辽宁省潜在蒸散时空变化特征与成因

潜在蒸散量是衡量变化环境下区域水热资源演变的重要参数,探究其历史变化规律及制约因素对预测农业用水走势乃至合理制定相关决策都至关重要。基于辽宁省23个气象站点1966—2015年的逐日气象数据,采用FAO推荐的Penman-Monteith模型与偏相关性检验法辨识辽宁省近50年潜在蒸散量的时空特征及其影响因素。结果表明:辽宁省各监测站年平均潜在蒸散量为453—1043 mm,多年变化趋势以1.43 mm/a的速度递减,并于2003年发生突变。此外,其时空差异性较为显著。在年代际尺度上表现为,辽西北至辽西南逐次降低;在季节尺度上表现为,夏季潜在蒸散量最高、春秋季节次之、冬季最低;日最高气温、日最低气温和日照时数的减少共同导致过去50年辽宁省潜在蒸散量在整体上表现出减少的趋势。该研究成果可以为水资源的优化配置,评价区域干湿程度等提供一定的理论支撑。

Spatio-temporal distribution characteristics of potential evapotranspiration and impact factors in Liaoning Province

Potential evapotranspiration is an important parameter to measure the evolution of hydrothermal resources in a changing environment. It is essential to explore the history of the potential evapotranspiration rules and constraints to predict the trend of agricultural water and make relevant management decisions. The daily meteorological data from 23 meteorological stations in Liaoning province from 1966 to 2015 were analyzed in this study using the Penman-Monteith model recommended by FAO and the partial correlation test. Spatial and temporal characteristics of potential evapotranspiration and its influencing factors in Liaoning Province in the last 50 years were identified. The results show that the annual average potential evapotranspiration of all monitoring stations in Liaoning Province is 453-1043 mm, with the multiyear trend decreasing at a rate of 1.43 millimeters per year and suddenly increased in 2003. In addition, the temporal and spatial differences of potential evapotranspiration in northwestern Liaoning are significant. It is shown that the potential evapotranspiration gradully decreases from northwest to southwest Liaoning on the interdecadal scale. Additionally, the highest potential evapotranspiration occurs in the summer, followed by spring and autumn, with the lowest occurring in winter, which is on the seasonal scale. The daily maximum temperature, the daily minimum temperature, and the decrease of sunshine hours resulted in the decrease in the potential evapotranspiration in Liaoning in the last 50 years. Together, the research results can provide some theoretical support for the optimal allocation of water resources and evaluation of the degree of regional wetness and dryness.