Advertisement

Advances in Atmospheric Sciences

, Volume 35, Issue 8, pp 1094–1099 | Cite as

Increasing Flash Floods in a Drying Climate over Southwest China

  • Chan Xiao
  • Peili Wu
  • Lixia Zhang
  • Robin T. Clark
Notes & Letters

Abstract

In a globally warming world, subtropical regions are generally expected to become drier while the tropics and mid–high latitudes become wetter. In line with this, Southwest China, close to 25°N, is expected to become increasingly prone to drought if annual mean precipitation decreases. However, despite this trend, changes in the temporal distribution of moisture supply might actually result in increased extreme rainfall in the region, whose climate is characterized by distinct dry and wet seasons. Using hourly and daily gauge observations, rainfall intensity changes since 1971 are examined for a network of 142 locations in the region. From the analysis, dry season changes are negligible but wet season changes exhibit a significantly strong downward trend [−2.4% (10 yr)−1], particularly during the past 15 years [−17.7% (10 yr)−1]. However, the intensity of events during the wettest of 5% hours appears to steadily increase during the whole period [1.4% (10 yr)−1], tying in with government statistical reports of recent droughts and flooding. If the opposing trends are a consequence of a warming climate, it is reasonable to expect the contradictory trend to continue with an enhanced risk of flash flooding in coming decades in the region concerned.

Key words

regional water cycle flash floods drought Southwest China 

摘要

在全球变暖的背景下, 通常认为副热带地区降水减少, 热带和中高纬度降水增加. 基于此, 对于中国西南地区, 降水减少, 干旱的潜在风险是增加的、洪涝的潜在风险应该是减少的. 本文研究发现一个有意思的现象, 对于西南这样一个干湿季特别分明的地区, 即便降水在减少, 强降水的风险并没有减少. 通过逐小时等高时空分辨率的降水资料分析发现, 近些年西南地区呈现的降水减少趋势, 主要是由于雨季降水的减少造成的, 干季的降水变化不大, 对全年降水的贡献也不大. 而雨季降水虽然明显减少, 但是雨季强降水并没有减少, 无论是强度大于95%分位的降水事件, 还是降水大于20mm每小时的事件, 都呈增加趋势, 这对于地形复杂的西南地区, 无疑增大了洪涝相关的灾害风险. 相关学者关于未来预估都有类似的结论. 因此, 这种相反的变化趋势(总降水减少, 但强降水增加)对于地方政府适应气候变化而言, 洪涝灾害防御工作和干旱同样值得重视.

关键词

区域水循环 短时强降水 干旱 中国西南地区 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Notes

Acknowledgements

This work was jointly supported by the National Key R&D Program of China (Grant Nos. 2016YFE0102400 and 2017YFC1502701) and the UK–China Research & Innovation Partnership Fund through the Met Office Climate Science for Service Partnership (CSSP) China as part of the Newton Fund.

References

  1. Chen, Y., and P. M. Zhai, 2014: Changing structure of wet periods across southwest China during 1961–2012. Climate Research, 61, 123–131, https://doi.org/10.3354/cr01247. CrossRefGoogle Scholar
  2. Cheng, J. G., H. M. Yan, H. S. Yan, and M. E. Xie, 2009: Analysis on Characteristic and Cause of Severe Climate Disaster in Yunnan. China Meteorology Press, 250 pp. (in Chinese)Google Scholar
  3. Chou, C., and J. D. Neelin, 2004: Mechanisms of global warming impacts on regional tropical precipitation. J. Climate, 17, 2688–2701, https://doi.org/10.1175/1520-0442(2004)017<2688:MOGWIO>2.0.CO;2.CrossRefGoogle Scholar
  4. Chou, C., J. D. Neelin, C. A. Chen, and J. Y. Tu, 2009: Evaluating the “rich-get-richer” mechanism in tropical precipitation change under global warming. J Climate, 22, 1982–2005, https://doi.org/10.1175/2008JCLI2471.1. CrossRefGoogle Scholar
  5. Dai, A. G., 2012: Increasing drought under global warming in observations and models. Nature Climate Change, 3, 52–58, https://doi.org/10.1038/nclimate1633. CrossRefGoogle Scholar
  6. Huang, R. H., Y. Liu, L. Wang, and L. Wang, 2012: Analyses of the causes of severe drought occurring in Southwest China from the fall of 2009 to the spring of 2010. Chinese Journal of Atmospheric Sciences, 36(3), 443–457, https://doi.org/10.3878/j.issn.1006-9895.2011.11101. (in Chinese with English abstract)Google Scholar
  7. IPCC, 2013: Summary for policymakers. T. F. Stocker et al., Eds., Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge and New York.Google Scholar
  8. Li, Y. H., H. M. Xu, and D. Liu, 2009: Features of the extremely severe drought in the east of Southwest China and anomalies of atmospheric circulation in summer 2006. Acta Meteorologica Sinica, 67, 122–132, https://doi.org/10.11676/qxxb2009.013. (in Chinese with English abstract)Google Scholar
  9. Li, Z. X., and Coauthors, 2012: Changes of daily climate extremes in southwestern China during 1961–2008. Global and Planetary Change, 80-81, 255–272, https://doi.org/10.1016/j.gloplacha.2011.06.008. CrossRefGoogle Scholar
  10. Ma, S. M., T. J. Zhou, A. G. Dai, and Z. Y. Han, 2015: Observed changes in the distributions of daily precipitation frequency and amount over China from 1960 to 2013. J. Climate, 28, 6960–6978, https://doi.org/10.1175/JCLI-D-15-0011.1. CrossRefGoogle Scholar
  11. NMIC (National Meteorological Information Center), 2012: Assessment Report of Chinese national meteorological stations’ basic meteorological element daily data sets Version3.0. (in Chinese)Google Scholar
  12. NMIC (National Meteorological Information Center), 2013: Quality Assessment Report of Chinese national meteorological stations’ hourly precipitation data sets Version1.0. (in Chinese)Google Scholar
  13. Qin, J., J. H. Ju, and M. E. Xie, 1997: Weather & Climate over Low Latitudes Plateau. China Meteorology Press, 210 pp. (in Chinese)Google Scholar
  14. Qiu, J., 2010: China drought highlights future climate threats. Nature, 465, 142–143, https://doi.org/10.1038/465142a. CrossRefGoogle Scholar
  15. Sun, L., F. M. Ren, Z. Y. Wang, Y. Y. Liu, Y. J. Liu, P. L. Wang, and D. Q. Wang, 2012: Analysis of climate anomaly and causation in August 2011. Meteorological Monthly, 38, 615–622. (in Chinese with English abstract)Google Scholar
  16. Tan, H. J., R. S. Cai, J. L. Chen, and R. H. Huang, 2017: Decadal winter drought in Southwest China since the late 1990s and its atmospheric teleconnection. International Journal of Climatology, 37, 455–467, https://doi.org/10.1002/joc.4718. CrossRefGoogle Scholar
  17. Wang, L., W. Chen, and W. Zhou, 2014: Assessment of future drought in Southwest China based on CMIP5 multimodel projections. Adv. Atmos. Sci., 31(5), 1035–1050, https://doi.org/10.1007/s00376-014-3223-3. CrossRefGoogle Scholar
  18. Wang, L., W. Chen, W. Zhou, and G. Huang, 2015a: Drought in Southwest China: A review. Atmospheric and Oceanic Science Letters, 8, 339–344, https://doi.org/10.3878/AOSL20150043. Google Scholar
  19. Wang, L., W. Chen, W. Zhou, and G. Huang, 2015b: Teleconnected influence of tropical Northwest Pacific sea surface temperature on interannual variability of autumn precipitation in Southwest China. Climate Dyn., 45, 2527–2539, https://doi.org/10.1007/s00382-015-2490-8. CrossRefGoogle Scholar
  20. Wu, J., B. T. Zhou, and Y. Xu, 2015: Response of precipitation and its extremes over China to warming: CMIP5 simulation and projection. Chinese Journal of Geophysics, 58(5), 461–473, https://doi.org/10.1002/cjg2.20187. CrossRefGoogle Scholar
  21. Wu, P. L., R. Wood, J. Ridley, and J. Lowe, 2010: Temporary acceleration of the hydrological cycle in response to a CO2 rampdown. Geophys. Res. Lett., 37, L12705, https://doi.org/10.1029/2010GL043730. Google Scholar
  22. Xu, Z. Q., K. Fan, and H. J. Wang, 2015: Decadal Variation of Summer Precipitation over China and Associated Atmospheric Circulation after the Late 1990s. J. Climate, 28, 4086–4106, https://doi.org/10.1175/JCLI-D-14-00464.1. CrossRefGoogle Scholar
  23. Zhang, M. J., J. Y. He, B. L. Wang, S. J. Wang, S. S. Li, W. L. Liu, and X. N. Ma, 2013: Extreme drought changes in Southwest China from 1960 to 2009. Journal of Geographical Sciences, 23(1), 3–16, https://doi.org/10.1007/s11442-013-0989-7. CrossRefGoogle Scholar
  24. Zhang, Q., Y. F. Zhao, and S. H. Fan, 2016: Development of hourly precipitation datasets for national meteorological stations in China. Torrential Rain and Disasters, 35(2), 182–186, https://doi.org/10.3969/j.issn.1004-9045.2016.02.011. (in Chinese with English abstract)Google Scholar

Copyright information

© British Crown (administered by Met Office); Chan XIAO, and Lixia ZHANG 2018

Authors and Affiliations

  • Chan Xiao
    • 1
  • Peili Wu
    • 2
  • Lixia Zhang
    • 3
  • Robin T. Clark
    • 2
  1. 1.National Climate CentreChina Meteorological AdministrationBeijingChina
  2. 2.Met Office Hadley CentreExeterUK
  3. 3.Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina

Personalised recommendations