基于地貌指数的汶川地震灾区单沟泥石流总量计算方法

Method of Calculating Single Gully Debris-flow Volume in Wenchuan Earthquake Area Based on Morphometric Index

现行的泥石流总量计算方法普遍存在计算参数较难获取或难以精确获取的问题,加上汶川地震灾区沟谷内分布大量的由崩塌、滑坡体等形成的固体松散物质;所以多数泥石流总量计算公式在汶川震区存在局限性。参考适用于以崩塌、滑坡体为主要物源的泥石流总量计算公式;分析研究区范围内地形地貌发育状态与降雨因素及其地质条件之间的影响关系;将地貌指数(Strahler积分)应用于泥石流总量计算,尝试解决缺乏降雨数据情况下泥石流总量计算问题。根据"8.13"四川清平群发性泥石流数据初步回归分析得到适合于汶川震区的泥石流总量计算模型。

Most available equations for estimating a maximum debris-flow volume have the limitation in requiring uncertain input parameters. In addition, landslips and landslides that occurred in the debris-flow source area of the Wenchuan earthquake zone contributed extensively to the debris-flow volume. Most equations have the limitation in this area. This study is based on an equation that is fit for debris-flow in earthquake zone. The relationships among morphometrie condition, rain and other geological conditions are analyzed. The morphometric index （Strahler Integration） is tentatively used to calculate debris-flow volume when rain condition data are unavailable. A model suitable for calculation of debris-flow volume of Wenchuan earthquake zone is worked out based on regression analysis of the data of group debris-flows in Qingping Town, Mianyuan River Upstream, Sichuan.