黑龙江潜在蒸散发时空变化特征及影响因素

Spatial and Temporal Variation Characteristics and Influencing Factors of Potential Evapotranspiration in Heilongjiang Province

针对当前黑龙江省潜在蒸散发(ET0)长时间序列时空变化特征及影响因子不明的问题,文章利用1960-2018年黑龙江省29个气象站点的逐日气象资料,利用世界粮农组织(FAO)推荐公式计算黑龙江地区逐日潜在蒸散发,并采用Mann-Kendall非参数检验法、Sen斜率方法、皮尔逊相关系数法以及多元回归分析法等方法,得到黑龙江省ET0及其主要气象因子的时空变化特征,并探讨ET0变化的主要控制因子和"蒸发悖论"现象。结果表明:(1)黑龙江省多年平均ET0在727-1286mm之间,平均值为963mm,其中低值区位于黑龙江北部,高值区位于黑龙江西部;(2)ET0年变化速率为在-3.35-1.92mm/a之间,平均值为-0.59mm/a,大部分区域ET0呈下降趋势,大多数站点不存在突变现象;(3)黑龙江绝大部分地区Rn和U2呈下降趋势,VPD呈上升趋势,整个区域T呈显著上升趋势;(4)1960-2018年间黑龙江省总体上存在"蒸发悖论"现象,但在黑龙江北部并不存在"蒸发悖论"现象;(5)在年际变化中,ET0与VPD相关性最高,其次是Rn和U2,而ET0与T之间无明显相关性;贡献率最大的气象因子为VPD和U2。该研究有助于可全面理解气象要素对ET0变化的贡献和响应,为黑龙江省气候变化及农业水资源高效利用等研究提供科学依据。

In view of the current problems about the potential evaporation of Heilongjiang province(ET0)long time series of temporal variation characteristics and impact factors,according to the daily meteorological data of 29 meteorological stations from 1960 to 2018 in Heilongjiang Province,the World Food and Agriculture Organization(FAO)recommended formula was used to calculate the daily ET0.Using Mann-Kendall nonparametric test,Sen slope method,Pearson correlation coefficient method and multiple linear regression analysis method,the temporal and spatial variation characteristics of ET0 and its main meteorological factors in Heilongjiang Province were obtained,and the main control factors of ET0 and evaporation paradox were discussed.The results are as follows:①The annual average ET0 in Heilongjiang Province is between 727 and 1286mm,with an average value of 963mm.The low value area is located in the north of Heilongjiang Province,while the high value area is located in the west of Heilongjiang Province.②The annual change rate of ET0 is between-3.35 and 1.92mm/a,with an average value of-0.59mm/a.In most regions,ET0 shows a downward trend,and no mutation is found in most stations.③In most areas of Heilongjiang Province,net radiation(Rn)and wind speed(U2)show a downward trend,water vapor pressure difference(VPD)shows an upward trend,and the whole region T shows a significant upward trend.④From 1960 to 2018,the evaporation paradox exists in Heilongjiang province in general,but it does not exist in the north of Heilongjiang.⑤In the interannual variation,the correlation between ET0 and VPD is the highest,followed by Rn and U2,while there is no obvious correlation between ET0 and T.The meteorological factors with the largest contribution are VPD and U2.This study helps to fully understand the contribution and response of meteorological elements to ET0 changes,and provides a scientific basis for the research on climate change and effective utilization of water resource in Heilongjiang Province.