عنوان مقاله [English]
Evaluation of the rainfall phenomenon is important as the most effective meteorological factors that influence the access to the water resources directly. In this research precipitation concentration index (PCI) calculated using of monthly precipitation time series of 34 synoptic stations in the recent half century (1961-2010) and their trends in two annual and seasonal scales investigated. The results of the zoning the mentioned index in annual scale showed that concentration of the precipitation in two 25 years time reach followed from the same pattern. Also results of PCI index showed that rainfall was scattered irregular in the center and southern regions of Iran in the Kerman, Bandar Abbas, Yazd, Zahedan, Shahrekord, Birjand, Bushehr, Ahwaz and Isfahan also in none of the mentioned stations uniform concentration (PCI <10) were not observed in the annual time scale. Results of winter trend investigation of PCI index in the period of 1961-2010 showed that non-significant upward and downward trend occurred for the number of sixteen and fifteen stations respectively and in the Dezful, Saghez and Hamedan stations significant decreasing trend observed. Also in the spring season, PCI index results showed significant increasing in the PCI trend for two Kerman and Ramsar stations which means that scattering rainfall was irregular significantly in two mentioned stations. In summer, the Gorgan station showed high irregularity as the PCI index and in autumn, the Tabriz and Zahedan stations showed significant increasing trend while decreasing trend detected for Bablosar station. In annual scale about 50 percentages followed increasing of PCI index values.
عساکره،ح.، رزمی،ر. 1391. تحلیل بارش سالانه شمالغرب ایران. مجله جغرافیا و برنامهریزی محیطی.47. 3: 162-147.
میرعباسی،ر.، دینپژوه،ی. 1391. تحلیل بارشهای شمالغرب ایران در نیم قرن گذشته. مجله علوم و مهندسی آبیاری. 35. 4: 73-59.
Adegun,O., Balogun,I and Adeaga,O. 2012. Precipitation Concentration Changes in Owerri and Enugu. Hydrology for Disaster Management, Special Publication of the Nigerian Association of Hydrological Sciences, 391-383.
Alijani,B., O’Brien,J and Yarnal,B. 2008. Spatial analysis of precipitation intensity and concentration in Iran. Theoretical and Applied Climatology. 94: 107-124.
Chen,j., Wub,X., Finlayson,B., Webber,M., Wei,T and Li,M. 2014. Variability and trend in the hydrology of the Yangtze River, China: Annual precipitation and runoff. Journal of Hydrology. 513: 403-412.
Dinpashoh,Y., Mirabbasi,R., Jhajharia,D., ZareAbianeh,H and Mostafaeipour,A. 2014. Effect of short term and long-term persistence on identification of temporal trends. Journal of Hydrologic Engineering 19.3: 617-625.
Duhan,D and Pandy,A. 2013. Statistical analysis of long term spatial and temporal trends of precipitation during 1901–2002 at Madhya Pradesh, India. Atmospheric Research. 122: 136-149.
Gozzini,B., Bartolini,G and Torrigiani,T. 2012. Precipitation concentration patterns in Tuscany (central Italy) 1955-2010. European Annual Meetings. Vol. 9, EMS2012-339, 2012. 12th EMS / 9th ECAC.
Hamed,K.H and Rao,A.R. 1998. A modified Mann–Kendall trend test for autocorrelated data. Journal of Hydrology. 204: 182–196.
Hirsch,R.M., Slack,J.R and Smith,R.A. 1982. Techniques of trend analysis for monthly water quality data, Water Resources Research. 18.1: 107-121.
Jain,SK., Kumar,V and Saharia,M. 2013. Analysis of rainfall and temperature trends in northeast India. International Journal of Climatology. 33: 968-978.
Jiang,T., Su,B and Hartmann,H. 2007. Temporal and spatial trends of precipitation and River flow in the Yangtze River basin, 1961-2000. Geomorphology. 85: 143-154.
Kendall,M.G. 1975. Rank Correlation Measures, Charles Griffin, London.
Khalili,K., Nazeri Tahroudi,M., Mirabbasi,R., Ahmadi,F. 2015. Investigation of spatial and temporal variability of precipitation in Iran over the last half century. Stochastic Environmental Research and Risk Assessment, 1-17.
Khalili,K., Nazeri Tahrudi,M and Khanmohammadi,N. 2014. Trend Analysis of Precipitation in Recent Two Decade over Iran. Journal of Applied Environmental and Biological Science. 4.1:5-10.
Kumar,S., Merwade,V., Kam,J and Thurner,K. 2009. Stream flow trends in Indiana: Effects of long term persistence, precipitation and subsurface drains. Journal of Hydrology. 374: 171-183.
Luis,M.de., Gonz´alez-Hidalgo,J.C., Brunetti,M and Longares,L.A. 2011. Precipitation concentration changes in Spain 1946–2005. Natural Hazards and Earth System Sciences. 11: 1259–1265.
Mann,H.B. 1945. Nonparametric test against trend, Econometrica 13: 245-259.
Oliver,J.E. 1980. Monthly precipitation distribution: a comparative index, Prof. Geogr., 32, 300–309, 1980.
Pal Al-Tabbaa,A. 2009. Trends in seasonal precipitation extremes—an indicator of ‘climate change’ in Kerala, India. Journal of Hydrology. 367: 62–69.
Saboohi,R., Soltani,S and khodagholi,M. 2012. Trend analysis of temperature parameters in Iran. Theoretical and Applied Climatology. 109: 529–547.
Tabari,H., Marofi,S., Aeini,A., Talaee,P.H and Mohammadi,K. 2010. Trend analysis of reference evapotranspiration in the western half of Iran. Agricultural and Forest Meteorology. 151 .2: 9 pages.
Vali,M., Shanti Sree,K and Iyyanki,V.M.K. 2013. Analysis of Precipitation Concentration Index and Rainfall Prediction in various Agro-Climatic Zones of Andhra Pradesh, India. International research journal of environment research. 2.5: 53-61.
Yang,X.L., Xu,L.R., Li,C.h., Hu,J and Xia,X.H. 2012. Trends in temperature and precipitation in the Zhangweinan River basin during last 53 years. Procedia Environmental Sciences. 13: 1966-1774.