The Heavy Rainfall Event Leading to the Large Debris Flow at Zhouqu

Qian Weimiao; Luo Yali; Zhang Renhe; Gong Yu

Vol.22, NO.4, 2011

Article Contents

Article Navigation > Journal of Applied Meteorological Science > 2011 > 22(4): 385-397

Qian Weimiao, Luo Yali, Zhang Renhe, et al. The heavy rainfall event leading to the large debris flow at Zhouqu. J Appl Meteor Sci, 2011, 22(4): 385-397.

Citation:

Qian Weimiao, Luo Yali, Zhang Renhe, et al. The heavy rainfall event leading to the large debris flow at Zhouqu. J Appl Meteor Sci, 2011, 22(4): 385-397.

Qian Weimiao, Luo Yali, Zhang Renhe, et al. The heavy rainfall event leading to the large debris flow at Zhouqu. J Appl Meteor Sci, 2011, 22(4): 385-397.

Citation:

Qian Weimiao, Luo Yali, Zhang Renhe, et al. The heavy rainfall event leading to the large debris flow at Zhouqu. J Appl Meteor Sci, 2011, 22(4): 385-397.

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The Heavy Rainfall Event Leading to the Large Debris Flow at Zhouqu

State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081

Received Date: 2010-10-14
Rev Recd Date: 2011-04-14
Publish Date: 2011-08-31

Abstract

Abstract

Heavy rainfall occurs abruptly at Zhouqu, Gansu Province at night of 7 August 2010, causing disastrous debris flow and bringing about more than a thousand casualties. To find out the possible triggering mechanism of this rainfall, observations by Automatic Meteorological Stations are used to analyze temporal variation of the surface temperature and spatial distribution of rainfall; brightness temperature data from MTSAT satellite are adopted to reveal evolution of convective clouds; NCEP/NCAR 1°×1° reanalysis data are used to investigate the large-scale atmospheric conditions; AIRS satellite observations are examined to analyze the atmospheric instability; and ECMWF 0.125°×0.125° forecast data are employed to study the convection. First, over Zhuoqu and its upstream (northwest) region, the rapid increase of surface air temperature and the cold air advection in the rear area of the upper-level trough significantly enhanced the conditional instability in the morning of 7 August, favoring formation and development of deep convection. Second, several small-scale convergence centers and lines at the ground surface, generated by interactions among the southerly warm and northerly cold air flow near the ground surface and the complex terrain elevation, triggered the formation of the precipitating convective clouds around 14:00 7 August 2010 (Beijing Time). Third, the southerly air flow between the strong Northwest Pacific Subtropical High and the typhoon "Dianmu" changed to easterly at 23°—30°N, transporting water vapor toward the west until reaching the eastern side of Tibetan Plateau, and then changed to northward, supplying abundant moisture for the raining storm over Zhouqu and its upstream region. At last, the convective clouds moved toward southeast following the upper-level air flow, arrived at Zhouqu and produced heavy rainfall at night of 7 August, leading to the large debris flow at Zhouqu.Satellite remote sensing observations play an important role in the diagnosis of this synoptic process. The infrared brightness temperature (TBB) from the MTSAT satellite reveals the occurrence, development, movement and weakening of the convective clouds which directly produced the heavy rainfall at Zhouqu. The air column temperature and moisture data observed by the AIRS satellite around 14:30 7 August 2010 are used to analyze convective available potential energy (CAPE) and level of neutral buoyancy (LNB) height. The results indicate that atmosphere over Zhouqu—Qinghai Lake region is strongly unstable with the area-averaged CAPE of 4393 J·kg^-1 and LNB height of 16.54 km.
- Tibetan Plateau;
- level of neutral buoyancy;
- moist static energy;
- meso-scale convergence

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References(27)

Figures and Tables

图 1 2010年8月7日08：00—8日08：00自动气象站24 h累积降水量

(灰色阴影：地形高度；白色圆圈：舟曲位置；黑色曲线：青海湖)

Fig. 1 Precipitation accumulated during 08:00 7 August—08:00 8 August in 2010 at individual AMS stations

(gray area: terrain elevation; white circle: Zhouqu; Qinghai Lake is circled by black solid line)

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Fig. 2 Synoptic background at 14:00 7 August 2010 (×: Zhouqu) (a) geopotential height (black line, unit: gpm) and wind (arrow) at 700 hPa (gray shaded represents the area with terrain elevation above 700 hPa), (b) geopotential height (black line, unit: gpm), decrease in temperature from 08:00 to 14:00 (color shaded) and wind (arrow) at 500 hPa, (c) geopotential height (black line, unit: gpm), positive divergence (color shaded) and wind (vector) at 200 hPa

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图 3 MTSAT卫星观测的红外亮温水平分布的时间演变

(彩色阴影：红外亮温；灰色阴影：地形高度；×：舟曲位置)

Fig. 3 Temporal evolution of horizontal distribution of TBB observed by the MTSAT satellite

(color shaded: TBB; gray shaded: terrain elevation; ×: Zhouqu)

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图 4 2010年8月7日12：00与08：00的近地面空气温度差 (单位：℃)

(灰色阴影：地形高度；×：舟曲位置)

Fig. 4 Differences in surface air temperature between 12:00 and 08:00 on 7 August 2010 (unit: ℃)

(gray shaded: terrain elevation; ×: Zhouqu)

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Fig. 5 Time series of surface air temperature at the area of 34°—37.5°N, 100°—104°E from 08:00 7 August to 08:00 8 August in 2010

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图 6 2010年8月7日14：35对流有效位能的水平分布

(灰色阴影：地形高度；白色圆圈：舟曲位置；黑色轮廓：青海湖)

Fig. 6 Horizontal distribution of CAPE at 14:35 7 August 2010

(gray shaded: terrain elevation; white circle: Zhouqu; Qinghai Lake is circled by black solid line)

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图 7 2010年8月7日14：35对流零浮力层高度的水平分布

(灰色阴影：地形高度；白色圆圈：舟曲位置；黑色轮廓：青海湖)

Fig. 7 Horizontal distribution of LNB height at 14:35 7 August 2010

(gray shaded: terrain elevation; white circle: Zhouqu; Qinghai Lake is circled by black solid line)

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图 8 大气湿静力能 (a)、感热 (b)、潜热 (c) 的垂直廓线

(灰线：四川盆地 (28°~32°N, 104°~106°E)；黑线：青海湖—舟曲地区 (32°~37°N, 100°~105°E))

Fig. 8 Vertical distributions of moist static energy (a), sensible heat (b) and latent heat (c)

(gray line: Sichuan Basin (28°—32°N, 104°—106°E); black line: Qinghai Lake—Zhouqu (32°—37°N, 100°—105°E))

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图 9 2010年8月7日地面辐合和红外亮温、700 hPa温度和比湿、地面风、海平面气压、地形高度的水平分布

(图9b，9c中白线：地面风辐合线；图9b，9c中白色方框：地面风辐合区；×：舟曲位置；左上方黑实线：青海湖轮廓) (a)14：30 MTSAT卫星红外亮温水平分布 (彩色阴影)、地形高度 (灰色阴影)，(b)14：00 700 hPa温度场 (灰色阴影)、地面风场 (矢量)、海平面气压场 (彩线)，(c)14：00 700 hPa比湿场 (灰色阴影)、地面风场 (矢量)、海平面气压场 (彩线)，(d)14：00地面风场 (矢量)、地形高度 (彩色阴影)

Fig. 9 Horzontal distribution of surface wind convergence, TBB, temperature and specific humidity at 700 hPa, surface wind, and sea level pressure on 7 August 2010 and terrain elevation

(white lines and white boxes in Fig. 9b, 9c represent surface wind convergence lines and surface wind convergence areas, respectively; ×: Zhouqu; black solid line at the left-upper of each panel: Qinghai Lake) (a) horizontal distribution of TBB (color shaded) observed by MTSAT satellite at 14:30 with terrain elevation (gray shaded), (b) temperature (gray shaded) at 700 hPa, surface wind (arrow), sea level pressure (color line) at 14:00, (c) specific humidity (gray shaded) at 700 hPa, surface wind (arrow), sea level pressure (color line) at 14:00, (d) surface wind (arrow) at 14:00 and terrain elevation (color shaded)

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图 10 2010年8月7日14：00地面至100 hPa积分的水汽通量(矢量)和水汽通量辐合区(虚线,单位：10^-5s^-1·hPa)

(灰色阴影：地形高度在700 hPa以上的区域； ×：舟曲位置；黑粗箭头：水汽输送通道)

Fig. 10 Water vapor flux integrated vertically from ground to 100 hPa (arrow) and convergence of the water vapor flux (dashed line, unit: 10^-5s^-1·hPa) at 14:00 7 August 2010(gray shaded: area with terrain elevation above 700 hPa; ×: Zhouqu; black thick arrow: water vapor channel)

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Table 1 Means and standard deviations of CAPE, LNB height, and MSE, SHE, LHE at the heights of 2.5 to 5.0 km over Qinghai-Zhouqu region and Sichuan Basin at 14:35 7 August 2010

物理量	青海湖—舟曲地区		四川盆地
物理量	平均值	标准偏差	平均值	标准偏差
对流有效位能/(J·kg^-1)	4393	2669	847	616
对流零浮力层高度/km	16.54	1.32	12.89	1.33
大气湿静力能/(J·kg^-1)	352740	10209	339784	4132
感热/(J·kg^-1)	286445	5687	284212	4555
潜热/(J·kg^-1)	25886	10302	18905	6183

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References

[1]	郑永光, 张小玲, 周庆亮, 等.强对流天气短时临近预报业务技术进展与挑战.气象, 2010, 36(7): 33-42. doi: 10.7519/j.issn.1000-0526.2010.07.008
[2]	朱磊磊. 山东两次强对流天气过程机理的分析研究. 山东: 中国海洋大学, 2008.
[3]	张晓美. 华南暖区暴雨中尺度对流系统的观测分析与诊断研究. 北京: 中国气象科学研究院, 2008.
[4]	井喜, 李栋梁, 李明娟, 等.青藏高原东北侧一次突发性大暴雨环境场综合分析.高原气象, 2008, 27(1): 46-57. http://www.cnki.com.cn/Article/CJFDTOTAL-GYQX200801005.htm
[5]	张弘, 孙伟.初夏青藏高原东侧一次特大暴雨的综合分析.高原气象, 2005, 24(2):232-239. http://www.cnki.com.cn/Article/CJFDTOTAL-GYQX20050200E.htm
[6]	费增坪, 王洪庆, 张焱, 等.基于静止卫星红外云图的MCS自动识别与追踪.应用气象学报, 2011, 22(1):115-122. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20110112&flag=1
[7]	刘新伟, 段海霞, 赵青云.甘肃一次区域性大暴雨分析.干旱区研究, 2010, 27(1):128-134. http://www.cnki.com.cn/Article/CJFDTOTAL-GHQJ201001025.htm
[8]	祁秀香, 郑永光. 2007年夏季我国深对流活动时空分布特征.应用气象学报, 2009, 20(3):286-294. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20090304&flag=1
[9]	廖晓农, 愈小鼎, 王迎春.北京地区一次罕见的雷暴大风过程特征分析.高原气象, 2008, 27(6):1350-1362. http://www.cnki.com.cn/Article/CJFDTOTAL-GYQX200806020.htm
[10]	牟容, 于君, 刘德.重庆2008年7月21日强对流天气成因及其特征.气象, 2009, 35(5):49-54. doi: 10.7519/j.issn.1000-0526.2009.05.007
[11]	孙虎林, 罗亚丽, 张人禾. 2009年6月3—4日黄淮地区强飑线天气过程成熟阶段特征分析.大气科学, 2011, 35(1):1-16. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK201101010.htm
[12]	徐祥德, 陈联寿.青藏高原大气科学试验研究进展.应用气象学报, 2006, 17(6): 756-772. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=200606124&flag=1
[13]	江吉喜, 项续康, 范梅珠.青藏高原夏季中尺度强对流系统的时空分布.应用气象学报, 1996, 7(4): 473-478. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=19960472&flag=1
[14]	卓嘎, 徐祥德, 陈联寿.青藏高原对流云团东移发展的不稳定特征.应用气象学报, 2002, 13(4): 448-456. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20020460&flag=1
[15]	江吉喜, 范梅珠.夏季青藏高原上的对流云和中尺度对流系统.大气科学, 2002, 26(3): 263-270. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK200202011.htm
[16]	代刊, 何立富, 金荣花.加密观测资料在北京2008年9月7日雷暴过程分析中的综合应用.气象, 2010, 26(7):160-167. doi: 10.7519/j.issn.1000-0526.2010.07.023
[17]	魏新功, 王振国, 包红霞.降水原因造成的舟曲县地质灾害分析.甘肃科技, 2008, 24(21):84-88. doi: 10.3969/j.issn.1000-0952.2008.21.030
[18]	[2010-10-08]. http://weather.news.sina.com.cn/news/2010/0808/58105.html.
[19]	韩林宏.舟曲县水土保持及生态安全在全县经济社会发展中的战略地位.农业科技与信息, 2006, 8:18-19. doi: 10.3969/j.issn.1003-6997.2006.01.015
[20]	http://www.weather.com.cn/news/910671.shtml.
[21]	丁一汇.高等天气学.北京:气象出版社, 2005:315-336.
[22]	刘新, 吴国雄, 李伟平.夏季青藏高原加热和环流场的日变化.地球科学进展, 2006, 21(12): 1273-1281. doi: 10.3321/j.issn:1001-8166.2006.12.009
[23]	盛裴轩, 毛节泰, 李建国, 等.大气物理学.北京:北京大学出版社, 2003:82-83;155-158.
[24]	Lin Yuh-Lang. Mesoscale Dynamics. Cambridge: Cambridge University Press, 2007: 238-239.
[25]	何金海, 王振会, 银燕, 等译.大气科学.北京:科技出版社, 2008:83-92.
[26]	Richard H J. Surface mesohighs and mesolows. Bull Amer Meteor Soc, 2001, 82(1):13-31. doi: 10.1175/1520-0477(2001)082<0013:SMAM>2.3.CO;2
[27]	朱乾根, 林锦瑞, 寿绍文, 等.天气学原理和方法.北京:气象出版社, 2007: 226-227.