湖北汉江流域潜在蒸散量时空变化特征分析

Analysis of Temporal and Spatial Variation Characteristics of the Potential Evapotranspiration of Hanjiang River Basin in Hubei

为了在全球气候变暖的背景下,探索湖北汉江流域蒸散发的变化趋势,为农业生产布局及水资源有效利用提供依据。以湖北汉江流域13个气象站点1960—2011年的逐日气象资料为基础,采用FAO推荐的Penman-Monteith模型计算潜在蒸散量,用Mann-Kendall非参数检验法对其进行趋势分析和突变检验,并在Arc GIS环境下利用克里金插值分析潜在蒸散量的空间变化特征。结果显示:湖北汉江流域1960—2011年的潜在蒸散量整体呈波动下降趋势,变化速率为-16.792 mm/10 a,均值为792 mm;夏季整体下降趋势明显,变化速率为-15.149 mm/10 a,春季整体呈上升趋势,变化速率为4.171 mm/10 a,秋季和冬季变化趋势不明显;潜在蒸散量空间分布特征表现为自东南向西北递减,较高的地区主要集中在武汉、广水、天门一带;1968年前后,潜在蒸散量出现1次突变。

The paper aims to explore the tendency of potential evapotranspiration of Hanjiang River Basin in Hubei under the global warming, so as to provide the reference for the layout of agricultural production and the effective use of water resources. Based on the daily meteorological data from 1960-2011 provided by 13 meteorological stations of Hanjiang River Basin in Hubei, the Penman-Monteith model recommended by FAO was used for calculation of potential evapotranspiration. The Mann-Kendall nonparametric test was used for analysis of tendency and test of abrupt change. And based on ArcGIS, the kriging interpolation was used to analyze the spatial variation characteristics of potential evapotranspiration. The results showed an overall wavelike decrease of potential evapotranspiration of Hanjiang River Basin in Hubei from 1960 to 2011 with the changing rate of- 16.792 ram/10 a and with the mean of 792 mm. In summer, the change presented a significant overall declining with the changing rate of- 15.149 mrrdl0a. In spring, the change had an overall increase with the changing rate of 4.171 mm/10a. No apparent change could be found in autumn and winter. The spatial distribution characteristics for potential evapotranspiration manifested a gradual decrease from southeast to northwest. Higher potential evapotranspiration mainly showed around three cities-Wuhan, Guangshui and Tianmen. And the potential evapotranspiration showed an abrupt change around 1968.