基于GIS的汶川县地质环境安全综合评价
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摘要
汶川县内地质构造复杂,新构造运动强烈,地震活动频繁,主要地质环境问题以地质灾害为主,有崩塌、滑坡、泥石流等。在分析区内主要地质环境问题及分布特征的基础上,运用层次分析法(AHP)确定权重,采用模糊综合评判模型、综合指数模型两种方法,对汶川县地质环境安全进行综合评价。详细介绍基于GIS的评价计算流程及评价因子的提取过程。评价结果表明,地质环境对居民生产生活影响的危险等级占比为:危险性低的约占25%,危险性较低的约占20%,危险性较高的约占39%,危险性高的约占16%。对两组权重系数、两个模型下的四个评价结果进行对比分析,结果发现:1两组不同权重系数下,模糊评价法和综合指数法评价结果的双侧检验相关系数依次是0.97、0.98,属于高度显著相关,表示可以忽略人为赋权重对评价结果的主观影响;2两种不同模型下,评价结果的双侧检验相关系数依次是0.895、0.84、0.92、0.914,属于显著相关,表示不同的计算模型一定程度上影响了评价结果的准确性,在评价时要认真研究选择恰当的计算模型。
In the Wenchuan County has complex geological structure,strong neotectonic movement,frequent earthquake activities;main geological hazards have collapse,landslide and debris flow etc. Based on main geological environment problems and their distribution analysis,using analytical hierarchy process(AHP) to determine weights,through fuzzy comprehensive evaluation model method and comprehensive index model method,carried out Wenchuan County geological environment safety comprehensive assessment.The paper has introduced assessment computation procedure based on GIS and assessment factor extracting process in detail. The assessment result has shown that the hazard rating proportion of environment impact on resident production and lift: low hazard about25%,lower hazard about 20%,higher hazard about 39%,high hazard about 16%. The contrastive analysis of four assessed results under two groups of weight coefficient and two models has found that: 1 under two different groups of weight coefficient,two-sided test correlation coefficient of fuzzy evaluation method and comprehensive index method are 0.97 and 0.98 in turn,belong to highly significant correlation,thus can ignore subjective influence of artificial weights on assessed results; 2 under two different models,assessed results two-sided test correlation coefficient are 0.895,0.84,0.92,and 0.914 in turn,belong to significant correlation,thus different computation models have influenced accuracy of assessed results in a certain degree,so that the selection of computation model should be seriously studied during assessment.
In the Wenchuan County has complex geological structure,strong neotectonic movement,frequent earthquake activities;main geological hazards have collapse,landslide and debris flow etc. Based on main geological environment problems and their distribution analysis,using analytical hierarchy process(AHP) to determine weights,through fuzzy comprehensive evaluation model method and comprehensive index model method,carried out Wenchuan County geological environment safety comprehensive assessment.The paper has introduced assessment computation procedure based on GIS and assessment factor extracting process in detail. The assessment result has shown that the hazard rating proportion of environment impact on resident production and lift: low hazard about25%,lower hazard about 20%,higher hazard about 39%,high hazard about 16%. The contrastive analysis of four assessed results under two groups of weight coefficient and two models has found that: 1 under two different groups of weight coefficient,two-sided test correlation coefficient of fuzzy evaluation method and comprehensive index method are 0.97 and 0.98 in turn,belong to highly significant correlation,thus can ignore subjective influence of artificial weights on assessed results; 2 under two different models,assessed results two-sided test correlation coefficient are 0.895,0.84,0.92,and 0.914 in turn,belong to significant correlation,thus different computation models have influenced accuracy of assessed results in a certain degree,so that the selection of computation model should be seriously studied during assessment.
引文
[1]汪留洋,傅荣华,吴亚子.地质环境与地质环境评价[J]甘肃水利水电技术,2013,(1);50-53.
[2]李鸿吉.模糊数学基础及实用算法[M].北京:科学出版社,2005.
[3]四川省蜀通岩土工程公司.汶川地震灾区震后汶川县地质灾害详细调查与区划报告[R].2009.
[2]李鸿吉.模糊数学基础及实用算法[M].北京:科学出版社,2005.
[3]四川省蜀通岩土工程公司.汶川地震灾区震后汶川县地质灾害详细调查与区划报告[R].2009.
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