Document Type: Original Article


1 Water Engineering Department, Faculty of Agriculture, Urmia University, Urmia- IRAN

2 Msc Student of Water Engineering Department, Faculty of Agriculture, Tabriz University, Tabriz- IRAN

3 Associate Professorof Water Engineering Department, Faculty of Agriculture, Tabriz University, Tabriz- IRAN

4 Professorof Water Engineering Department, Faculty of Agriculture, Tabriz University, Tabriz- IRAN


One of the most important hydrological time series task is to determine if there is any trend in the data and how to achieve stationarity when there is nonstationarity behavior in data. Detecting trend and stationarity in hydrological time series may help us to understand the possible links between hydrological processes and global climate changes. In this study yearly, monthly and daily streamflow data records of Baranduz Chai, Shahar Chai and Nazlu Chai rivers and Urmia synoptic stattion in the west of Lake Urmia, located in the West Azarbaijan of Iran, used to trend and stationarity analysis. Trend analysis with Mann-Kendall and seasonal Kendall tests showed that most annual and monthly flow series had significant negative trend at 1% and 10% . Five common methods named ADF, DFGLS, ERS, KPSS and PP have been used to examine nonstationarity of river flows. Results demonstrated that most annual, monthly and daily series appear to be stationary after removing trend component from series. Also results illustrated, that mean air temperature of this region increased significantly at 1% level. Increasing air temperature causes changing most of precipitations to rain in the replace of snow that maybe the main reason of river flow decreasing and Lake Urmia depletion in recent years. Furthermore, studied rivers have high dependence on snow melt water, therefore are affected by temperature changes. This showed obviously effect of global warming on the decreasing river flow discharges in the west of Lake Urmia


Main Subjects

Abghari, H., Tabari, H., Talaee, P.H., 2013. River flow trends in the west of Iran during the past 40 years: Impact of precipitation variability. J of Hydrology, 101:52-60.
Balling, R.C.J.r., 1992. The Heated Debate: Greenhouse Predictions versus Climate Reality. Pacific Research Institute for Public Policy, San Francisco, 195 pp,.
Bartlett, M.S., 1950. Periodogram Analysis and Continuous Spectra. Biometrika, 37:1-16.
Birsan, M., Zaharia, L., Branescu, E., and Chendes, V., 2008. Trends in Romanian Stream Flow over the Second Half of the 20th Century. Geophysical Research Abstracts, 10: EGU 2008 – A – 10880, 1607 – 7962.
Burn, D.H., and Hag Elnur, M.A., 2002. Detection of Hydrologic Trends and Variability. Journal of Hydrology, 255: 107-122.
De Wit, M.J.M., 2001. Effect of Climate Change on the Hydrology of the River Meuse. Report 104, Wageningen University, Environmental Sciences, Netherlands.
Dibike, Y., Prowes, T., Shrestha, R., Ahmed, R., 2012. Observed trends and future projections of precipitation and air temperature in the Lake Winnipeg watershed. Journal of Great Lakes Research, 38(3):72-82.
Dickey, D.A., and Fuller, W.A., 1979. Distribution of the Estimators for Autoregressive Time Series with a Unit Root. Journal of American Statistical Association.
Dinpashoh, Y., Jhajharia, D., Fakheri-Fard, A., Singh, V.P., and Kahya, E., 2011. Trends in reference crop evapotranspiration over Iran. Journal of Hydrology, 399: 422–433. DOI:10.1016/j.jhydrol.2011.01.021.
Elliott, G., Thomas, J., Rothenberg, J., and Stock, H., 1996. Efficient Tests for an Autoregressive Unit Root. Econometrica, 64:813-836.
Ghahraman, B., and Taghvaeian, S., 2008. Investigation of annual rainfall trends in Iran. Journal of Agricultural Science and Technology, 10:93–97.
Gimeno, R., Manchado, B., and Mingues, R., 1999. Stationarity Tests for Financial Time Series. Physica. A, 269(1): 72-78.
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.
Hirsch, R.M., and Slack, J.R., 1984. A Nonparametric Trend Test for Seasonal Ddata with Serial Dependence. Water Resources Research, 20(6):727-732.
Jhajharia, D., Dinpashoh, Y., Kahya, E., Singh, V.P., and Fakheri-Fard, A., 2012. Trends in reference evapotranspiration in the humid region of northeast India. Journal of Hydrological Processes, 26:421- 435. DOI: 10.1002/hyp.8140.
Kahya, E., and Kalayci, S., 2004. Trend Analysis of Streamflow in Turkey. Journal of Hydrology, 289:128-144.
Karaburun, A., Demirci, A., and Kara, F., 2011. Analysis of Spatially Distributed Annual, Seasonal and Monthly Temperatures in Istanbul from 1975 to 2006. World Applied Sciences Journal, 12 (10): 1662- 1675.
Karla, A., Piechota, T.C., Davies, R., and Tootle, G.A., 2008. Changes in U.S. Streamflow and Western U.S, Snowpack. Journal of Hydrologic Engineering ASCE, 1084-069.
Kendall, M.G., 1938. A New Measure of Rank Correlation. Biometrika, 36: 81-93.
Kwiatkowski, D., Phillips, P.C.B., Schmidt, P., and Shin, Y., 1992. Testing the Null of Stationarity Against the Alternative of a Unit Root: How Sure are We the Economic Time Series Have a Unit Root? J. Economics, 54: 159-178.
Lettenmaier, D.P., Wood, A.W., Palmer, R.N., Wood, E.F., and Stakhiv, E.Z., 1999. Water Resources Implications of Global Warming, A U.S. Regional Prespective. Clim. Change, 43: 537-579.
Lins, H.F., and Slack, J.R., 1999. Streamflow trends in United States. Geophysical Research Letters, 26(2): 227-230.
MacKinnon, J.G., 1991. Critical values for cointegration tests. Chapter 13 in R.F. Engle and C.W.J. Granger (eds), Long-run Economic Relationships: Readings in Cointegration, Oxford University Press.
Martinez, C.J., Maleski, J.J., Miller, M.F., 2012. Trends in precipitation and temperature in Florida, USA. J of Hydrology, 453:259-281.
Mann, H.B., 1945. Nonparametric test against trend. Econometrica, 13: 245-259.
MCCabe, G.J., and Wolock, D.M., 2002. A step Increase in Streamflow in the Conterminous United States. Geophysical Reasearch Letters, 29 (24): 2185.
Newey, W.K., and West, K.D., 1987. A simple, positive semi-definite, heteroskedasticity and autocorrelation consistent covariance matrix. Econometrica 55: 703-708.
Pfister, L., Humbert, J., and Hoffmann, L., 2000. Recent trends in rainfall-runoff characteristics in the Alzette River Basin, Luxembourg. Climatic Change, 45(2):323 – 337.
Phillips, P.C.B., and Perron, P., 1988. Testing for a unit root in time series regression. Biometrika, 75: 335-346.
Said, S.E., and Dicky, D., 1984. Testing for Unit Roots in Autoregressive Moving Average Models with Unknown Order. Biometrika, 71: 599-607.
Salas, J.D., Delleur, J.W., Yevjevich, V., and Lane, W.L., 1980. Applied Modeling of Hydrologic Time Series. Water Resources Publications, Littleton, Colorado.
Shin, Y., and Schmidt, P., 1992. The KPSS Stationarity Test as a Unit Root Test. Economic Letters, 38: 387-392.
Schwert, G.W., 1989. Test for Unit Roots: A Monte Carlo Investigation. Journal of Business and Economics Statistics, 7: 147-159.
Tabari, A., and Hosseinzadeh-Talaee, P., 2011. Recent trends of mean maximum and minimum air temperatures in the western half of Iran. Journal of Meteorological Atmosphere Physics, 111:121–131.
Van Gelder, P., Kuzmin, V., and Visser, P., 2000. Analysis and Statistical Forecasting of Trends of Hydrological Processes in Climate Changes. In: Proceedings of the International Symposium on Flood Defence, Vol. 1 (Toensmann F. and Koch M., Eds.), Kassel, Germany, pp D13-D22.
Von Storch. H., 1995. Misuses of Statictical Analysis in Climate Research. In: Analysis of Climate Variability: Applications of Statistical Techniques, (Storch HV and Navarra a Eds), Springer Verlag, New York, pp. 11-26.
Wang, Q., Fan, X., Qin, Z., Wang, M., 2012. Change trends of temperature and precipitation in the Loess Plateau Region of China, 1961–2010. Global and Planetary Change, 93: 138-147.
Wang, W., Van Gelder, P.H.A.J.M., and Vrijling, J.K., 2005. Trend and Stationary Analysis for Streamflow Processes of Rivers in Western Europe in 20th Century. IWA International Conference on Water Economics, Statistics and Finance, Rethymno, Greece.
Westmacott, J.R., and Burn, D.H., 1997. Climate Change Effects on the Hydrologic Regime within the Churchill-Nelson River Basin. Journal of Hydrology, 202: 263-279.
Zhang, X., Harvey, K.D., Hogg, W.D., and Yuzyk, R., 2001. Trends in Canadian Streamflow. Water Resources Research, 37 (4): 987-998.