近60年来阿克苏市参考作物蒸散量变化特征及成因分析

Variation Characteristics and Causes of Reference Crop Evapotranspiration in Aksu City in the Past 60 Years

摘要: 为了对近60年来阿克苏市参考作物蒸散量(ET0)的时间变化特征及其成因进行研究，本文采用气候倾向率分析、M-K检验、小波分析以及敏感性和贡献率分析等方法对阿克苏市1955~2018年的气象数据进行研究，并得出以下结论：1) 近60年来阿克苏市ET₀总体呈上升趋势，其中在60年代初至00年代初，ET₀呈明显下降趋势，而在10年代中期呈明显上升趋势，2011年左右ET₀发生了突变；ET₀的变化主周期在50年左右。2) 近60年来，最高温度、最低温度和日照时长呈上升态势，而平均湿度和风速则呈下降趋势。ET₀对于最高温度、风速和平均湿度的敏感程度高，其中最高温度、风速与ET₀的变化趋势相同，平均湿度则与其相反；风速呈较低水平、平均湿度保持较高值是60年代后ET₀下降的可能原因；风速的逐渐上升，平均湿度的快速降低可能是10年代ET₀上升的原因。总体来看，最低温度是近60年来阿克苏市ET₀变化的最主要贡献因子。

Abstract: In order to find the temporal variation characteristics and causes of the reference crop evapo-transpiration (ET₀) in Aksu city in the past 60 years, climate tendency rate analysis, M-K analysis, wavelet analysis, and sensitivity and contribution analysis are used to study the meteorological data of Aksu city from 1955 to 2018, and the result shows that: 1) in the past 60 years, ET₀ in Aksu city generally showed an upward trend, which ET₀ showed a significant downward trend from the early 1960s to the early 2000s, and a significant upward trend in the mid-2010s, with an abrupt change in ET₀ around 2011; the main cycle of ET₀ change was around 50 years. 2) In the past 60 years, the maximum temperature, minimum temperature, and sunshine duration showed an increasing trend, while the average humidity and wind speed showed a decreasing trend. ET₀ was highly sensitive to the maximum temperature, wind speed, and average humidity. The maximum temperature and wind speed had the same trend as ET₀, while the average humidity was the opposite; the lower level of wind speed and the higher value of average humidity was the possible reason for the decrease of ET₀ after the 1960s; the gradual increase of wind speed and the rapid decrease of average humidity may be the reason for the increase of ET₀ in the 2010s. Overall, the minimum temperature was the most important contributor to the ET₀ changes in Aksu city in the last 60 years.