摘要
为研究实际水利条件下农业干旱的发生规律,简化农业干旱事件的评估方法,提出基于区域农业用水量的干旱重现期计算方法。通过构建农业用水量距平百分率干旱指标WA,在基于降雨量距平百分率干旱指标PA识别干旱事件的基础上,提取WA干旱指标下的干旱历时和干旱烈度特征变量,并根据以PA为干旱指标的干旱烈度频率分布曲线FS(x)和干旱历时频率分布曲线FD(x),运用Copula的简化方法计算基于WA的干旱事件重现期T,最后结合基于PA的干旱事件重现期T0,回归分析出T与T0间关系的计算公式。选取干旱灾害影响严重的亳州市为实证区域开展应用研究,计算得到1975—2007年各场干旱事件的T0和T以及T0与T的经验关系式。结果表明:T比T0更合理地反映区域农业实际受旱状况,重现期T0和T间存在高度的相关关系,采用T的回归方程可简化计算考虑区域实际抗旱能力下的干旱事件重现期,在区域防旱减灾实践中具有推广应用价值。
In order to research the appearance of agricultural drought under the actual water projects,the computational method for the return periods of drought events,based on the regional agricultural water consumption,is presented in this study. Through the drought index establishment of the anomalous percentages of agricultural water consumption（ WA）,on the basis of drought events recognized by the drought index PAof precipitation anomalous percentages,the drought characteristic variable of the severity and duration for drought events based on WAwere extracted. Meanwhile,according to the frequency distribution curves FS（x） of drought severity and the frequency distribution curves FD（x） of drought duration obtained with PAas the drought index,the return periods T of drought events based on WA were computed by use of the simplified method of Copula. Finally,combined with the return periods T0 of drought events based on PA,the formula of relationship between T and T0 was obtained through the analysis of regression. The method was applied into Bozhou city as the exemplary region for the severest influence from the drought,and the empirical relation between T and T0 was built as per all the drought events from 1975 to 2007. The results indicate： compared with T0,the severity of drought events judged by T is more consistent with the reality; there is an essential correlation between T0 and T,and the regression equation of T can be accepted as the simple estimation formula of return periods T of drought events when it comes to actual drought resistance ability of one region,and is valuable for popularized application in the process of drought mitigation and loss reduction of one region.
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2017年第5期691-701,共11页
Advances in Water Science
基金
国家自然科学基金资助项目(51579059
51409002)~~
关键词
农业干旱
干旱重现期
频率分析
农业用水量
COPULA函数
抗旱能力
亳州市
agricultural drought
return periods of drought
frequency analysis
agricultural water consumption
Copula function
drought resistance ability
Bozhou city
