皖北砂姜黑土地冬小麦生育期尺度干旱指标研究

为给砂姜黑土区小麦干旱灾害监测、预警、评估等工作提供参考,利用代表站点的气象资料、冬小麦生育期观测资料和麦田不同时期土壤水分测定资料,采用平均值、点聚图、有序样本最优聚类等方法,建立了皖北砂姜黑土地冬小麦生育期尺度的土壤水分、降水量负距平百分率、麦田水分盈亏率干旱指标,并分为轻旱、中旱、重旱和特旱4个等级。经检验,降水量负距平百分率指标和水分亏缺率指标的平均正确率均在80%以上,2种指标对重旱和长期干旱具有较强的解释能力。同时,给出了不同生育期发生不同等级干旱时的减产率参考值。

Study on Drought Indices of Winter Wheat During the Growth Stages in the Lime Concretion Black Soil in Northern Anhui Province

In order to provide reference for monitoring,early-warning and assessing drought of winter wheat in lime concretion black soil,the indices of winter wheat in northern Anhui province during the growth stages were set up using meteorological data at the representative sites and statistical method. The drought indices consist of soil moisture,negative anomaly percentage of precipitation and rate of water deficit in wheat field and are classified into four levels (light,medium,severe and extreme). Testing result shows severe and long-term drought were attributed to negative anomaly percentage of precipitation and rate of water deficit with the accuracy over 80%. The reference values of yield reduction rate under different drought levels at different growth stages were also given.