基于粗糙集理论的泥石流易发性综合评判模型

Debris Flow Lability Comprehensive Evaluation Model on Rough Set Theory

泥石流灾害易发性判断是泥石流灾害性评价的重要组成部分,快捷、准确的评判对人类工程活动有着重要的指导意义。众所周知,流域中,形貌、地质、水文三大条件对泥石流灾害起决定性作用,是泥石流易发性的主要影响因素。这里基于对泥石流灾害的机理认识,将泥石流易发性分为高易发、中易发、低易发、不易发4个等级,在充分考虑泥石流灾害易发性影响因素贡献的基础上,给出各因素等级的确定标准,运用粗糙集理论获取各级评价指标的相对重要度,再依据专家经验确定主观权重,结合相对重要度和主观权重确定各因素的综合权重,进而利用模糊数学中多级模糊评判的理论和方法,建立了一种新的泥石流易发性多级模糊综合评判模型,并以陕西省凤县5条泥石流沟为例进行模型验证,结果表明这5条泥石流沟易发性从低到高的排序为:吴家沟泥石流沟、三台山泥石流沟、后沟泥石流沟、银铜梁泥石流沟、寺沟泥石流沟,结果与实际吻合良好。

The judgment of debris flow disaster liability is the important part of the debris flow disaster evaluation,and fast and accurate evaluation has important guiding significance of human engineering activity.As all as we know,topography and geomorphology,geological and hydrological conditions play a decisive role in the debris flow disaster,and are the main influence factors of debris flow lability.Based on mechanism of debris flow disasters,the debris flow lability can be divided into high lability,middle lability,low lability and not lability.Based on the full consideration of the contributions on debris flow lability factors,the factors′determine standard was given,the relative important degree of each evaluation indexes was obtained according to the rough set theory,then based on expert experience method a subjective weight was determined,the comprehensive weight was determine by combining with the relative important degree and subjective weight,then,a new kind of debris flow lability comprehensive evaluation model of multilevel fuzzy assessment was set up based on the theory and method of fuzzy mathematics on multilevel fuzzy assessment,5debris flow gullies of Fengxian,Shaanxi were taken as the example to verify the model.The results show that the debris flow gully liability in 5gullies follows the order of Wujiagou,Santaishan watershed,Hougou catchment,Yintongliang catchment,Sigou catchment.The results are in good agreement with the actual situation.