不同时间尺度元谋灌区小粒咖啡需水变异特征

Variation research of coffea arabica water requirement at different temporal scale in Yuanmou Irrigation District

为了元谋灌区的水分高效管理,研究了该区不同时间尺度下小粒咖啡需水规律.根据元谋站点1956—2010年逐日气象观测资料,计算并分析不同时间尺度下小粒咖啡需水量和水分盈亏指数的变化特征,采用偏相关分析探讨各气象因子对小粒咖啡需水量的影响程度,利用MannKendall检验法和滑动t检验法分析小粒咖啡年际需水量、水分盈亏指数及气象因子变异规律.结果表明:元谋灌区小粒咖啡年内需水量呈单峰抛物线形状,3—5月为小粒咖啡生长需水关键阶段,对灌溉依赖程度最大;6—10月则是需水量最低时期,水分亏缺最小.近55 a来小粒咖啡需水量呈波动递减趋势,水分盈亏年总值均为负,即水分亏缺,20世纪80年代起需水量开始显著下降,水分亏缺明显减少.风速和日照时数是影响元谋灌区小粒咖啡需水量的最主要气象因子.

The analysis of water requirement regulation for coffea arabica at different temporal scale can provide a basis for optimal water management. Based on the daily meteorological observation data in Yuanmou during 1956—2010,coffea arabica water requirement and crop water surplus deficit index were estimated,and the variation characteristics were analyzed at different temporal scale. The impact of several meteorological factors on water requirement was studied by the partial correlation analysis method. The variation pattern was conducted on the data of the annual water requirement and crop water surplus deficit index by using the Mann- Kendall test and moving t-test. The result showed that the curve of water requirement had a single peak parabolic shape within a year,and the maximum value of water deficit was delete March to May while the minimum from June to October. Coffea arabica water requirement was fluctuant decrease in recent 55 years. Since the 1980 s,water requirement and water deficit began to decrease significantly. The changes of coffea arabica water requirement were primarilyattributed to wind speed and sunshine duration in Yuanmou Irrigation District.