Modifying Annual Precipitation Mean Concerning the Effects of Heteroscedasticity in Different Climatic Regions of Iran

Document Type : Original Article

Authors

1 Assistant Professor, Department of Natural Resources Engineering , Faculty of Agriculture and Natural Resources, University of Hormozgan, Bandar Abbas, Iran.

2 Ph.D. Student of Watershed Management Science and Engineering, Faculty of Agriculture and Natural Resources, University of Hormozgan, Bandar Abbas, Iran

Abstract

Heteroscedasticity as determining concept challenges the calculation and efficiency of mean precipitation at the extent of Iran territory. This inefficiency leads to emergence of error during calculation of annual water budget and of problem in water resources of country. Accordingly, in this study, building on the Masoodian climatic classification and investigating the precipitation data from146 synoptic stations at four temporal scales- heavy rain, semi-heavy rain, pre-precipitation, and low rain- the effect of Heteroscedasticity on mean precipitation were investigated by Levene Test. The results showed that besides the precipitation data have a normal distribution across all climatic regions, but the existence of limiting precipitations as outliers data, very high-variances and the variation of precipitation regimes from some station of a climatic region, resulted in rejection of null hypothesis of Levene Test and most of climatic regions are encountered Heteroscedasticity. Consequently, use of mean index could not provide complete recognition of precipitation status and precipitation distribution. Hence, to achieve an efficient mean of annual precipitation in country, it is necessary to do practice to enhance the calculated mean precipitation in climatic extent, with avoiding calculating mean at territory extent, and by accomplishment of improved climatic classification at watershed basin scale, gains better recognition of precipitation behavior at any climatic extent, and at whole territory extent in Iran.

Keywords

References

Alijani B (2013) Climate of Iran (Geography). PNU press (In Persian)
Alijani B (2014) Synoptic Climatology. SAMT Press (In Persian)
Alizadeh A (2013) Principles of applied hydrology. Ferdowsi University Press (In Persian)
Alizadeh A, Kamali GA, Mousavi F, and Mousavi-Bygi M) 2006) Weather and climate. Ferdowsi University Press (In Persian)
Asakereh H (2012) Fundamentals of statistical climatology. University of Zanjan Press (In Persian)
Asakereh H and Dostkamian M (2015) Survey of role of spatial factors on distribution- dispersion of maximums perceptible water in atmosphere of Iran. Researches in Geographical Sciences 15(36):7-24 (In Persian)
Asakereh H, Movahedi S, Sabziparvar A, Masoodiyan SA and Matyanaji Z (2015) Climatology of Iran precipitation by using harmonic analysis method. Geographical Researches Quarterly Journal 29(4):15-26 (In Persian)
Bazargan Lari A (2012) Applied statistics. University of Shiraz Press (In Persian)
Behboodian J (1998) Introductory statistics and probability. Imam Reza Press (In Persian)
Daemi AR (2008) Drought phenomenon from the perspective of water resources. Ministry of Energy, http:www.moe.gov.ir (In Persian)
Dinpajooh Y, Fakheri Fard A, Moghaddam Vahed M, JahanBakhsh S, and Mirnia MK (2003) Selection of variables for the purpose of regionalization of Iran’s precipitation climate using multivariate methods. Iranian Journal Agric Sci 34(4):809-823 (In Persian)
Downs GW and Rocke DM (1979) Interpreting heteroscedasticity. American Journal of Political Science 23(4):816-828
Gelfand SJ (2015) Understanding the impact of heteroscedasticity on the predictive ability of modern regression methods. M.Sc. Thesis, Department of Statistical and Actuarial Science Faculty of Science. Simon Fraser University
Gonzalez-Hidalgo JC, Brunetti M, and de Luis M (2010) Precipitation trends in Spanish hydrological divisions 1946–2005. Climate Research Clim Res 43:215-228
Heydari H and Alijani B (2000) Regionalization of Iran climate using multivariate statistical techniques. Quarterly Geographical Research 37(0):57-74 (In Persian)
Holisaz A, Safikhany S, and MalekHosseini B (2018) Supermodel as a proposed necessity for integrative casual Chain Models in Water Resources. Iran-Water Resources Research Journal 14(1):285-290 (In Persian)
Iran Current Weather (2019) Products and Services. [Online]. Available: http:www.irimo.ir (In Persian)
Kavyani MR and Alijani B (2008) The foundations of climatology. SAMT Press (In Persian)
Mahdavi M (2010) Applied hydrology (vol.1). University of Tehran Press (In Persian)
Masoodian S.A (2003) Climatic regions of Iran. Geography and Development Iranian Journal 1(2):171-184 (In Persian)
Masoodian SA (2003) Investigation of precipitation geographical dispersion in Iran through rotated factor analysis. Geography and Development Iranian Journal 1(1):79-87 (In Persian)
Masoodian SA (2005) Recognition of precipitation regimes of iran using cluster analysis. Geographical Researche Quarterly 37(52):47-59 (In Persian)
Masoodian SA (2009) Precipitation regions of Iran, geography and development Iranian Journal 7(13):79-91 (In Persian)
Masoodian SA (2012) Climate of Iran. Shariee Toos Press (In Persian)
Masoodian SA and Ataei H (2005) A cluster analysis of precipitation seasons of Iran. Research Bulletin of Isfahan University (Humanities) 18(1):1-12 (In Persian)
Masoodian SA and Kavyani MR (2008) Climate of Iran. University of Isfahan Press (In Persian)
Masoodian SA Keykhosravi Kiani MS, and Rayatpishe F (2014) Introduction and a comparison among gridded precipitation database of Asfazari with GPCC, GPCP and CMAP. Geographical Researches Quarterly Journal 29(1):73-88 (In Persian)
Masoodian SA, Rayatpishe F, and Keykhosravi Kiani MS (2015) Introducing the TRMM and Asfezari precipitation database: A comparative study. Iranian Journal of Geophysics (IJG) 8(4):15-31(In Persian)
Mohammadi B and Masoodian SA (2010) Synoptic analysis of heavy precipitation events in Iran. Geography and Development Iranian Journal 8(19):47-70 (In Persian)
Movahedi S, Asakereh H, Sabziparvar A, Masoodian SA, and Maryanaji Z (2012) Assessment of variability of precipitation regime in Iran. Journal of Water and Soil 25(6):1434-1447 (In Persian)
Nadi M and Khalili A (2013) Classification of Iran’s precipitation climate using factor-cluster analysis method. Iranian Journal of Soil and Water Research 44(3):235-242 (In Persian)
Nadi M, Jamei M, Bazrafshan J, and Janatrostami S (2012) Evaluation of different methods for interpolation of mean monthly and annual precipitation data (Case study: Khuzestan Province). Physical Geography Research 44(4):117-130 (In Persian)
Nasrabadi E (2013) Networks of rainfall databases. Journal of Geographical Data (SEPEHR) 22(86):83-88 (In Persian)
Paepe R, Fairbridge RW, Jelgersma S, and Marinus A P (1990) Greenhouse effect, sea level and drought. Kluwer Academic Publishers
Rezai A) 2004) Concepts of probability and statistics. Mashhad Press (In Persian)
Shalabh S.h (2019) Econometric theory. http:home.iitk.ac.in.~shalab.
Shams M and Mahdiyan B (2015) Multicollinearity, heteroscedasticity and consequences its. 2nd National Conference on Applied Research in Mathematics and Physics, University of Applied Science and Technology-Tehran, 22 Jan (In Persian)
Sotoudeh F and Alijani B (2015) The relationship between spatial distribution of heavy precipitation and pressure patterns in Guilan Province. Jsaeh 2(1):63-73 (In Persian)
Teimouri F and Bazrafshan O (2017) Analysis of temporal distribution of rainfall in Iran over the past four decades. Geography and Development Iranian Journal 15(48):171-188 (In Persian)
Williams R (2015) Heteroskedasticity. https://www3.nd.edu/~rwilliam
Yazdi Samadi B, Amiri Oghan A, and Peighambari SA (2007) Applied statistics and probability. University of Tehran Press (In Persian)
Iran-Water Resources Research
Volume 15, Issue 4
December 2019
Pages 171-186

Files

History

  • Receive Date: 26 June 2019
  • Revise Date: 04 October 2019
  • Accept Date: 04 October 2019

Share

How to cite

Statistics