防灾优先性是减灾决策的组成部分。阐述了防灾优先性与减灾优先性的关系及其在灾害评价中的地位和作用 ,提出了适合我国国情的泥石流防灾优先性评价模式和计算公式 ,并应用于四川阿坝州。研究成果可为各级政府和灾害管理部门制定泥石流减灾规划和防治政策提供科学基础和决策依据 ,亦可为其它灾害类型的防灾优先性评价提供参考模式

Debris flow prevention priority (DFPP) is a part of debris flow mitigation priority (DFMP) 1 DFMP is defined as in a given area and a period of time , the degree of priority for reduction of debris flows should be considered DFMP is the sum of DFPP and debris flow relief priority (DFRP) . Hence DFRP is an important component for hazard assessment DFPP is directly related to regional hazard degree of debris flow , population density and regional development index It is quantitatively expressed as P = H ×E ×M where P is DFPP(10 000 yuan/ km2) ; H is regional hazard degree of debris flow (0- ) ; E is population density (person/km2) ; M is per capita GDP(10 000 yuan/ person) H is a function of twelve variables relevant to natural characteristics of debris flow. The primary factor is dist ribution density of debris flow , the secondary factors are involved in environmental background , including geological , geographic, meteorological and climatic factors1 Detailed findings are available in previous researches. E indicates the importance of people in the given region1 The more the population density , the more important the region. M represents the situation of development in the region1 The higher the per capita GDP , the more developed the region , and the more worthy to be prevented f rom natural hazards. Practice of this method in Aba Prefecture of Sichuan Province has demonst rated that it is significant and feasible1 Assessment of DFPP could provide scientific references and decisions on debris flow management and master plan for policy makers of government agents. Furthermore , assessment of DFPP could provide assessment mode for other kinds of natural hazards , so as to more widely popularize this methodology in the other part s of China.