东北农业区降水年内分配的不均匀性及对区域增暖的响应

Inhomogeneous distribution of precipitation in Northeast China agricultural zone and its response to regional warming

水热的合理配置为农业生产提供了有利的气候条件,明确热量和水分的匹配及变异规律对指导农业生产具有重要意义。本文利用东北农业区1961—2014年的逐日降水和气温资料,分析了东北农业区降水年内分配不均匀性的变异规律及其对区域增暖的响应,结果表明:(1)近54年来,该区表现为全区一致性的降水年内分配不均匀性降低、年际变化幅度增大和降水集中期提前的变化趋势;(2)降水年内分配不均匀性降低速率表现为中间大,南、北小的区域间差异;(3)降水年内分配不均匀性对气温具有很强的响应,表现出明显的不同步和区域间差异性,大致表现为在短周期上降水集中度落后气温、而长周期上超前气温的响应特征。气候增暖背景下,降水集中期的提前使得该区雨热同期的气候要素匹配关系保持稳定,但降水年内分配不均匀性的降低及年际间变化幅度的增大可能会增加该区夏季发生干旱的风险。研究结果可为制定科学的农田水管理策略提供参考。

The rational allocation of heat and water provides favorable climatic conditions for agricultural production.It is important to make clear the matching and variation rule of heat and water for guiding agricultural production.Based on the data of daily precipitation and temperature from 1961 to 2014 in Northeast China agricultural zone(NCAZ),the variation law of inner-annual inhomogeneous distribution of precipitation(IIDP)and its response to regional warming in NCAZ were analyzed.The results show that:(1)In 1961-2014,the trends was found and characterized by decreasing IIDP,increasing inter-annual variation of IIDP and being more early precipitation concentration period(PCP)consistently in the whole NCAZ;(2)The decrease rate of IIDP was larger in the middle of NCAZ,contrast to smaller value in southern and northern part of NCAZ;(3)The IIDP depended on air temperature strongly,which showed obvious asynchronism and inter-regional difference with precipitation concentration degree(PCD)being behind air temperature on short period and beyond on long period mainly.In a more warming world,the advance of PCP keeps simultaneous heat and precipitation stable,but the decrease of IIDP and the increase of the inter-annual variation may increase the risk of summer drought in NCAZ.The results can provide a reference for formulating scientific farmland water management strategies.