岷江上游潜在性泥石流堰塞湖危害及判识
作者简介:柳金峰(1979-),男,安徽泾县人,助理研究员,主要从事山地灾害实验与防治工程研究。E-mail:liujf@imde.ac.cn
收稿日期: 2011-05-03
要求修回日期: 2011-09-12
网络出版日期: 2012-07-20
基金资助
国家科技支撑计划课题(2009BAK56B05)、国家自然科学基金项目(40971014)资助
Potential Damages and Identification of Debris Flow Barrier Lakes in theUpper Min River Drainage
Received date: 2011-05-03
Request revised date: 2011-09-12
Online published: 2012-07-20
Copyright
柳金峰 , 游勇 , 陈兴长 . 岷江上游潜在性泥石流堰塞湖危害及判识[J]. 地理科学, 2012 , 32(7) : 885 -891 . DOI: 10.13249/j.cnki.sgs.2012.07.885
The Wenchuan earthquake caused numerous landslides and collapses that provided abundant loose solid materials for future mobilization as debris flows. The formation conditions for debris flows were changed consequently. Debris flows will be very active for a long time in the affected area. Their secondary disaster, barrier lake, is beginning to appear. Therefore, it is urgent to identify those debris flow gullies which are potential to form barrier lakes following the environmental changes caused by the earthquake. This paper selected the upper Min River from Yinxiu to Wenchuan as study area, analyzed the changed formation conditions of debris flows and the damages of a typical debris flow barrier lake, and interpreted the loose solid materials from TM satellite images and aerial photographs. Then, the identification factors were selected and classified based on the factor independence analysis. At last, the fuzzy matter-element extension theory was used to construct a model to identify potential barrier lakes. The potential future increase in debris flow activity relates directly to the great increase in loose materials. The interpretation results indicated that the area of the landslides and collapses caused by the earthquake is 39.40 km2, accounting for 6.97% of the total study area. Assuming 55% of the landslide and collapse area were their deposition area and the average deposition depth was 10 m, the volume of the loose solid materials can be estimated as 2.13×108m3 which was sufficient for debris flow formation. Based on the factor independence analysis, the volume of the loose solid materials per unit area, the discharge ratio between the debris flow gully and the main river, the slope gradient of debris flow channel, the main river width, and the included angle between the debris flow gully and the main river were determined as identification factors. According to the multi-factor comprehensive identification, among the 55 first-grade gullies, 17 gullies have high probabilities for potential debris flow barrier lakes, 15 have moderate probabilities, and 23 gullies have low probabilities. The most likely debris flow gullies for forming barrier lakes mainly distribute in the middle-to-lower reaches of the study area (Yingxiu Town to Caopo Town), and those with moderate and low probabilities are mainly distributed in the upper reaches of the study area (Caopo Town to Wenchuan County). In addition, among the 17 potential debris flow gullies with high probabilities, 4 gullies already yielded barrier lakes during the 2008-2010 rainy seasons. The remaining debris flow gullies will produce barrier lakes in the future with high probability.
Key words: Upper Min River; debris flow; barrier lakes; potential damages; identification
Fig.1 The geology, rainfall of the study area and debris flow distribution before and after earthquake图1 研究区地质、降水及地震前后泥石流沟分布 |
Fig.2 The debris flow barrier lake of Guanshan gully and its damages图2 关山沟泥石流堰塞湖及其危害 |
Fig.3 The distribution of landslides induced by earthquake图3 研究区崩塌和滑坡分布 |
Table 1 The classification of the indices for potential debris flow barrier lakes identification表1 潜在性泥石流堰塞湖判识指标分级 |
泥石流堰塞湖发生可能性 | 低 | 中 | 高 |
---|---|---|---|
单位面积松散物源 方量c1(×104m3/km2) | <10 | 10~50 | >50 |
支主流量比c2 | <0.5 | 0.5~1 | >1 |
泥石流沟床比降c3(‰) | <100 | 100~300 | >300 |
主河宽度c4(m) | >100 | 50~100 | <50 |
主支夹角c5(°) | <30 | 30~90 | >90 |
Fig.4 The identification results of the potential debris flow barrier lakes图4 潜在泥石流堰塞湖判识结果 |
Table 2 The characteristic value of first-grade gullies and identification results of the potential debris flow barrier lakes表2 研究区典型一级支沟特征值及潜在泥石流堰塞湖判识结果 |
编号 | 沟名 | 流域面积 | 主沟长度 | 相对高差 | 主沟比降 | 松散物方量 | 支主流量比 | 主河宽度 | 主支夹角 | 判识 结果 |
---|---|---|---|---|---|---|---|---|---|---|
(km2) | (km) | (m) | (‰) | (×104 m3) | (m) | (°) | ||||
M1 | 郭主铺沟 | 5.70 | 5.27 | 2093 | 345 | 98 | 0.43 | 60 | 97 | 低 |
M2 | 万村沟 | 2.85 | 3.49 | 1645 | 425 | 0 | 0.23 | 66 | 83 | 低 |
M3 | 新桥沟 | 15.33 | 6.20 | 2292 | 272 | 245 | 1.35 | 67 | 76 | 中 |
M4 | 七盘沟 | 52.65 | 15.51 | 3070 | 153 | 938 | 4.38 | 74 | 101 | 中 |
M5 | 磨刀溪沟 | 1.75 | 2.69 | 1741 | 582 | 34 | 0.25 | 100 | 88 | 低 |
M6 | 板桥沟 | 27.18 | 11.19 | 3008 | 210 | 363 | 2.38 | 79 | 92 | 中 |
M7 | 板子沟 | 54.73 | 17.15 | 4035 | 176 | 581 | 1.75 | 52 | 96 | 中 |
M8 | 小茅坪沟 | 3.57 | 3.29 | 1768 | 483 | 16 | 0.32 | 56 | 77 | 低 |
M9 | 木瓜圆沟 | 3.74 | 3.17 | 2032 | 509 | 16 | 0.43 | 82 | 101 | 低 |
M10 | 大溪沟 | 15.76 | 7.63 | 2863 | 273 | 779 | 1.66 | 82 | 107 | 高 |
M11 | 马埝坪沟 | 43.38 | 15.22 | 3762 | 185 | 1421 | 2.18 | 82 | 87 | 高 |
M12 | 苏村沟 | 6.03 | 5.00 | 2333 | 373 | 163 | 0.58 | 121 | 43 | 中 |
M13 | 簇头沟 | 21.89 | 8.94 | 2933 | 262 | 1108 | 1.62 | 89 | 126 | 高 |
M14 | 高店子沟 | 7.35 | 5.01 | 2434 | 389 | 86 | 0.72 | 108 | 101 | 低 |
M15 | 瓦窑坪沟 | 1.20 | 3.09 | 1825 | 532 | 13 | 0.11 | 88 | 100 | 低 |
M16 | 新店沟 | 2.77 | 4.00 | 2069 | 439 | 50 | 0.26 | 60 | 86 | 低 |
M17 | 小坪下沟 | 2.04 | 2.80 | 1615 | 502 | 75 | 0.22 | 127 | 102 | 中 |
M18 | 窰子沟 | 7.14 | 4.67 | 2060 | 362 | 104 | 0.81 | 80 | 101 | 低 |
M19 | 华溪沟 | 10.41 | 6.46 | 1968 | 239 | 55 | 0.84 | 113 | 52 | 低 |
M20 | 大水沟 | 2.14 | 2.96 | 1664 | 478 | 80 | 0.15 | 89 | 58 | 中 |
M21 | 石马山7#沟 | 0.67 | 1.88 | 1339 | 606 | 8 | 0.05 | 80 | 56 | 低 |
M22 | 石马山6#沟 | 0.49 | 1.36 | 1170 | 747 | 13 | 0.04 | 75 | 97 | 低 |
M23 | 石马山5#沟 | 0.36 | 1.26 | 1144 | 791 | 11 | 0.03 | 69 | 112 | 低 |
M24 | 桃关沟 | 50.69 | 14.28 | 3000 | 161 | 1644 | 2.91 | 75 | 73 | 高 |
M25 | 石马山4#沟 | 1.76 | 2.20 | 1638 | 649 | 35 | 0.15 | 75 | 63 | 中 |
M26 | 石马山3#沟 | 0.67 | 1.91 | 1497 | 706 | 15 | 0.05 | 80 | 99 | 低 |
M27 | 石马山2#沟 | 0.61 | 2.20 | 1643 | 673 | 18 | 0.05 | 59 | 92 | 低 |
M28 | 佛堂坝沟 | 33.86 | 9.87 | 2479 | 196 | 2470 | 2.63 | 65 | 86 | 高 |
M29 | 石马山1#沟 | 1.30 | 2.44 | 1659 | 612 | 42 | 0.11 | 80 | 80 | 中 |
M30 | 彻底关沟 | 16.51 | 7.91 | 2362 | 239 | 1049 | 1.14 | 100 | 76 | 高 |
M31 | 高家沟 | 3.59 | 3.21 | 1832 | 485 | 767 | 0.34 | 52 | 110 | 高 |
M32 | 罗圈湾沟 | 28.05 | 9.62 | 2448 | 198 | 2054 | 2.31 | 70 | 114 | 高 |
M33 | 张坪岩沟 | 0.67 | 1.50 | 1437 | 863 | 21 | 0.09 | 35 | 93 | 中 |
M34 | 银杏坪沟 | 7.00 | 4.72 | 2037 | 345 | 505 | 0.66 | 48 | 78 | 高 |
M35 | 苏坡店上沟 | 0.42 | 1.47 | 1207 | 738 | 7 | 0.04 | 120 | 118 | 低 |
M36 | 苏坡店沟 | 2.84 | 3.29 | 1633 | 397 | 42 | 0.22 | 120 | 84 | 中 |
M37 | 野牛沟 | 24.38 | 10.57 | 3016 | 201 | 1655 | 1.65 | 105 | 91 | 高 |
M38 | 一碗水沟 | 3.46 | 3.36 | 1437 | 233 | 90 | 0.32 | 72 | 45 | 中 |
M39 | 磨子沟 | 7.15 | 5.53 | 2652 | 384 | 769 | 0.59 | 58 | 77 | 高 |
M40 | 下坪沟 | 1.48 | 2.66 | 2076 | 702 | 47 | 0.14 | 108 | 90 | 中 |
M41 | 上坪沟 | 0.68 | 2.02 | 1634 | 686 | 17 | 0.07 | 90 | 98 | 中 |
M42 | 马家坪沟 | 2.29 | 2.56 | 1782 | 627 | 267 | 0.24 | 70 | 80 | 高 |
M43 | 太平驿沟 | 26.19 | 9.18 | 2290 | 200 | 912 | 2.28 | 85 | 77 | 高 |
M44 | 清水沟 | 3.85 | 4.11 | 1596 | 311 | 3 | 0.42 | 108 | 95 | 低 |
M45 | 清水店沟 | 39.04 | 13.56 | 3201 | 182 | 1660 | 2.80 | 97 | 70 | 高 |
M46 | 关山沟 | 2.04 | 2.71 | 1871 | 621 | 122 | 0.56 | 65 | 85 | 高 |
M47 | 小磨子沟 | 2.74 | 2.81 | 1762 | 502 | 319 | 0.53 | 60 | 92 | 高 |
M48 | 窝氹沟 | 0.64 | 1.54 | 1000 | 563 | 15 | 0.11 | 60 | 79 | 低 |
M49 | 无音寺沟 | 5.34 | 4.47 | 1656 | 289 | 206 | 0.75 | 38 | 75 | 中 |
M50 | 白家林沟 | 0.63 | 1.78 | 1083 | 548 | 16 | 0.09 | 40 | 82 | 低 |
M51 | 老街沟 | 0.48 | 1.59 | 1087 | 614 | 6 | 0.06 | 40 | 95 | 低 |
M52 | 老街南沟 | 0.51 | 1.75 | 1091 | 559 | 12 | 0.06 | 40 | 84 | 低 |
M53 | 白家林南沟 | 0.66 | 1.57 | 1011 | 559 | 10 | 0.15 | 40 | 93 | 低 |
M54 | 烧房沟 | 0.65 | 1.90 | 1117 | 529 | 26 | 0.09 | 70 | 92 | 低 |
M55 | 红椿沟 | 5.20 | 3.77 | 1289 | 274 | 213 | 0.79 | 70 | 88 | 高 |
The authors have declared that no competing interests exist.
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