南水北调受水区干旱灾害风险评估方法探讨

Drought Risk Assessment in the South-to-North Water Transferred Areas

南水北调工程的受水区为黄淮海流域,干旱问题已经成为该区域经济和社会发展的瓶颈,因此有必要对受水区内的干旱风险做出准确评估。区域干旱风险可以理解为区域内暴露于干旱下的承灾体,在外部致灾因子扰动下,由于自身的脆弱性,所遭受损失的可能性及可能的损失程度的大小。区域干旱风险评估的任务是明晰发生干旱时暴露于干旱下各个部门和社会生活的各个方面,确定引发干旱的自然致灾因子,分析承灾体的脆弱性,预测干旱造成的影响和损失,并通过数学方法合理量化风险的大小,同时确定造成各部门、地区和人口风险的主要原因,即干旱风险的主要影响因素,从而寻求降低风险的有效途径。现以南水北调某一特定受水区域为研究对象,分析了干旱灾害的成灾机理,对干旱致灾因子的危险性及承灾体的脆弱性进行了讨论,提出相应的计算公式,建立了针对特定区域的干旱灾害风险评估模式,对干旱灾害风险提出了量化的方法。并结合南水北调受水区济南市的实际情况对本文提出的方法进行了应用和验证,实践证明该风险评估模式有一定的科学性和应用价值。

With the growth of the city, drought has become the serious element threatening the harmonious development of the society and environment. Drought is not only a nature phenomenon but a social problem referred to many aspects, such as industry, agriculture, daily lives. So how to reduce drought effects and loss has become a hot issue. The paper presented a new method for drought risk assessment. Drought risk assessment is the foundation of risk management and alleviation of drought disaster. Effective measures can be taken to reduce drought risk to avoid the extreme disaster. On the comprehensive analysis of the evocable factor of drought, the vulnerability of drought disaster acceptor and the mechanism of drought disaster, the method of drought risk assessment were established to reflect the possibility and degree of drought disaster.