Quality Control of Precipitation Measurement for Selected Stations in Iraq
Keywords:Quality Control (QC), Homogeneity tests, SNH test, Pettitt test, BR test, VNR test
In this research, quality control and homogeneity tests were performed for 20 surface meteorological stations records in Iraq. For this purpose, the annual precipitation data series at the stations of Iraqi meteorological organizations and seismology for the period (1981-2010) were considered. Quality control procedure involving outlier detection using Mandel’s k method. Homogenization were analyzed by using four absolute methods tests namely SNH test, Pettitt test, BR test and VNR test, these tests were chosen to detect the inhomogeneity in data, the results of each test were evaluated at significance level 0.05. Results of Mandel’s K methodwere classified into four categories (Normal, Abnormal 1, Abnormal 2 and Extreme) and represented in GIS software.The results showed that 5% of station classified as Normal, 20% of stations classified as Abnormal 1, 25% of stations classified as Extreme and 50% of stations were classified as Abnormal 2. The homogeneity tests results displayed that 5% of station assigned as “doubtful” class with break years found in (1998) for (Pettitt and BR) tests, 50% of stations assigned as “useful” class , and the other stations which represent 45% assigned as “suspect” class with break years detected for (Pettitt, SNH and BR) tests most found in (1998 ad 1999) were represents 28% of break years, 21% of break years found in (1997) and other break years found between (1991-2004).
Ouma, J., N.J. Muthama, and A. Opere, Investigating the Homogeneity of Monthly Rainfall Records in Kenya. J. Meteorol, 2016.
Wang, Y., Statistical homogenization of undocumented monthly temperature data in British Columbia for trend analysis. 2018.
Štěpánek, P., P. Zahradníček, and P. Skalák, Data quality control and homogenization of air temperature and precipitation series in the area of the Czech Republic in the period 1961-2007. Advances in Science and Research, 2009. 3(1): p. 23-26. [CrossRef]
González-Rouco, J.F., et al., Quality control and homogeneity of precipitation data in the southwest of Europe. Journal of climate, 2001. 14(5): p. 964-978. [CrossRef]
Wijngaard, J.B., A.M.G. Klein Tank, and G.P. Können, Homogeneity of 20th century European daily temperature and precipitation series. International Journal of Climatology, 2003. 23(6): p. 679-692. [CrossRef]
Mahmood, R. and S. Jia, Quality control and homogenization of daily meteorological data in the trans-boundary region of the Jhelum River basin. Journal of Geographical Sciences, 2016. 26(12): p. 1661-1674. [CrossRef]
Agha, O.M.A.M., S.Ç. Bağçacı, and N. Şarlak, Homogeneity Analysis of Precipitation Series in North Iraq. IOSR Journal of Applied Geology and Geophysics, 2017. 05(03): p. 57-63. [CrossRef]
Shen, L., et al., Homogeneity Test and Correction of Daily Temperature and Precipitation Data (1978-2015) in North China. Advances in Meteorology, 2018. 2018: p. 1-17. [CrossRef]
Malinowski, J.C., W.C. King, and E.J. Palka, Iraq: A Geography. 2002: Department of Geography & Environmental Engineeering, United States Military Academy.
Wilrich, P.-T., Critical values of Mandel's h and k, the Grubbs and the Cochran test statistic. AStA Advances in Statistical Analysis, 2013. 97(1): p. 1-10. [CrossRef]
Alexandersson, H., A homogeneity test applied to precipitation data. Journal of climatology, 1986. 6(6): p. 661-675. [CrossRef]
Jarušková, D., Change-point detection in meteorological measurement. Monthly Weather Review, 1996. 124(7): p. 1535-1543. [CrossRef]
Buishand, T.A., Some methods for testing the homogeneity of rainfall records. Journal of hydrology, 1982. 58(1-2): p. 11-27. [CrossRef]
Pettit, A., Anon-parametric approach to the change-point detection. Appl. Stat, 1979. 28: p. 126-135. [CrossRef]
Von Neumann, J., Distribution of the ratio of the mean square successive difference to the variance. The Annals of Mathematical Statistics, 1941. 12(4): p. 367-395. [CrossRef]
Buishand, T.A., The Analysis of Homogeneity of Long-term Rainfall Records in the Netherlands. 1981: KNMI.
Bingham, C. and L.S. Nelson, An approximation for the distribution of the von Neumann ratio. Technometrics, 1981. 23(3): p. 285-288. [CrossRef]
Schönwiese, C.-D. and J. Rapp, Climate trend atlas of Europe based on observations 1891-1990. 2013: Springer Science & Business Media.
Zakaria, S., N. Al-Ansari, and S. Knutsson, Historical and future climatic change scenarios for temperature and rainfall for Iraq. Journal of Civil Engineering and Architecture, 2013. 7(12): p. 1574-1594. [CrossRef]
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