近40年来四川盆地参考作物蒸散量时空特征分析

Impact of Climate Change on Evapotranspiration of Reference Crops in the Sichuan Basin

摘要: 准确估算参考作物蒸散量对于灌溉预报、水资源调度和规划有着重要意义。本文基于1978~2016年四川盆地8个资料完整且具有代表性气象站点的观测数据，利用Penman-Monteith公式计算参考作物蒸散量，分析了参考作物蒸散量的时空变化特征，并初步分析了其与气象要素的关系，结果表明：1) 四川盆地年参考作物蒸散量近40年来整体上呈显著增加趋势，空间分布上表现为盆地中部区域最小，北部区域最大，最大值达到了1149 mm；2) Mann-Kendall突变检测表明年参考作物蒸散量在2000年发生了显著的突变型增大，Morlet小波分析显示参考作物蒸散量存在10~16年和50~60年时间尺度周期，其中50~60年时间尺度的周期较为显著。3) 参考作物蒸散量与气温、日照时数和风速呈极显著正相关，与相对湿度呈极显著负相关关系。

Abstract: Accurate estimation of reference crop evapotranspiration is of great significance for irrigation forecasting, water resources scheduling and planning. Based on the observation data from eight mete-orological stations with complete and representative data in the Sichuan basin from 1978 to 2016, the spatial and temporal variation characteristics of reference crop evapotranspiration calculated by the Penman-Monteith model is analyzed. The results show that: 1) the annual average reference crop evapotranspiration has shown an overall significant increasing trend in the past 40 years. In terms of spatial distribution, the reference crop evapotranspiration is the smallest in the middle area of the basin and is the largest in the north area with the maximum value 1149 mm. 2) Mann-Kendall mutation detection shows that the annual reference crop evapotranspiration has increased significantly in 2000, and Morlet wavelet analysis shows that the reference crop evapo-transpiration has two time scale cycles which are from 10 to 16 years and from 50 to 60 years, among which the latter cycle is more significant. 3) The reference crop evapotranspiration is highly significantly positively correlated with temperature, sunshine hours and wind speed, while is highly negatively correlated with relative humidity.