农业旱灾形成过程中的承灾体脆弱性分析——以湖南鼎城为例

Analysis of hazard-affected body's vulnerability in formative process of agricultural drought: a case study on Dingcheng District in Hunan

农业旱灾的形成是降水不足或不均与农业生产系统脆弱性共同作用的结果,承灾体脆弱性的高低会起到“放大”或“缩小”灾情的作用,因此降低承灾体的脆弱性是抗灾减灾的主要和有效途径。选择湖南省鼎城区为研究区,通过分析灾前期—灾中期旱灾的形成过程及其与承灾体脆弱性的关系,分别针对轻度干旱和中重度干旱建立了评价指标体系,采用加权求和法对水田-水稻农业生产系统的脆弱性进行了评价。结果表明,该区的承灾体脆弱性分布存在一定的区域差异,脆弱度由高至低排序为西北岗地区、南部低山/丘陵区、中部平原/岗地区、东北湖/平原区,这一分析结果与实际灾情的分布规律基本一致。通过分析脆弱性分布规律和变化原因,发现地形和灌溉分别是影响灾前期和灾中期承灾体脆弱性的最重要因素,进而提出了具体的减灾防灾建议。

Agricultural drought-hazard is the result of a combination of precipitation shortage or unevenness and the vulnerability of agricultural production system.However,the degree of vulnerability can magnify or lessen disaster losses.As a result,to alleviate the vulnerability of hazard-affected body is a principal and effective way to fight against calamities and to reduce the losses.Taking Dingcheng District in Hunan as a research region,and analyzing the relation between forming process of drought and the vulnerability of hazard-affected body,the assessment indices system is established for light drought and moderate-severe drought,and the vulnerability assessment of paddy field and rice agricultural production system is carried out with weighting method.The analytical result,which is in line with hazard losses,shows that there is a regional regulation in vulnerability distribution,with the sequence of vulnerability degree from high to low:mountain area in southwest,hilly area in south,lake/mountain area in the middle,lake/plain area in southeast.Through analyzing the vulnerability distribution regulation and the reasons of its changes,it was found that terrain and irrigation are the major factors that influence vulnerability in prophase and anaphase of the disaster.Finally,the specific advices to reduce and prevent disasters are put forward.