考虑多种气候指数的淮河流域气象干旱预测

Prediction of Meteorological Drought in Huai River Basin Considering Multiple Climatic Indices

干旱是一种形成机制复杂的自然灾害,其对人类社会造成的严重危害促使干旱预测技术的发展。为提高淮河流域的干旱预报水平,通过标准化降水蒸散发指数(SPEI)监测干旱状态,利用Regular vine(R-vine)Copula模型建立多维变量联合分布,将厄尔尼诺-南方涛动(ENSO)、中部型ENSO(ENSO Modoki)、北大西洋涛动(NAO)、印度洋偶极子(IOD)和北极涛动(AO)作为预报因子以提高基于SPEI的干旱等级转移的预报精度。分析结果表明R-vine Copula在评价气候指数对转移概率的影响上表现良好,且多维指数较单维指数更能提升预报精度,这与区域气象干旱同时受多种气候因子调节的事实相一致。为多维气候指数影响下干旱转移行为的研究提供了新的认识。

Drought is a natural disaster with complex formation mechanism,and its serious harm to human society promotes the development of drought prediction technology.In this paper,to improve the level of drought forecast in Huaihe River Basin,the standardized precipitation evapotranspiration index(SPEI)is used to monitor the drought condition,and the joint distribution of multi-dimensional variables is established by employing the regular vine(R-vine)Copula model.El Nino-Southern Oscillation(ENSO),Central ENSO(ENSO Modoki),North Atlantic Oscillation(NAO),Indian Ocean Dipole(IOD)and Arctic Oscillation(AO)are taken as predictors to enhance the prediction accuracy of drought level transfer based on SPEI.The results show that the R-vine Copula model performs well in evaluating the impact of climatic indices on drought transfer probability,and that multi-dimensional indices can better improve the prediction accuracy compared with single-dimensional indices,which is consistent with the fact that regional meteorological drought is affected by various climatic factors.This paper provides new insights for research in drought transfer under the influence of multi-dimensional climatic indices.