1965-2007年沙澧河流域潜在蒸散量变化趋势

利用1965-2007年沙澧河流域12个气象站的逐月气候资料,采用FAO推荐的彭曼-孟蒂斯公式计算潜在蒸散量,分析了沙澧河流域43 a潜在蒸散量的变化趋势,并在ArcGIS环境下通过Spline插值法分析了该流域潜在蒸散量空间分布特征,此外还对造成潜在蒸散量变化的主要气候影响因子进行了探讨。结果表明:从空间分布来看,潜在蒸散量年和四季从西北到东南基本呈下降趋势。从时间变化来看,年潜在蒸散量略呈下降趋势,但变化不明显;冬、春季呈增加趋势,年际变化率分别为0.189 mm.a-1和0.540 mm.a-1,夏、秋季呈减小趋势,其中夏季减少尤其明显,年际变化率为-1.354 mm.a-1。日照是影响年和夏、秋季潜在蒸散量变化的主导因素,而气温是影响冬、春季潜在蒸散量变化的主导因素。

Potential Evapotranspiration Trends of Sha Li River Basin From 1965 to 2007

Based on the monthly climate data of 12 weather stations in Sha Li River Basin form 1965 to 2007, using Penman-Monteith formula recommended by FAO to calculate potential evapotranspiration, the 43 a potential evapotranspiration trend in Sha Li River basin were analyzed, the spatial distribution characteristics of potential evapotranspiration in this basin were analyzed by Spline interpolation method in ArcGIS environment, and the major climate influence factors change potential evapotranspiration were discussed also. The results show that: From the spatial distribution, the annual and quarterly potential evapotranspiration from northwest to the southeast of basic have downward trend; from temporal variations, the annual potential evapotranspiration has slightly downward trend, but does not change significantly; Winter and spring have an increasing trend, the annual interannual variation rates were 0.189mm / a, and 0.54mm / a, summer and autumn are reduced trend, which is particularly evident in summer, with inter-annual change rate of -1.354mm / a; sunshine is a dominant factor affect the change of annual, summer and autumn potential evapotranspiration, and the temperature is the dominant factor affect the change of winter and spring potential evapotranspiration.