辽宁西部地区玉米生产期降水与干旱分析

Analysis on Precipitation & Drought during Maize Production Period in West Liaoning Area

为了防灾减灾服务,确保粮食生产安全,采用朝阳、阜新、葫芦岛市大气降水1953—2013年资料,运用变化趋势、变率、标准偏差、作物干旱指数等方法分析了辽西地区玉米生产期降水与需水的盈缺关系以及干旱发生频率。结果表明,1953—2013年玉米播种至拔节时段降水表现为弱增加,拔节至成熟时段呈明显减少,开花成熟期近10年降水减少62.0 mm;播种至成熟近10年降水减少64.2 mm。玉米全生育期需水量大于平均降水量,在61年里降水盈余占47.5%,亏缺占52.5%。辽西地区玉米全生育期属于半干旱气候类型,干旱年景占37.7%,其中,播种至出苗期干旱发生频率最高为55.7%,其次是拔节至开花期34.4%,开花至成熟期、出苗至拔节期则最少,分别为16.4%和13.1%。近10年作物干旱指数由半干旱升级为干旱,干旱发生频率增加明显。在农业干旱化日趋严重的状况下,应加快农作物结构调整,并充分利用好地下水资源补充降水不足,减轻干旱所带来的危害。

To serve for disaster prevention and mitigation and ensure grain production safety, the paperadopted atmospheric precipitation data in three cities of Chaoyang, Fuxin and Huludao from 1953 to 2013, andapplied methods of variation trend, variability rate, standard deviation, crop drought index etc., to analyze theample-deficient relation of precipitation and water requirement and drought frequency in West Liaoning areaduring maize production period. The result shows that： from 1953 to 2013, the precipitation has shown anincreasing trend during maize seeding to elongation stage, a trend of significant decrease during elongationstage to mature period. In recent 10 a, the precipitation was reduced 62.0 mm during flowering stage and 64.2mm in all growth period. Water requirement of maize in all growth period was bigger than average rainfall whilein the 61 a, amply rainfall accounted for 47.5% and deficient rainfall accounted for 52.5%. West Liaoning areain maize all growth period belonged to semi-arid climatic zone with 37.7% of the time in a year was semi-arid.Among which, drought frequency during seeding to emergence period was the highest（55.7%）, followed by theelongation to flowering period（34.4%）; and drought frequency was the lowest during flowering to mature periodand emergency to elongation period which was 16.4% and 13.1%, respectively. The recent 10 a crop droughtindex has been upgraded from semi-arid to arid; the drought frequency has obviously increased. Under thesituation of growing agricultural arid tendency, adjustment of crop structure should be speeded up andgroundwater resources should be made full use to complement insufficient rainfall so as to reduce drought damages.