基于灰色关联度和联系数耦合的农业旱灾脆弱性评价和诊断研究

Evaluation and Diagnosis of Agricultural Drought Vulnerability Based on Grey Correlation and Connection Number Coupling

农业旱灾脆弱性评价和诊断是科学防范农业旱灾风险的关键,在区域农业旱灾风险调控实践中具有重要作用。为定量评价区域农业旱灾脆弱性强弱程度、识别影响其强度变化的主要指标,通过改进差异度系数的计算方法,建立了基于灰色关联度和联系数耦合的区域农业旱灾脆弱性评价模型,对区域农业旱灾脆弱性进行动态评估,并根据此模型提出了基于五元减法集对势的区域农业旱灾脆弱性诊断方法,用以识别影响脆弱性的主要指标。在蚌埠市的应用结果表明:蚌埠市农业旱灾脆弱性评价等级从2001-2003年的超3级水平改善到2004-2010年的3级水平,农业旱灾脆弱性呈减弱趋势,农业系统对干旱灾害的承受能力呈逐年提升趋势;通过诊断模型识别出影响蚌埠市农业旱灾脆弱性的主要指标有农民人均GDP、单位耕地面积农机动力、农业万元GDP用水量和单位农业增加值耗水量,其中单位农业增加值耗水量与农业旱灾脆弱性的相关性最大。这些结果可为区域农业旱灾风险调控提供科学依据,对促进农业旱灾风险定量研究具有重要意义。

The assessment and diagnosis of agricultural drought vulnerability is the key to control of regional agricultural drought risk scientifically. Meanwhile, it plays an important role in the practices of regional agricultural drought risk control. To quantitatively evaluate the regional agricultural drought vulnerability and identify the main indicators which affect the vulnerability changes, a regional agricultural drought vulnerability evaluation model based on grey correlation and connection number is established by improving the calculation method of the difference coefficient I. Furthermore, a method for regional agricultural drought vulnerability diagnosis based on five-variables set pair potential is proposed to identify the main influence factors. The results show that the evaluation grade of regional agricultural drought vulnerability in Bengbu City had been improved from the grades which is greater than 3 to the grade 3, it reflected that the ability of agricultural system to carry drought disaster had been improved from 2001 to 2010. The main indicators which affect the agricultural drought vulnerability in Bengbu City were per capita income of farmers, agricultural machinery power per unit cultivated area, water consumption of per ten thousand yuan GDP and unit added value of agricultural water consumption. Moreover, the relationship between the unit added value of agricultural water consumption and the agricultural drought vulnerability in Bengbu City was the most significant. These results can provide a scientific foundation for the control of regional agricultural drought risk and promote the quantitative study of agricultural drought risk.