In collaboration with Iranian Watershed Management Association

Document Type : Research Paper

Authors

1 Professor, Faculty of Geography and Planning, University of Tabriz, Tabriz, Iran

2 Assistant Professor, Soil Conservation and Watershed Management Research Center (SCWMRI), Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran

3 PhD Student, Faculty of Geography and Planning, University of Tabriz, Tabriz, Iran

Abstract

In order to monitor spatiotemporal variability of snow in mountainous areas such as Zagros in Iran, long-term records of snow observations with high spatial resolution are required. However, no such data are either observed or available for the stations of the Zagros region. Therefore, in this study, the Era-Interim/Land snow depth data for the period 1979-2010 were used in order to investigate the spatiotemporal variability of snow season length and the associated starting and ending dates in the Zagros region. To do so, for each hydrological year starting from October and ending in September, the first and last snow dates with snow depth equal to or greater than one centimeter were defined as the first and last day of observed snow on the ground and the time period between these two dates was considered as the snow season length. For each grid points over the study area, the time series of snow start and end dates, as well as the length of the snow season, were extracted and the rate of their temporal changes was estimated using the Sen Slope estimator and were examined using the Mann-Kendal trend test to test if they are statistically significant. Moreover, the considered time period was divided into three different sub-periods and the mean values of these parameters (i.e., first and last snow dates and snow season length) in the three sub-periods were also compared. The links between these parameters and the latitude, longitude, and altitude of the grid points were also examined. Results indicated that the spatial pattern of the first and last snow dates and snow season length fairly follow the geographical features of the study area and thus have a statistically significant relationship with the latitude, longitude, and altitude. Time variability of the considered parameters over all the studied grid points revealed that the date of the first snow in the most proportion of the study area retreated towards the late autumn and January and the date of the last snow also retreated towards March and February, thus, resulting in the shorter winter season in recent years. The observed statistically significant decreasing trend in the time series of the last snow dates towards March and February has the most contribution in shortening the length of the snow season.

Keywords

  1. Bagla, P. 2007. Big melt threatens India’s water. Available online at: http://news.sciencemag.org/sciencenow/2007/01/.
  2. Balsamo, G., C. Albergel, A. Beljaars, S. Boussetta, E. Brun, H. Cloke, D. Dee, E. Dutra, J. Muñoz-Sabater, F. Pappenberger, P. de Rosnay, T. Stockdale and F. Vitart. ERA-Interim/Land: a global land surface reanalysis data set. Journal of Hydrology and Earth System Sciences, 19: 389-407.
  3. Bamzai, A.S. 2003. Relationship between snow cover variability and Arctic Oscillation index on a hierarchy of time scales. International Journal of Climatology, 23: 131–142.
  4. Brown, R.D. and P.W. Mote. 2009. The response of Northern Hemisphere snow cover to a changing climate. Journal of Climate, 22: 2124-2145.
  5. Bulygina, O.N., V.N. Razuvaev and N.N. Korshunova. 2009. Changes in snow cover over Northern Eurasia in the last few decades. Journal of Environmental Research Letters, 4: 26-39.
  6. Callaghan, T.V. 2011. The changing face of Arctic snow cover: a synthesis of observed and projected changes. AMBIO, 40: 17–31.
  7. Cayan, D.R., S.A. Kammerdiener, M.D. Dettinger, J.M. Caprio and D.H. Peterson. 2001. Changes in the onset of spring in the western United States. Bulletin of the American Meteorological Society, 82: 399–415.
  8. Choi, G., D.A. Robinson and S. Kang. 2010. Changing Northern Hemisphere snow seasons. Journal of Climate, 23: 5305-5310.
  9. Dewey, K.F. 1977. Daily maximum and minimum temperature forecasts and the influence of snow cover. Monthly Weather Review, 105: 1594–1597.
  10. Dye, D.G. 2002. Variability and trends in the annual snow-cover cycles in Northern Hemisphere land areas, 1972–2000. Hydrological Processes, 16: 3065–3077.
  11. Ghasemi, A. and I. Fatahi. 2012. Evaluation of the effects of climate change on snowmelt runoff: a case study on Bakhtiari Basin. 1st National Conference on Desert, Tehran, Iran (in Persian).
  12. Ghorbanizadeh Kharrazi, H., H. Sedghi, B. Saghafian and J. Porhemmat. 2007. The effects of climate change on the time of maximum snowmelt runoff, a case study on Karun and Dez rivers as the main sources of agricultural water in north of Khuzestan. Journal Scientific and Research of Plant and Ecosystem, 11: 38-50 (in Persian).
  13. Ghorbanizadeh Kharazi, and M. Chelemal Dezfulnejad. 2010. A study on the effect of climate change on snowmelt runoff timingin in Dez Basin. Journal of Science and Professional Talab Islamic Azad University of Ahvaz, 3: 56-66 (in Persian).
  14. Groisman, P.Y., R.W. Knight, V.N. Razuvaev, O.N. Bulygina and T.R. Karl. 2006. State of the ground: climatology and changes during the past 69 years over Northern Eurasia for a rarely used measure of snow cover and frozen land. Journal of Climate, 19: 4933–55.
  15. Hodgkins, G.A., R.W. Dudley and T.G. Huntington. 2003. Changes in the timing of high river flows in New England over the 20th Century. Journal of Hydrology, 278: 244–252.
  16. Irannezhad, M., A.K. Ronkanen and B. Klove. 2016. Wintertime climate factors controlling snow resource decline in Finland. International Journal of Climatology, 36:110-131.
  17. Kitaev, L.M., V.M. Radionov, E. Forland, V.N. Razuvaev and R.A. Martuganov. 2004. Duration of Northern Eurasia snow cover under present climate change conditions. Russian Meteorology and Hydrology, 11: 46–51.
  18. Kitaev, L.M., V.N. Razuvaev, R. Heino and E. Forland. 2006. Snow cover period in Northern Europe. Russian Meteorology and Hydrology, 3: 72–77.
  19. Leathers, D.J. and D.A. Robinson. 1993. The association between extremes in North American snow cover extent and United States temperatures. Journal of Climate, 6: 1345–1355.
  20. Radionov, V.F., E.I. Aleksandrov, V.R. Bayborodova, N.N. Bryazgin and A.A. Dementev. 2004. Long-term changes of snow cover period in the Arctic Data. Glacial Studies, 97: 136–42.
  21. Rahimi, D. and M. Danapour. 2011. Analysis of climate fluctuations affecting snowfall in Kuhrang region. Journal of Scientific-Research Geographic Space of Islamic Azad University Ahar, 38: 75-61 (in Persian).
  22. Rikiishi, K., E. Hashiya and M. Imai. 2004. Linear trends of the length of snow cover season in the Northern Hemisphere as observed by the satellites in the period 1972–2000. Annals of Glaciology, 38: 229–237.
  23. Rikiishi, K. and H. Nakasuto. 2006. Height dependence of the tendency for reduction in seasonal snow cover in the Himalaya and the Tibetan Plateau region, 1966–2001. Annals of Glaciology, 43: 369–377.
  24. Robinson, D.A. and A. Frei. 2000. Seasonal variability of Northern Hemisphere snow extent using visible satellite data. The Professional Geographer, 52: 307–315.
  25. Westerling, A.L., H.G. Hidalgo, D.R. Cayan and T.W. Swetnam. 2006. Warming and earlier spring increase western U.S. forest wildfire activity. Science, 313: 940–943.
  26. Ye, H., H.M. Cho and P.E. Gustafson. 1998. The changes in Russian winter snow accumulation during 1936–1983 and its spatial Journal of Climate, 11: 856–863.
  27. Ye, H. 2000. Decadal variability of Russian winter snow accumulation and its associations with Atlantic Sea surface temperature anomalies. International Journal of Climatology, 20: 1709–1728.
  28. Ye, H. 2001. Quasi-biennial and quasi-decadal variations in snow accumulation over Northern Eurasia and their connections to the Atlantic and Pacific Oceans. Journal of Climate, 14: 4573–4584.
  29. Ye, H. and J. Cho. 2013. Higher air temperatures over Northern Eurasia. Journal of Environmental Research Letters, 8: 1405-1422.

Zhang, X., K.D. Harvey, W.D. Hogg and T.R. Yuzyk. 2001. Trends in Canadian streamflow. Water Resources Research, 37: 987–999.