| 李颖,冯玉,唐伟男,任家璇.基于Copula函数的辽西地区农业气象干旱灾害分析[J].干旱地区农业研究,2018,36(2):279~287 |
| 基于Copula函数的辽西地区农业气象干旱灾害分析 |
| Analysis of agricultural meteorological drought disaster around western Liaoning Province based on Copula function |
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| DOI：10.7606/j.issn.1000-7601.2018.02.40 |
| 中文关键词: 农业气象干旱 SPI Copula函数 重现期 辽西地区 |
| 英文关键词:agricultural meteorological drought SPI Copula function return period Western Liaoning Province |
| 基金项目:辽宁省教育厅科学技术研究项目(L201683677)；辽宁师范大学青年科研项目(LS2015L011) |
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| 中文摘要: |
| 干旱作为辽西地区频发的自然灾害之一，对农业影响显著。综合考虑气象干旱灾害的多要素作用，本文基于SPI指数利用游程理论提取辽西地区1956—2014年农业气象干旱的历时和强度，在确定单变量边缘分布的基础上采用Copula函数分析干旱发生的联合概率和重现期，并以1991—2011年农作物旱灾实况为依据，探讨气象干旱重现期与作物旱灾损失之间的联系。结果显示：(1) 干旱历时和干旱强度分别符合Weibull和Gev分布，Frank-Copula适合模拟辽西地区的干旱联合分布；(2) 本区发生历时和强度双低、短历时-高强度、长历时-低强度干旱的可能性较大；(3) 高强度-短历时和低强度-长历时组合下重现期多为2—4个月，辽西多轻、中旱；(4) 1991—2011年旱灾实际重现期与理论重现期接近，表明联合重现期能更好地体现灾害发生频次；(5) 重现期低于2个月为轻度干旱，2—8个月为中度干旱，高于8个月为重度干旱，农业部门可根据联合重现期预测出的干旱等级采取有针对性的防旱抗旱措施。 |
| 英文摘要: |
| Drought is one of the frequent natural disasters of the western part of Liaoning province, and its impaction on the agriculture is very significant. Considering many elements of meteorological drought effect, in this paper, the duration and intensity of agro-meteorological drought in western Liaoning in 1956—2014 were extracted by using the run-length theory based on SPI index. On the basis of determining the univariate edge distribution, the Copula function was used to analyze the joint probability and return period of drought occurrence. Based on the actual situation of crop drought from 1991 to 2011, the relationship between the drought recovery period and crop drought loss was discussed. The results showed that: (1) the correlation between the drought duration and drought intensity was large, conformed to the Weibull distribution and Generalized Extreme Value distribution respectively, and Frank-Copula function was suitable for simulation of the drought duration and intensity jointed distribution; (2) This area has higher probability of occurrence of drought with both low duration and intensity, short duration and high intensity, and long duration but low intensity. (3) the return period in western Liaoning was relatively short under the combination of high intensity short duration and low intensity long duration, which shows that the western Liaoning was more of light, moderate drought, and return period in most cases was 2～4 months; (4) The actual return period of 1991—2011 was close to that of the theory, which indicates that the joint return period can better reflect the frequency of disaster; (5) The return period of mild drought was less than 2 months, 8 months or more severe drought, 2～8 months to moderate drought. This classification of the drought event can provide a targeted policy for the Agricultural sector to solve the problem of drought disaster. |
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