摘要
参考作物腾发量(ET0)是制定灌溉制度的基本参数,更是干旱评价的必要变量.为全面探究华中华南湿润亚热带地区ET0的时空变化规律及其主要成因,基于该地区1961～2020年246个站点的逐日气象资料和部分大气环流指数,采用Penman-Monteith法计算ET0,结合Mann-Kendall检验、Pettitt、滑动t和累积距平突变检验探究气象要素的变化规律和ET0,并利用Pearson相关分析明确ET0变化的驱动因素.结果表明:Tmean、Tmin、Tmax 呈上升趋势(0.028、0.029、0.019℃/a),n、us、RHmean 波动下降(-0.018 h/a、-0.005 m/(s·a)、-0.052％/a),突变点依次是 1996、1997、1996、1980、1988、1981、1988 和 2002 年.ET0整体呈下降趋势,倾向率为-0.45 mm/a,夏季ET0极显著减少会导致年ET0下降,年、季尺度下ET0的空间分布较复杂.ET0与NAHAI、NANRP、APVA、NAPVA、PPVI、AEPVI 和 AO、AAO、NAO、EM、TSN、SOI 的相关系数分别为-0.86～0.85、-0.07～0.09.ET0的下降趋势在时空上均有体现,与气象要素的变化密切相关,且太平洋区极涡强度指数PPVI是影响ET0变化的最相关因素,结论对该地区制定科学的灌溉制度具有重要意义.
Abstract
Reference crop evapotranspiration(ET0)is a basic parameter for formulating irrigation systems and a necessary variable for drought assessment.In order to comprehensively explore the temporal and spatial variation and the main causing factors of ET0 in the humid subtropical regions of Central and Southern China,we calculated ET0using Penman-Monteith method.The Mann-Kendall test,Pettitt,sliding t and cumulative anomaly mutation method were used to explore the variation of meteorological elements and ET0.The Pearson correlation analysis was applied for the analysis of driving factors of ET0 based on the daily meteorological data of 246 stations in the region,together with atmospheric circulation indices from 1961 to 2020.Results indicated that Tmean,Tmin,and Tmax showed an upward trend(0.028,0.029,0.019 ℃/a),while n,us,and RHmean showed a fluctuating downward trend(-0.018 h/year,-0.005 m/(s·year),and-0.052％/year).The mutation points of meteorological elements in sequence were in 1996,1997,1996,1980 and 1988,1981 and 1988,2002.The overall trend of ET0 decreased with a tendency rate of-0.45 mm/year.A significant decrease in ET0 in summer would lead to a decrease in annual ET0 The spatial distribution of ET0 at the annual and seasonal scales was relatively complex.The correlation coefficients between ET0 and NAHAI,NANRP,APVA,NAPVA,PPVI,AEPVI and AO,AAO,NAO,EM,TSN,SOI were-0.86～0.85 and-0.07～0.09,respectively.The decline trend of ET0 was reflected in time and space,with a close relation to the changes of meteorological elements.The Pacific polar vortex intensity index(PPVI)was regarded as the most relevant factor affecting the change of ET0.The above conclusions are of great significance to provide scientific support of formulating irrigation systems.
基金项目
国家自然科学基金(52209070)
国家级大学生创新创业训练计划(202210712171)
NETL
NSTL
万方数据