Analysis on disaster characteristics and prevention measures of the post-fire debris flow in Dianchichang gully, Xichang of Sichuan Province
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摘要:
火后泥石流是一种裹挟大量松散物质的特殊性洪流，与林火密切相关，其成灾特征与常规泥石流差异显著，因此常规泥石流的防治经验对其不完全适用。西昌“3·30”火灾后，火烧迹地火后泥石流频发，严重威胁当地人民生命财产安全。研究火后泥石流的成灾特征，并针对性提出综合防治措施是必要且迫切的。文中以四川省凉山州西昌市新村电池厂沟为研究对象，分析了火烧迹地及流域特征，研究了火后泥石流成灾特征并提出相应的防治措施。结果表明，电池厂沟过火面积占总面积的83.37%，严重火烧区占33.47%，地表灰烬层广泛堆积于坡面，松散物源中坡面物源占69.83%。火后泥石流表现出频发性：首次暴发于火后一个月左右，首个雨季累计暴发5次；且泥石流起动降雨阈值低，易发性激增。据此，对该沟提出相应的防治措施：短期应急（坡面枯木清理、植被恢复、简易谷坊坝）；中期治理（沟内拦砂坝辅以坝后沉沙池）；长期预防（森林防火、植被保护、预警避险）。短期、中期方案已在电池厂沟实施，工程竣工后至今，综合治理效果得到了初步检验，可为今后火后泥石流防治提供参考。
Abstract:Post-fire debris flow is a special torrent containing a large amount of loose material, which is closely related to forest fire. Its characteristics are significantly different from the conventional debris flow. Therefore, conventional debris flow prevention experience is not completely applicable to it. After the fire that broke out on March 30 in Xichang, debris flow occurred frequently in burned area, seriously threatening the safety of local people's lives and property. It is necessary and urgent to study the characteristics of debris flow after fire and put forward comprehensive prevention and control measures. This study takes Dianchichang gully in Xichang, Liangshan Yi Autonomous Prefecture, Sichuan Province as a typical case. Analyzed the characteristics of burned area and watershed. Studied the characteristics of post-fire debris flow disaster. And proposed the corresponding prevention and control measures. The results show that the burned area covered 83.37%, seriously burned areas accounted for 33.47%, resulting in widely spread ash layer. Slope provenance accounted for 69.83%. Post-fire debris flow occurred one month after the forest fire, and a total of 5 debris flows occurred in the first rainy season. Moreover, the threshold of debris flow starting rainfall is small and the occurrence of debris flow increases rapidly. The post-fire debris flows in the study site are characterized by high frequency and sudden occurrence. Accordingly, the corresponding prevention and control measures were propound as follows. The rapid emergency treatment measures include clarifying dead wood on slope surface, vegetation restoration, and building of simple barrier dams in gully. Medium-term governance measures are debris dams in gully and grit basins. And long-term prevention measures are a combination of forest fire prevention and vegetation protection. This scheme has been implemented in Dianchichang gully. Since the completion of these projects, the effects of comprehensive treatments have been preliminarily proved effective for the mitigation of this type of special debris flow. It can provide reference for post-fire debris flow prevention in the future.
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表 1 电池厂沟火烧迹地不同火烈度判别特征
Table 1. Discriminant characteristics of different fire intensity in burned area in Dianchichang gully
火烈度 特征 dNBR值 面积/km2 未火烧 火烧前后地表覆盖物无变化 <0.12 − 轻度火烧 超过50%的枯枝落叶完全烧毁 0.12～0.33 5.40 中度火烧 大部分枯枝落叶被烧毁，但是大部分粗可燃物未完全烧毁 0.33～0.48 9.57 严重火烧 枯枝落叶和粗可燃物均被完全烧毁，地表为灰烬层覆盖 >0.48 12.61 
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表 2 电池厂沟泥石流物源统计表
Table 2. Statistics of different sources of debris flow in Dianchichang gully
物源类型 总体积/104 m3 体积分数/% 沟道物源 1.90 11.84 坡面物源 11.20 69.83 滑坡物源 2.94 18.33
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[1] 胡卸文, 金涛, 殷万清, 等. 西昌市经久乡森林火灾火烧区特点及火后泥石流易发性评价[J]. 工程地质学报,2020,28(4):762 − 771. [HU Xiewen, JIN Tao, YIN Wanqing, et al. The characteristics of forest fire burned area and susceptibility assessment of post-fire debris flow in Jingjiu township, Xichang City[J]. Journal of Engineering Geology,2020,28(4):762 − 771. (in Chinese with English abstract)
[2] 王严, 胡卸文, 杨瀛, 等. 火烧迹地土壤斥水性和渗透性变化特性[J]. 水文地质工程地质,2019,46(6):40 − 45. [WANG Yan, HU Xiewen, YANG Ying, et al. Research on the change in soil water repellency and permeability in burned areas[J]. Hydrogeology & Engineering Geology,2019,46(6):40 − 45. (in Chinese with English abstract)
[3] CANNON S, RENEAU S. Conditions for generation of fire-related debris flows, Capulin Canyon, New Mexico[J]. Earth Surface Processes and Landforms,2000,25:1103 − 1121. doi: 10.1002/1096-9837(200009)25:10<1103::AID-ESP120>3.0.CO;2-H
[4] JOSEPH E, AL E. Compilation of data relating to the erosive respose of 606 recently-burned basins in the Western U. S. [R]. U. S: U. S. Geological Survey Open-File, 2005.
[5] 胡卸文, 王严, 杨瀛. 火后泥石流成灾特点及研究现状[J]. 工程地质学报,2018,26(6):1562 − 1573. [HU Xiewen, WANG Yan, YANG Ying. Research actuality and evolution mechanism of post-fire debris flow[J]. Journal of Engineering Geology,2018,26(6):1562 − 1573. (in Chinese with English abstract)
[6] DENNIS M S, JOSEPH E G, JASON W K. Objective definition of rainfall intensity-duration thresholds for post-fire flash floods and debris flows in the area burned by the Waldo canyon fire, Colorado, USA[M]//Engineering Geology for Society and Territory-Volume 2. Cham: Springer International Publishing, 2015: 621 − 624.
[7] 张绍科, 胡卸文, 王严, 等. 四川省冕宁县华岩子沟火后泥石流成灾机理[J]. 中国地质灾害与防治学报,2021,32(5):79 − 85. [ZHANG Shaoke, HU Xiewen, WANG Yan, et al. Disaster mechanism of post-fire debris flow in Huayanzi gully, Mianning County, Sichuan Province[J]. The Chinese Journal of Geological Hazard and Control,2021,32(5):79 − 85. (in Chinese with English abstract)
[8] 高相波, 李丽慧. 热水河流域典型泥石流灾害成因机制与协同防治研究[J]. 工程地质学报,2020,28(5):1039 − 1048. [GAO Xiangbo, LI Lihui. Initiation mechanism of typical debris flow hazard in hot water river basin and synergetic prevention study[J]. Journal of Engineering Geology,2020,28(5):1039 − 1048. (in Chinese with English abstract)
[9] 陈晓清, 崔鹏, 赵万玉. 汶川地震区泥石流灾害工程防治时机的研究[J]. 四川大学学报(工程科学版),2009,41(3):125 − 130. [CHEN Xiaoqing, CUI Peng, ZHAO Wanyu. Optimal timing for the control of debris flow in Wenchuan earthquake area[J]. Journal of Sichuan University (Engineering Science Edition),2009,41(3):125 − 130. (in Chinese with English abstract)
[10] 胡卸文, 韩玫, 梁敬轩, 等. 汶川地震灾区泥石流若干关键问题[J]. 西南交通大学学报,2016,51(2):331 − 340. [HU Xiewen, HAN Mei, LIANG Jingxuan, et al. Some key problems on debris flow in Wenchuan earthquake area[J]. Journal of Southwest Jiaotong University,2016,51(2):331 − 340. (in Chinese with English abstract) doi: 10.3969/j.issn.0258-2724.2016.02.012
[11] FOX D M. Evaluation of the efficiency of some sediment trapping methods after a Mediterranean forest fire[J]. Journal of Environmental Management,2011,92(2):258 − 265. doi: 10.1016/j.jenvman.2009.10.006
[12] DE GRAFF J V. Improvement in quantifying debris flow risk for post-wildfire emergency response[J]. Geoenvironmental Disasters,2014,1:5. doi: 10.1186/s40677-014-0005-2
[13] DEWOLFE V G, SANTI P M, EY J, et al. Effective mitigation of debris flows at Lemon Dam, La Plata County, Colorado[J]. Geomorphology,2008,96(3/4):366 − 377.
[14] 王严, 胡卸文, 金涛, 等. 火后泥石流形成过程的物源启动模式研究[J]. 工程地质学报,2019,27(6):1415 − 1423. [WANG Yan, HU Xiewen, JIN Tao, et al. Material initiation of debris flow generation processes after hillside fires[J]. Journal of Engineering Geology,2019,27(6):1415 − 1423. (in Chinese with English abstract)
[15] 王晓莉, 王文娟, 常禹, 等. 基于NBR指数分析大兴安岭呼中森林过火区的林火烈度[J]. 应用生态学报,2013,24(4):967 − 974. [WANG Xiaoli, WANG Wenjuan, CHANG Yu, et al. Fire severity of burnt area in Huzhong forest region of Great Xing'an Mountains, Northeast China based on normalized burn ratio analysis[J]. Chinese Journal of Applied Ecology,2013,24(4):967 − 974. (in Chinese with English abstract)
[16] 任云, 胡卸文, 王严, 等. 四川省九龙县色脚沟火后泥石流成灾机理[J]. 水文地质工程地质,2018,45(6):150 − 156. [REN Yun, HU Xiewen, WANG Yan, et al. Disaster mechanism of the Sejiao post-fire debris flow in Jiulong County of Sichuan[J]. Hydrogeology & Engineering Geology,2018,45(6):150 − 156. (in Chinese with English abstract)
[17] 吴超, 徐伟恒, 肖池伟, 等. 滇中地区典型火烧迹地恢复率动态变化及其影响因子[J]. 资源科学,2021,43(12):2465 − 2474. [WU Chao, XU Weiheng, XIAO Chiwei, et al. Dynamic change of recovery ratios and influencing factors of typical post-fire burn areas in central Yunnan Province[J]. Resources Science,2021,43(12):2465 − 2474. (in Chinese with English abstract) doi: 10.18402/resci.2021.12.09
[18] 刘鲁光, 朱兆棋, 陈曦, 等. 喜德县中坝村火烧迹地植被恢复初期优势种生态位与种间联结[J]. 西部林业科学,2022,51(1):110 − 117. [LIU Luguang, ZHU Zhaoqi, CHEN Xi, et al. Ecological niche and interspecific association of dominant species in the initial stage of vegetation restoration in Zhongba Village of Xide County[J]. Journal of West China Forestry Science,2022,51(1):110 − 117. (in Chinese with English abstract)
[19] 陈曦, 杨丹, 胡翠华, 等. 西昌市泸山景区森林火灾后植被恢复现状[J]. 林业科技通讯,2020(4):13 − 17. [CHEN Xi, YANG Dan, HU Cuihua, et al. Vegetation restoration after forest fire in Lushan Scenic area, Xichang City[J]. Forest Science and Technology,2020(4):13 − 17. (in Chinese with English abstract)
[20] 殷万清, 金涛, 胡卸文, 等. 喜德县中坝村火后泥石流发育特征及预警避险[J]. 中国地质灾害与防治学报,2021,32(3):61 − 69. [YIN Wanqing, JIN Tao, HU Xiewen, et al. Study on the development characteristics of post-fire debris flow and its early warning risk aversion in Zhongba Village, Xide County[J]. The Chinese Journal of Geological Hazard and Control,2021,32(3):61 − 69. (in Chinese with English abstract)
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