近60年雷州半岛气象干旱变化特征及驱动因素分析

Analysis of Variation Characteristics and Driving Factors of Meteorological Drought in Leizhou Peninsula in Recent 60 Years

雷州半岛为中国华南农产品重要的主产区,区内水系大多独流入海,加上工程调蓄能力不足,干旱已成为制约当地经济发展的主要因素。通过计算不同尺度下的标准化降水蒸散指数(Standardized Precipitation-Evapotranspiration Index,SPEI)来分析雷州半岛气象干旱的变化特征,探究降水、气温和遥相关因素对雷州半岛干旱的影响。结果表明:①年尺度上雷州半岛干旱事件发生频率接近20%,北部呈现出显著湿润化的趋势,南部湿润化的趋势不显著,北部较易发生极端干旱事件;②降水与气温均与SPEI呈显著性相关关系,且降水与干旱的相关性更强;③海洋尼诺指数(Ocean Nino Index,ONI)与次年SPEI的负相关性显著,说明ENSO(EI NiÑo-Southern Oscillation)事件与干旱的关系密切,且当发生东部型和中部型ENSO暖事件时,对干旱的影响存在差异。研究成果可为即将实施的雷州半岛灌区工程提供参考。

Leizhou Peninsula,a main crop producing area in South China,is majorly restricted by drought in terms of economic development because most of the rivers in this region are unbranched and the capacity of engineering regulation and storage is insufficient.In this paper,the standardized precipitation and evapotranspiration index(SPEI)at different time scales was calculated to analyze the variation characteristics of meteorological drought in the Leizhou Peninsula and to explore the influence of precipitation,temperature and teleconnection factors on the drought in the Leizhou Peninsula.The results show that:①The frequency of annual drought in the Leizhou Peninsula is close to 20%,and the northern part shows a significant trend of wetting,while the southern part shows no significant trend of wetting.The northern part is more extreme drought-prone.②Precipitation and temperature are significantly correlated with SPEI,with a stronger correlation between precipitation and drought.③There is a significant negative correlation between the ocean Nino index(ONI)and the SPEI of the following year,indicating that ENSO is closely related to drought,and there is a difference in the impact on drought when the eastern and central ENSO warm events occur.The research results can provide references for the Leizhou Peninsula Irrigation District project to be implemented soon.