河南省参考作物蒸散量时空分布特征及主要成因分析

Spatial-temporal distribution characteristics of reference crop evapotranspiration and climate influence factors in Henan Province

根据1951—2016年河南省10个典型气象站点逐日气象资料,利用Penman-Monteith模型计算了参考作物蒸散量,通过Mann-Kendall检验、克里金插值分析、通径分析等方法,对河南省近66 a参考作物蒸散量的时空变化特征及主要影响因素进行了分析.结果表明:河南省整体ET_0随年际变化呈下降趋势,降幅约为1.37 mm/a,其中安阳、洛阳、郑州、商丘、许昌、宝丰、西华和驻马店等地ET_0下降趋势显著;河南省ET_0曾在20世纪80年代初期经历了由高至低的突变,降幅约为62 mm/a;近66 a来,河南省年参考作物蒸散量介于917~1 007 mm之间,中部地区即郑州市南部、许昌市西北部参考作物蒸散量较大,而在东南部即西华、宝丰、商丘和驻马店,参考作物蒸散量较小;突变前后ET_0空间分布差异显著,且四季ET_0空间分布差异明显,其中春季和夏季分布特征与全年分布较为接近;对ET_0构成主要影响的气象因子排序依次为风速、日照时数、平均相对湿度和平均温度;风速、日照时数和平均温度与ET_0呈正相关,平均相对湿度与ET_0呈负相关.该研究可为河南省农田水分管理提供科学依据.

Based on the long-term observational data during 1951-2016 in 10 typical meteorological stations, Henan Province, the daily reference crop evapotranspiration （ET0 ） was calculated with the aid of the revised Penman - Monteith model recommended by FAO. The spatial - temporal distribution characteristics of ETo and its major climate influence factors in 66 years in Henan Province were ana- lysed by perforating the Mann - Kendall test, Kriging spatial interpolation analysis in GIS and path analysis. The results indicate that the overall ET0 shows a yearly declining trend with the decreasing rate of around 1. 37 mm/a, especially a significant decline trend is found in Anyang, Luoyang, Zhengzhou, Shangqiu, Xuchang, Baofeng, Xihua and Zhumadian. Additionally, the ET0 experiences a high -to -low mutation in the early 1980s, when the decrease is as large as approximate 62 mm. In recent 66 years, the annual ET0 was between 917 mm and 1 007 mm. In the central region, the ET0 is smaller. There is a significant difference in spatial distribution of ET0 before and after the mutation. The spatial distribution is distinct in four seasons, especially the distribution characteristics in spring and summer are close to the annual distribution. Effects of meteorological factors on ET0 from the most significant to the least significant are in the following sequence： wind speed, sunshine hours, average relative humidity and average temperature . Further, the wind speed, sunshine hour and average temperature are positively correlated to ET0, while the average relative humidity is negatively correlated to ET0. This study can provide a scientific basis for farmland water management in Henan Province.