed.T. Hanisch), Westview Press, Boulder, CO, 193-222. - Wigley, T.M.L., Jain, A., Joos, F., Shukla, P.R. and Nyenzi, B.S., (1997a). Implications of Proposed CO2 Emissions limitations, IPCC Technical Paper 4 (eds. J.T. Houghton, L.G. Meira Filho, D.J. Griggs and M. Noguer), Intergovernmental Panel on Climate Change, Geneva, Switzerland, pp. 41. - Wigley, T.M.L., Raper, S.C.B., Hulme,M. and Smith,S., (2000). The MAGICC/SCENGEN Climate Scenario Generator: Version 2.4, Technical Manual, Climatic Research Unit,UEA,Norwich, UK, pp. 2-48.
Full-Text [PDF 822 kb]   (3080 Downloads)    
Type of Study: Research |
Received: 05/Nov/12 | Published: 15/Jan/12

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.