基于5变量局部薄盘光滑样条函数的蒸发空间插值

Modeling spatial distribution of pan evaporation based on quinat-variate thin plate spline function

高分辨率、栅格化的气候数据作为环境因子是地学模型和气候模型等相关研究的重要参数,国内外的研究多集中于温度、降水等气象要素,对陆面蒸发空间化研究较少。对黄土高原多沙粗沙区及周围共计53个气象站点(多沙粗沙区30个)蒸发皿测量值Epan进行空间插值,以5变量局部薄盘样条函数(经纬度为自变量,净辐射、水气压差和风速为协变量),建立具有多元线性子模型的蒸发插值模型,以ANUSPLIN为实现软件,生成连续21年共252个蒸发表面。交叉验证表明:引入蒸发影响因子作为协变量线性子模型进行表面插值能显著提高插值精度,夏季提高幅度更大,拟合表面具有较高的精确度与平滑度。蒸发随协变量的变率显示,在多沙粗沙区,水气压差是夏季蒸发的主要控制因素,风速对蒸发的影响冬季稍强一些,净辐射的影响没有明显的季节性,只在春分和秋分时节有微小提高。

Spatial distribution of pan evaporation （Epan） depending on multiple factors such as radiation, vapor pressure and wind is a crucial parameter for geographic models and climatic models, and also a key to environmental management. However the weather observation stations normally distribute sparsely and irregularly on the ground. The techniques to interpolate available point data to estimate the value of any location is demanded. This paper introduces the process to interpolate monthly Epan data of 53 stations for the period of 1980 to 2000 to create 252 Epan surfaces in Coarse Sandy Hilly Catchments of Loess Plateau. Quinat-variate partial thin plate spline models were developed wind speed（wind） were used as three covariate tion surfaces hold high fidelity and smoothness. in which vapor pressure deficit sub-models. GCV statistics indi （Pd cate ）, net radiation （R,） and that the resultant evapora- The lapse rates （evaporation changing rate with each covariate） showed that ： the dependence of Epan on Rn has no strong seasonal trend although at the equinoxes it is slightly big, whereas the dependence of Ep.. on pa has an obvious trend with strongest influence in summer, and wind speed has more relative influence in winter.