河南省夏玉米倒伏的天气特征及预报预警

通过对2001—2012年12年间7—9月造成河南省夏玉米发生倒伏的天气形势分析得知，影响河南省夏玉米发生倒伏的天气形势主要有2种，分别是强冷空气型和短时雷雨大风型。强冷空气型根据冷空气路径，可分为强中路偏东型和强西路冷空气型，此种类型造成的夏玉米倒伏范围大，但倒伏程度不一定很强；短时雷雨大风型可分为江淮倒槽型和暖低压前部偏南气流型，此种类型造成的倒伏范围一般较小，局地性较强，但倒伏程度严重，有时甚至发生倒折的情况。从发生倒伏的时间来看，强冷空气造成的倒伏多发生在8—9月，短时雷雨大风发生的倒伏多在7月—8月中上旬，以7月居多。对40个造成夏玉米倒伏个例的天气形势进行统计分析，建立了2种不同形势下发生夏玉米倒伏的天气学模型。强冷空气影响造成的大风一般范围比较大，如果同时伴有强降水出现，夏玉米容易出现大面积的倒伏，对产量造成较大危害，本研究重点分析了2009年8月28—29日一次强冷空气造成夏玉米发生大面积倒伏典型个例的大尺度环流背景场和物理量特征，给出了造成夏玉米倒伏的天气预报预警指标和农事生产建议，以期对降低夏玉米倒伏造成的灾害有所帮助。

The Weather Characteristics and Forecast of Summer Maize Lodging in Henan Province

Based on the observed data from 2001-2012, analysis showed that the weather situations which caused summer maize lodging in Henan Province could be divided into 2 types: strong cold air type and short-term thunderstorms type. According to the path of cold air, strong cold air type could be divided into central-east type and west type, the scope of summer maize lodging caused by strong cold air may be large, but the intensity was not necessarily serious. Short-term thunderstorms type could be divided into Jianghuai invert trough type and the type of south airflow at the front of warm low pressure. Lodging scope of this type was generally small and local, but very serious. Strong cold air usually caused lodging in August and September, while lodging caused by short-term thunderstorms mostly occurred in July and early August, especially in July. Based on the statistical analysis of 40 cases, the author had built synoptic models about summer maize lodging under 2 different types of weather situations. Generally the scope of strong wind caused by strong cold air were relatively large, if accompanied by heavy rain, large area summer maize lodging would likely to occur, cause greater harm to agricultural production. The author mainly analyzed the atmospheric circulation background and the physical characteristics of a typical example at August 28 and 29, 2009, when a strong cold air caused massive lodging of summer maize. The weather forecast warning index and crop production advice were given in order to help reduce the summer maize lodging.