1960-2014 年辽宁中西部地区农业生产期降水与干旱的分布规律

为极端气象灾害预测预报提供依据,采用气候倾向率、湿润指数和积分湿润指数等气候诊断分析方法对辽宁中西部地区的沈阳、阜新及锦州等13个气象站1960-2014年农业生产期(4-9月)的气候资料进行分析,研究该时段内该区域降水变化及干旱发生规律.结果表明:辽宁中西部地区4-9月降水年际变化呈减少趋势,其中中部平原、西南部沿海和西部丘陵区10年气候倾向率分别为-9.81、-10.431 和-10.786,分别线性减少54.0 mm、57.4 mm和59.3 mm.降水减少主要时段出现在7-9月,降水量减少达25.3%.湿润指数减小,气候干旱化明显,中西部平原区1995-2014年气候干旱化程度增加9.9%,西南部沿海区增加11.0%,西部丘陵区增加11.7%.辽宁中西部地区中、重度干旱存在9~11 年的准周期.降水的农业满足度整体下降,线性下降14.3%;1995-2014年降水的农业满足程度平均下降11.5%,造成干旱气候年增加7.3%~9.1%.辽宁中西部地区降水减少导致农业需水满足度下降,干旱频率增加,对大田农业生产已构成威胁.

Distribution Regularity of Precipitation and Drought in Central and Western Regions of Liaoning Province During Agricultural Production Period from 1960 to 2014

The precipitation variation and drought occurrence regularity in Central and Western Regions of Liaoning Province from April to September during 1960-2014 are analyzed by using the data from 13 meteorological stations and the methods of climate tendency rate, humidity index and integral humidity index to provide the basis for prediction and forecast of extreme climate disaster.Results: The interannual variation of precipitation from April to September presents a declining trend.The climate tendency rate of Central Plain Area, Southwestern Coastal Area and Western Hilly Area every ten years is -9.81, -10.431 and -10.786 and 54.0 mm, 57.4 mm and 59.3 mm decreases linearly respectively.Precipitation decrease occurs during July-September mainly and is up to 25.3%, which results in lower humidity index and obvious climate arid.The climate arid degree of Central and Western Plain Area, Southwestern Coastal Area and Western Hilly Area increases by 9.9%, 11.0% and 11.7% during 1995-2014 separately.There is 9~11a quasi-periodicity of heavy drought in Central and Western Plain Area.The agricultural satisfaction degree to precipitation overall declines with 14.3% linear decrease.The agricultural satisfaction degree to precipitation decreases by 11.5% during 1995-2014 averagely, which causes that the arid climatic year increase by 7.3%~9.1%.Therefore, precipitation decrease leads to decrease of agricultural water requirement satisfaction degree and increase of arid frequency, which threatens land agricultural production in Central and Western regions of Liaoning Province.