安徽省一季稻播栽关键期极端气候指数分布特征及其影响

The distribution characteristics and influence of extreme climate indices in key stage of single-season rice planting in Anhui Province

利用1970—2014年安徽省的逐日气象数据和一季稻播栽面积数据,计算出育秧腾茬期和移栽期的19个极端气候指数(ECI),分区讨论ECI与一季稻种植面积波动的相关性,最后分析关键指数的时间变化特征。结果显示:降水和气温分别呈“北少南多”和“南北高中间低”的分布特征,划分为5个研究亚区。播栽面积波动主要与育秧腾茬期的极端气候有关,大部分区域与育秧腾茬期夏季日数(SU)、连续无雨日数(CDD)呈正相关,与降水日数(DR)呈负相关。关键ECI的变化趋势总体呈有利于一季稻播栽的方向发展,其中育秧腾茬期的SU和CDD整体呈显著上升趋势,DR呈显著下降趋势,未来变化趋势均有可持续性;DR的距平变化呈“升-降-升-降-升”的波动特征,在1970s后期和1990s中期发生突变,整个研究时段存在2~4年的周期振荡。揭示了育秧期低温阴雨、移栽期区域性少雨是导致安徽一季稻种植面积负波动的首要气候因素。

Based on the daily meteorological data and single-season rice planting area data in Anhui Province from 1970 to 2014,19 extreme climate indices(ECI) were calculated for the seedling-harvesting stage and transplanting stage.The correlation between ECI and the fluctuation of single-season rice planting area was discussed,and the temporal variation characteristics of key indices were analyzed.The results showed that the distribution of precipitation and temperature was’less in the north and more in the south’,and the temperature was characterized by’high in the north and low in the middle’,respectively,which could be divided into five sub-regions.The fluctuation of planting area was mainly related to the extreme climate in the seedling-harvesting stage,and most of the area was positively correlated with summer days(SU) and continuous days without rain(CDD),and negatively correlated with precipitation days(DR) in most regions.The change trend of key ECI was generally in favor of single-season rice planting,in which SU and CDD showed a significant increase trend and DR showed a significant decrease trend in the whole seedling stubble stage,and the future trends were sustainable.The anomaly of DR showed a fluctuation characteristic of’up-down-up-down-up’,and abrupt change in the late 1970s and mid-1990s,and a 2-4 year periodic oscillations throughout the whole study period.It was revealed that low temperature and rainy day during the stage of single-season rice seedling and regional drought during the stage of ransplanting were the main climatic factors leading to the negative fluctuation of single-season rice planting area in Anhui province.