HESSD Hydrology and Earth System Sciences Discussions HESSD Hydrol. Earth Syst. Sci. Discuss. 1812-2116 Göttingen, Germany 10.5194/hessd-8-277-2011 Analyses of relationship between Loess Plateau erosion and sunspots based on wavelet transform Gao P. 1 2 Mu X.-M. 1 2 Li R. 1 2 Wang F. 1 2 Institute of Soil and Water Conservation, Northwest A&F University, 26 Xinong Road, Yangling, 712100, Shaanxi Province, China Institute of Soil and Water Conservation, CAS and Ministry of Water Resources, 26 Xinong Road, Yangling, 712100, Shaanxi Province, China 17 01 2011 8 1 277 303 Copyright: © 2011 P. Gao et al. 2011 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://hess.copernicus.org/preprints/8/277/2011/hessd-8-277-2011.html The full text article is available as a PDF file from https://hess.copernicus.org/preprints/8/277/2011/hessd-8-277-2011.pdf

Loess Plateau is one of the worst soil erosion regions in the world, which may resulted from various factors such as precipitation, land cover and land use, soil, vegetation, human intervention, as well as solar activities. The purpose of this study is to find the relationship between soil erosion and sunspot activity on the Loess Plateau, through analyses of the sunspot relative number and the long-term sediment discharge series in Longmen station in the Yellow River based on the Morlet wavelet method. In this paper, annual sediment discharge series from 1919–2008 in Longmen station and the sunspot relative number were decomposed with Complex Morlet wavelet. The results of real part, modulus and the second power of modulus showed an obvious periodic variability in sediment discharge, with 25–40 years, about 10 years, and less than 10 years scales. There are six centers of energy. From the wavelet variance, 6, 12, and 35 years periods were detected within 50-year scale, and the 35-year period is the most significant one. Similar analyses were conducted for the sunspot relative number during the same period of 1919–2008. The sunspot series showed an 11-year periodic variation, and two energy center. Then, the correlation analyses for 11-year scale were computed. From a long-term period (1919–2008) view, there is no significant correlation between the sediment discharge and the sunspot relative number; however, it is evident that the correlations exist in short-term periods. The results also indicate that the relationships between solar activities and the erosion of the Loess Plateau are complicated.

 References Alexander, W. J. R.: Linkages between solar activity and climatic responses, Energy and Environment, 16(2), 239–254, 2005. Balthasar, H.: Rotational periodicities in sunspot relative numbers, Astron. Astrophys., 471(1), 281–287, 2007. Dima M., Lohmann, G., and Dima, I.: Solar-induced and internal climate variability at decadal time scales, Int. J. Climatol., 25(6), 713–733, 2005. Gan, T. Y., Gobena, A., and Wang, Q.: Precipitation of Western Canada: wavelet, scaling, and multifractal analysis and teleconnection to large-scale climate anomalies, J. Geophys. Res., 112, D10110, https://doi.org/10.1029/2006JD007157, 2007. Gao, P., Zhang, X. C., Mu, X. M., Wang, F., Li, R., and Zhang, X. P.: Trend and change-point analyses of streamflow and sediment discharge in Yellow River mainstream during 1950–2005, Hydrolog. Sci. J., 55(2), 275–285, 2010. Gong, S. Y. and Xiong, G. S.: Sources and geographical distribution of the Yellow River sediment, Yellow River, 1(1), 7–17, 1979. Han, Y. B. and Han, Y. G.: Wavelet analysis of sunspot relative numbers, Chinese Science Bulletin, 47(7), 609–612, 2002. Hong, Y. T., Piao, H. C., and Jiang, H. B.: Erosion of the Loess Plateau with special reference to the records of silt discharged by the Huanghe (Yellow River), Quaternary Sciences, 1, 10–20, 1990. Jay, D. A. and Flinchem, E. P.: Interaction of fluctuating river flow with a barotropic tide: A demonstration of wavelet tidal analysis methods, J. Geophys. Res., 102, 5705–5720, 1997. Jay, D. A. and Flinchem, E. P.: A comparison of methods for analysis of tidal records containing multi-scale non-tidal background energy, Cont. Shelf. Res., 19, 1695–1732, 1999. Krivova, N. A. and Solanki, S. K.: The 1.3-year and 156-day periodicities in sunspot data: Wavelet analysis suggests a common origin, Astron. Astrophys., 394(2), 701–706, 2002. Labat, D., Ababou, R., and Mangin, A.: Introduction of wavelet analyses to rainfall-runoff relationship for a Karstic basin: the case of Licq-Atherey Karstic system France, Ground Water, 39(4), 605–615, 2001. Labitzke, K. and van Loon, H.: Some recent studies of probable connections between solar and atmospheric variability, Ann. Geophys., 11, 1084–1094, 1993. Li, C. H., Yang, Z. F., Huang, G. H., and Li, Y. P.: Identification of relationship between sunspots and natural runoff in the Yellow River based on discrete wavelet analysis, Expert Syst. Appl., 36, 3309–3318, 2009. Mu, J. Z. and Meng, Q. M.: Sediment delivery ratio as used in the computation of the watershed sediment yield, Journal of Sediment Research, (2), 60–65, 1982. Nason, G. P. and von Sachs, R.: Wavelets in time series analysis, Philos. Trans. Roy. Soc., London Ser, A, 357, 2511–2526, 1999. Percival, D. B. and Walden, A. T.: Wavelet methods for time series analysis, Cambridge University Press, Cambridge, UK, 620 pp., 2000. Seleshi, Y., Demaree, G. R., and Delleur, J. W.: Sunspot numbers as a possible indicator of annual rainfall at Addis Ababa, Ethiopia, Int. J. Climatol., 14(8), 911–923, 1994. Shi, H. and Shao, M. A.: Soil and water loss from the Loess Plateau in China, J. Arid Environ., 45, 9–20, 2000. Smith, L. C., Turcotte, D. L., and Isacks, B. L.: Streamflow characterization and feature detection using discrete wavelet transform, Hydrol. Process., 12, 233–249, 1998. Thresher, R. E.: Solar correlates of Southern Hemisphere mid-latitude climate variability, Int. J. Climatol., 22(8), 901–915, 2002. Torrence, C. and Compo, G. P.: A practical guide to wavelet analysis, B. Am. Meteorol. Soc., 79, 61–78, 1998. Wang, G. Q. and Li, T. J.: Simulation of Soil Erosion in the Yellow River Basin, in: Proceedings of the 4th international Yellow River forum on ecological civilization and river ethics, Zhengzhou, China, 20–23 October 2009, 1, 62–71, 2010. Wang, Y. Z., Xue, Y. J., and Peng, Z. F.: Primary study on relationship between runoff/flood and sunspots in the Yellow River, Water Resources and Hydraulic Engineering in Northwest, 8(3), 30–38, 1997. Yin, Z. Q., Ma, L. H., Han, Y. B., and Han, Y. G.: Long-term variations of solar activity, Chinese science bulletin, 52(20), 2737–2741, 2007.