川西山区泥石流灾害风险评价
文献类型：学位论文
| 作者 | 陈宜娟 |
| 学位类别 | 硕士 |
| 答辩日期 | 2007 |
| 授予单位 | 中国科学院水利部成都山地灾害与环境研究所 |
| 授予地点 | 成都 |
| 导师 | 刘希林 |
| 关键词 | 川西山区 泥石流 风险评价 风险区划 |
| 学位专业 | 自然地理学 |
| 中文摘要 | 川西山区地处青藏高原和四川盆地的过渡地带，是泥石流的易发区，泥石流灾害严重危害着人民的生命财产安全并制约着当地的社会经济发展，加强泥石流灾害的风险评价和管理对于防灾减灾具有重要意义。 论文以此为着眼点，在大量相关文献阅读和资料收集的基础上，完成了以下工作：①对川西山区5个市（州）以县市为评价单元的泥石流风险度评价；②用泥石流沟分布面密度替代点密度，对是否改善现行泥石流危险度多因子评价结果进行了尝试；③在川西山区各县市泥石流风险度评价结果的基础上，进行了泥石流风险区划和制图。 上述工作得出了如下主要结论： （1）在区域泥石流危险度评价中，用“泥石流沟分布面密度”代替“泥石流沟分布点密度”，提出了相应的分段赋值函数，由此得到川西山区各县市泥石流危险度评价结果：各县市面积加权平均后的泥石流危险度为0.51，整体上属于泥石流中度危险区；区内5个市（州）面积加权平均后泥石流危险度由高到低依次为攀枝花市(0.74)、凉山州(0.71)、雅安市(0.60)、阿坝州(0.44)和甘孜州(0.38)。与点密度评价结果相比，最大绝对差值为0.16(昭觉县)，最小绝对差值为0（共11个县市），平均绝对差值为0.04；最大相对误差24.53%（丹巴县），最小相对误差0%（共11个县市），平均相对误差为6.49%。 （2）根据现有的区域泥石流易损度评价模型，计算出川西山区各县市的泥石流易损度，进行易损度分区。各县市的泥石流易损度集中在0.49~0.67之间，各县市面积加权平均后的泥石流易损度为0.55，研究区整体属于泥石流中度易损区；区内5个市（州）的泥石流易损度由高到低依次为凉山州(0.57)、攀枝花市(0.56)、雅安市(0.55)、甘孜州(0.55)和阿坝州(0.54)。 （3）在区域泥石流危险度和易损度评价的基础上，进行了泥石流风险评价，分别得出了基于泥石流沟分布点密度和面密度的川西山区各县市泥石流风险评价结果。5个市（州），用泥石流沟点密度评价得出的面积加权平均后的泥石流风险度由高到低依次为凉山州(0.40)、攀枝花市(0.39)、雅安市(0.35)、甘孜州(0.26)和阿坝州(0.23)；用泥石流沟面密度评价得到的排序依次为攀枝花市(0.42)、凉山州(0.40)、雅安市(0.33)、阿坝州(0.24)和甘孜州(0.21)。总体而言，研究区整体上属于泥石流中等风险区，其风险和效益并存，在开发时应考虑降低风险的措施并加强风险管理；其中凉山彝族自治州和攀枝花市是泥石流灾害高风险区，是投资开发的谨慎区域，应对已有财产采取必要措施予以防范，进行风险转移。（4）通过两种评价指标所得风险评价结果的分析对比，用泥石流沟分布面密度评价得出的结果并没有明显改善评价的精度，对用泥石流沟分布点密度的评价结果改变很小。从而反证了用点密度进行区域泥石流危险度计算的可靠性和合理性。由于点密度方法具有获取资料较容易、计算较简便、工作量较小等优点，因而具有更为便利的推广价值。（5）将基于泥石流沟分布点密度计算得出的区域泥石流危险度、易损度和风险评价结果以县市为基本单元进行泥石流风险区划和制图，得到了川西山区泥石流风险区划图。其中，泥石流灾害高风险县市24个，包括新龙县、金川县、西昌市、德昌县、会理县、会东县、宁南县、普格县、布拖县、金阳县、昭觉县、喜德县、冕宁县、越西县、甘洛县、美姑县、雷波县、攀枝花市东西区、盐边县、米易县、雨城区、荥经县、汉源县和天全县；中等风险县市33个，低风险县市2个，极低风险县市1个。 |
| 英文摘要 | The mountain area of western Sichuan is located in the transitioned region from Sichuan basin to Qinghai-Tibet Plateau, in which debris flows occur frequently. Debris flow hazards highly have been threating the safety of people’s lifes and property, and hamper the economic development in this area. Debris flow risk assessment and management are of great significance for reduction and prevention of debris flow disasters. Based on a number of related documents and literatures, this paper has done the following work: 1) assessing the debris-flow risk for all of counties that belongs to five prefectures in the mountain area of western Sichuan; 2) checking whether it can improve the present Multiple Factor Composite Assessment Model for regional debris flow hazard by substituting areal distribution density of debris flow gullies for their point distribution density; 3) providing the debris flow risk zonation map.The study comes to the following conclusions: (1) In regional debris flow hazard assessment, by replacing ‘areal distribution density’ of debris flow gullies with their ’point distribution density ’ and putting forward corresponding transformation functions, we get the results of debris flow hazard assessment of each county in this area: the debris flow hazard degree is 0.51 after weighted average by using every county’s area, belonging to moderate hazard zone; for the five prefectures, the descending order of the debris flow hazard degree is Panzhihua(0.74), Liangshan(0.71), Ya’an(0.60), A’ba(0.44) and Ganzi(0.38). Compared to the result of the point density, the maximum absolute difference between the two results is 0.16 for the County of Zhaojue, the minimum is zero for 11 counties and the mean absolute difference is 0.04; the maximum relative error is 24.53% for the County of Danba, the minimum relative error is zero for 11 counties and the mean relative error is 6.49%.(2) Based on the present debris flow vulnerability degree assessment model, the debris flow vulnerability degrees of these counties have been calculated and used to zone the vulnerability zonation. The result shows the debris flow vulnerabilities in this area range from 0.49 to 0.67. After weighted average with every county’s area, it is 0.55. Therefore, the study area belongs to moderate hazard zone; the descending order with respect to the debris flow vulnerability degree is Liangshan(0.57), Panzhihua(0.56), Ya’an(0.55), Ganzi(0.55) and A’ba(0.54).(3) On the basis of the regional debris flow hazard assessment and the vulnerability degree assessment, the risk evaluation of debris flow has been analyzed, and the results have been given respectively based on the areal density and the point density. The results of the point density show the order of risk evaluation of debris flow for each prefecture from very high to lowest is Liangshan(0.40), Panzhihua(0.39), Ya’an(0.35), Ganzi(0.26) and A’ba(0.23), while the order based on the areal density for each prefecture is Panzhihua(0.42), Liangshan(0.40), Ya’an(0.33), A’ ba(0.24) and Ganzi(0.21). As a whole, the study area lies in moderate hazard zone, so the area faces not only risk but also benefit, by taking measures of reducing risk and strengthening risk management during developments. Among the prefectures, Liangshan and Panzhihua belong to the high hazard level, are cautious regions for investment, too. It is necessary to protect the present property by taking precaution measures and transfer risk in the areas.(4) With the comparison of the two indexes, the results based on the areal density is not significant effect on the assessment precision and show a little difference from those results based on the point density, which in turn prove that the calculation method of regional debris flow hazard degree by using the point density is reliable and reasonable. Meanwhile, because of advantages of the point density method such as convenient data acquisition, simple calculation and less effort, the method is worth of application to other regions. (5) The debris flow risk zoning and mapping with the counties as elementary unit were made based on the regional debris flow hazad degree, vulnerability degree and risk assessment calculated by the point density. The debris flow risk map of mountain area of western Sichuan results from the zonation of each counties. The map indicates that, there are 24 high risk counties including Xinlong, Jinchuan, Xichang, Dechang, Huili, Huidong, Ningnan, Puge, Butuo, Jinyang, Zhaojue, Xide, Mianning, Yuexi, Ganluo, Meigu, Leibo, the urban region of Panzhihua,Yanbian, Miyi, Yucheng, Yingjing, Hanyuan and Tianquan; 33 moderate risk counties, 2 low risk counties and 1 very low risk country. |
| 学科主题 | 灾害学 |
| 语种 | 中文 |
| 公开日期 | 2010-10-20 |
| 分类号 | X43;P64 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/2253]  |
| 专题 | 成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前） |
| 推荐引用方式 GB/T 7714 | 陈宜娟. 川西山区泥石流灾害风险评价[D]. 成都. 中国科学院水利部成都山地灾害与环境研究所. 2007. |
入库方式： OAI收割
来源：成都山地灾害与环境研究所
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