阿克苏河灌区作物理论需水量的时空分布特征

目的]研究阿克苏河灌区作物的理论需水量的时空变化特征,为该区水资源科学管理、高效利用提供理论依据。方法]基于灌区内1972—2014年6个气象台站的逐日气象观测数据,采用FAO修正的Penman-Monteith模型,计算参考作物蒸发蒸腾量(ET0),进行空间数据的插值分析,对阿克苏河灌区作物的理论需水量特征分别在空间和时间两个维度上进行探讨。结果](1)阿克苏河灌区多年平均ET0介于1 118~1 241mm之间,呈现中部以北地区较低,西南部、南部地区较高的规律;(2)春季和夏季的ET0最高,5,6,7月的月均ET0合计为533mm,是作物最需要水分补给的重要时段;(3)自20世纪70年代至今,作物年均蒸发蒸腾量呈现逐渐降低的趋势,2010年以后的变化趋势较为显著;(4)灌区各季节及全年的ET0变化均呈现S形曲线分布,至2014年已接近波谷并有抬升趋势。结论]在气候变化背景下,阿克苏河灌区作物的理论需水量随时间变化显著,春夏季受蒸腾作用影响是需要补水的关键时期,年际变化呈波动抬升趋势;在空间上亦呈现明显地带分异特点,呈南高北低的特征。

Temporal and Spatial Distribution of Theoretic Water Requirement of Crop in Aksu River Irrigation Area

Objective] This study aimed to explore the temporal and spatial distribution of theoretic water requirement of crop in Aksu River irrigation area. It would be the theory evidence for water resources management and high efficient utilization.Methods] Based on the daily weather observation data of 6 meteorological stations during 1972-2014, the research was carried out using the correction model of Penman-Monteith which was recommended by FAO. The reference crop evapotranspiration(ET₀) were calculated, and the spatial data interpolation was executed. The theoretic water requirement of crop in Aksu River Irrigation Area was discussed based on the dimension of temporal and spatial.Results] (1) Annual mean ET₀ was between 1 118 and 1 241 mm. It showed a trend of gradually increasing from the northern area to the southern area. (2) The value of ET₀ was the highest in spring and summer. The total value of ET₀ was 533 mm in the months of May, June and July, a period having the most need for water supplement. (3) Yearly reference crop evapotranspiration showed a trend of gradually decrease since 1970 s, and a significant decreasing trend after 2010 s. (4) The ET₀ variation presented a S-type curve, after the year of 2014, it showed an increasing trend.Conclusion] The theoretic water requirement of crop showed a significant change over time in Aksu River Irrigation Area in the context of climate change. Spring and summer were the critical periods of irrigation. It showed a fluctuated and inclined steadily trend. Zone differentiation characteristics were obvious.