石羊河流域参考作物蒸散发时空变化及其对气候变化的响应

基于石羊河流域8个气象站点1984—2019年逐日气象资料,分析参考作物蒸散量(ET0)时空变化规律,多种定性与定量分析方法结合,揭示ET0变化与气象因素间的相关关系,确定主导气象要素,探明ET0变化对主导因子敏感程度及贡献.结果表明:石羊河流域ET0上升趋势显著,流域大部分区域达到0.05显著性水平;空间上呈现由南向...

Spatiotemporal variation and response to climate change of reference crop evapotranspiration in Shiyang River Basin

Based on the daily data of eight meteorological stations in Shiyang River Basin from 1984 to 2019, the temporal and spatial variation of ET₀ was analyzed. A number of qualitative and quantitative analysis methods were combined to examine the correlational relationship between ET₀ and meteorological factors, determine the dominant meteorological elements, and explore the sensitivity and contribution of ET₀ changes to the dominant factors. The results showed that the ET₀ had been increased significantly in Shiyang River Basinand reached the significance level of 0.05 in most areas of the basin. In space, it gradually increased from south to north. The high value area(1 148.89~1 246.91 mm) was located in Minqin County, while the low value area(775.30~864.07 mm) was located in Sunan Yugur Autonomous County of Zhangye City and Tianzhu Tibetan Autonomous County of Wuwei City. The order of seasonal variation of ET₀ was summer (409.35 mm)>spring(303.36 mm)>autumn(184.84 mm)>winter(85.6 mm). Except winter, spatial distribution gradually increased from south to north. The results of cluster analysis and grey relational analysis showed that T (average daily temperature), RH (average relative humidity), n (sunshine duration), P (precipitation) and u (wind speed)were the five key meteorological factors. Path analysis results showed that T was the most important factor,and the role of P could be ignored. ET₀ had different sensitivity to meteorological factors. RH was the most sensitive factor affecting the change of ET₀.The first three factors changed in the same direction with ET₀, while RH changed in reverse direction.The contribution rates were 13.61%, 0.48%, 2.34% and 2.86%, respectively.ET₀ in Shiyang River Basin showed an increasing trend, which was due to the joint action of decreasing RH and increasing T, n, and u over the years. The increase of T was the main reason for the increase of ET₀.