泥石流是地貌灾害的一种主要类型，泥石流灾害损失目前还无法准确统计，其一是因为对灾害损失的统 计还没有分灾种细化，往往是按大类例如地质灾害甚至是按总类自然灾害来统计；其二是因为灾害损失统计也即 灾情定量评估本身还存在一些科学技术问题尚未解决。灾害损失中的直接经济损失评估只是技术问题，而间接经 济损失评估不仅涉及到技术问题，更重要的是尚有一些科学问题仍未解决。因此，目前还没有一种普遍认同的灾害 间接经济损失评估方法。本文提出了两种方法，调查分析法：理论上可行，操作上困难，实际上只是一种设计方案； 比例系数法：操作上可行，经验成分多，仍然是一种比较粗略的方法。就目前灾害研究水平和防灾减灾实际需要来 考虑，比例系数法仍不失为一种有实用价值的灾害间接经济损失的评估方法。

Debris flow is one of the geomorphic hazards. The economic losses caused by debris flows are not yet accounted precisely at present. One of causes is the statistics is not specified for each kind of disasters by different type of natural hazards; another cause is the problems of disaster loss statistics, i.e., quantitative disaster loss estimation have not been solved yet till now. Among the disaster losses, the direct economic loss estimation depends on technical method; while the indirect economic loss estimation depends not only technical supports but also scientific bases. Therefore, there is not acknowledged method for the quantitative estimation of indirect economic losses of disasters. The present paper proposes two estimation methods: one is survey analysis, and another is proportional coefficient. The former is feasible in theory but unfeasible in actuality, and is only a scheme; the latter is practicable but empirical, and is only a crude estimation. Considering the needs of disaster reduction and mitigation currently, the method of proportional coefficient for estimation of indirect economic losses of disasters is recommended.