基于水文响应单元的泥石流灾害易发性分区方法

摘要

以水文响应单元和栅格单元为基础评价单元,运用因子贡献率法和信息量法两种评价模型对安宁河流域进行泥石流灾害易发性评价.研究结果表明,在流域尺度范围内,水文响应单元能够更好体现区域中的微观综合地貌特征,切合区域整体性描述;基于水文响应单元的易发性分区不仅与历史泥石流实际分布情况的契合度较高,而且数学模型方法适应效率较高和区内孕灾条件体现更为明显.由此,建立基于水文响应单元泥石流灾害易发性分区对探求流域尺度范围内泥石流灾害易发性分区方法与评价制图是一个有益的尝试与拓展,可为制定减灾防灾决策提供科学参考.%In this article,an improved method with combination of grid cell and hydrological response unit as basic evaluation unit was introduced into our improved model to assess the susceptibility of debris flow at the Anning River basin.Information value method and contribute rate method were adopted in the susceptibility assessment model.The results confirmed that at watershed scale,susceptibility zones developed from this assessment model with hydrological response unit not only showed high consistence with the actual debris flow distribution but also agreed better with the regional geographical description as well as the micro geomorphologic characteristics of such area.In addition,the improved assessment model showed better calculation efficiency and well reflected the hazard fostering conditions.Thus,the proposed method is an effective improvement of debris flow susceptibility assessment at watershed scale and it also provide scientific support to disaster reduction and prevention.