Analysis of late spring frost dates over Iran under current climate and future scenarios
Tóm tắt
Frost damage, especially in spring, can have profound effects on agricultural and horticultural crops so that in some years, Iranian insurance companies have to pay millions of dollars of cost to the farmers. It seems that the costs tend to change due to changing in frost features under future climate scenarios. Therefore, the purpose of the study is to investigate these changes and examining the ability of SDSM and Artificial Neural Network (ANN) to downscale AOGCM output data HadCM3 (A2 and B2 scenarios) and CGCM3 (A1B and A2 scenarios). To this end, daily minimum temperature data (Tmini
) of 50 synoptic stations all over Iran for the last 50 years (1961–2010) were collected and quality controlled. The trend analyses of Late Spring Frosts (LSF) dates during historical period showed a significant (at the confidence level of 5%) downward trend of 1.4 days per decade, especially after 1980s. Consequently, statistical tests including Wilcoxon rank-sum method, Levene’s test, and bootstrapping were applied, respectively to compare the mean and variance of LSF dates and to determine the uncertainty of LSF dates at the 95% confidence level. Results revealed that, (a) performance of both downscaling techniques in simulating averages is much better than variance, (b) SDSM simulates warmer summers and colder winters in comparison with ANN; (c) the best and worst accordance between observations (during 2001–2010) and different projections obtained from ANN_CGCM3_A2 and ANN_HadCM3_B2, respectively. Finally, different zones of average dates of LSF occurrence (0 °C or colder) and their areas at current condition and three future scenario period (2011–2040, 2041–2070, 2071–2100) were quantified and compared. According to results, SDSM simulated the probable effects of climate change on LSF more intensively compared to the ANN model.
Tài liệu tham khảo
Anandhi A, Zion MS, Gowda PH, Pierson DC, Lounsbury D, Frei A (2013) Past and future changes in frost day indices in Catskill Mountain region of New York. Hydrol Process 27(21):3094–3104
Brown MB, Forsythe AB (1974) Robust tests for the equality of variances. J Am Stat Assoc 69(346):364–367
Conover WJ (1980) Practical Nonparametric statistics, 2nd edn. Wiley, New York
Cooter EJ, Leduc SK (1995) Recent frost date trends in the north-eastern USA. Int J Climatol 15(1):65–75
Coulibaly P, Dibike YB, Anctil F (2005) Downscaling precipitation and temperature with temporal neural networks. J Hydrometeorol 6(4):483–496
Easterling DR (2002) Recent changes in frost days and the frost-free season in the United States. Bull Am Meteorol Soc 83(9):1327–1332
Efron B (1987) Better bootstrap confidence intervals. J Am Stat Assoc 82(397):171–185
Gagnon S, Singh B, Rousselle J, Roy L (2005) An application of the statistical downscaling model (SDSM) to simulate climatic data for streamflow modelling in Québec. Can Water Resour J 30(4):297–314
Huang J, Zhang J, Zhang Z, Xu C, Wang B, Yao J (2011) Estimation of future precipitation change in the Yangtze River basin by using statistical downscaling method. Stoch Environ Res Risk A 25(6):781–792
Kartschall T, Wodinski M, von Bloh W, Oesterle H, Rachimow C, Hoppmann D (2015) Changes in phenology and frost risks of Vitis vinifera (cv Riesling). Meteorol Z 189–200
Khalili A (2014) Quantitative evaluation of spring frost risk to agricultural and horticultural crops in Iran and modeling. J Agric Meteorol 2(1):17–31
Khalili A, Rahimi J (2014) High-resolution spatiotemporal distribution of precipitation in Iran: a comparative study with three global-precipitation datasets. Theor Appl Climatol 118(1–2):211–221
Lehmann EL (1975) Nonparametrics: statistical methods based on ranks. Holden and Day, San Francisco
Levene H (1960) Robust tests for equality of variances. Contrib Probab Stat 1:278–292
Mahmood R, Babel MS (2013) Evaluation of SDSM developed by annual and monthly sub-models for downscaling temperature and precipitation in the Jhelum basin, Pakistan and India. Theor Appl Climatol 113(1–2):27–44
Menzel A, Jakobi G, Ahas R, Scheifinger H, Estrella N (2003) Variations of the climatological growing season (1951–2000) in Germany compared with other countries. Int J Climatol 23(7):793–812
Qian B, Jong RD, Gameda S, Huffman T, Neilsen D, Desjardins R, Wang H, McConkey B (2013) Impact of climate change scenarios on Canadian agroclimatic indices. Can J Soil Sci 93(2):243–259
Rahimi J, Ebrahimpour M, Khalili A (2013) Spatial changes of extended De Martonne climatic zones affected by climate change in Iran. Theor Appl Climatol 112(3–4):409–418
Rahimi J, Khalili A, Bazrafshan J (2017) Evaluation of different missing data reconstruction methods for daily minimum temperature in elevated stations of Iran: comparison with new proposed approach. Iran J Soil Water Res 48(2):231–238 [In Persian]
Scheifinger H, Menzel A, Koch E, Peter C (2003) Trends of spring time frost events and phenological dates in Central Europe. Theor Appl Climatol 74(1–2):41–51
Wilby RL, Dawson CW, Barrow EM (2002) SDSM—a decision support tool for the assessment of regional climate change impacts. Environ Model Softw 17:147–159