辽宁省潜在蒸散发量及其敏感性规律分析

Analysis of Potential Evaporation and Its Sensitivity in Liaoning Province

采用Penman-Monteith法和敏感系数法对辽宁省1965~2014年潜在蒸散发量及影响潜在蒸散发的气象因子敏感性进行分析,探讨气候变化下影响辽宁省潜在蒸散发量变化的主导因子及潜在蒸散发对气候变化的定量响应。结果表明:(1)近50 a辽宁省潜在蒸散发呈现显著减少趋势,在空间上由西向东递减;(2)潜在蒸散发对气象因子的敏感性在年尺度上表现为,水汽压最为敏感,其次为太阳辐射、风速、平均气温;在季节尺度上,春季和秋季对平均气温最不敏感,夏季对风速最不敏感,冬季对太阳辐射最不敏感;(3)空间分布上,气象因素的敏感系数与气象因子空间变化规律相吻合,潜在蒸散发对气温的敏感性由北部向南部递增,对水汽压、太阳辐射的敏感性由东部向西部递减,而风速与之变化趋势相反。(4)风速的显著降低是辽宁省潜在蒸散发量下降的主要原因,太阳辐射的下降及水汽压的升高也促使了潜在蒸散发量的下降。

Research the change of potential evapotranspiration and its sensitivity, it is of great significance for agricultural sustainable development and protection of the ecological environment. This article use Pen- man-Monteith method and sensitivity coefficient method to analyze spatial and temporal variation of potential evapotranspiration and sensitivity of potential evapotranspiration to average temperature, wind speed, solar ra- diation, and vapor pressure from 1965 to 2014 in Liaoning Province. It aimed to investigate the dominant fac- tors affecting the potential evapotranspiration and the quantitative response of potential evapotranspiration to climate change. The results showed that： Nearly 50 years potential evapotranspiration showed a significant de- crease trend. In space, it presented by the west to east decreasing trend. The reference evapotranspiration was most sensitive to vapor pressure, which is followed by solar radiation and wind speed, average temperature on an annual scale. In terms of season, average temperature was the least sensitive variable in spring and autumn, wind speed was the least sensitive variable in summer and solar radiation was the least sensitive variable in winter. Spatially speaking, spatial variation of meteorological factors and its sensitivity coefficient are consis- tent during the year. Sensitivity to the temperature of the potential evaporation is increasing north to the south, sensitivity to the vapor pressure and solar radiation of the potential evaporation is decreasing east to west, but the change of wind speed is opposite. The main reasons for the decrease of potential evapotranspiration in Lia- oning Province are the significant decrease of wind speed, and the decrease of solar radiation and the increase of vapor pressure also contribution to the decrease of potential evapotranspiration.