基于主成分回归的草坪蒸散量与其影响因素的研究

本试验历时3年（2015-2017）定位跟踪监测了已建植10多年成熟草坪的蒸散量及其地上生物量、地表枯落物和地下不同层位土壤含水量等11个影响因子，通过主成分回归分析以期探讨影响草坪蒸散量的主要因素，为北方半干旱地区制定精准节水灌溉制度提供理论依据。研究结果表明：经主成分分析，依据其选取原则将所测试的11个影响因子归类得到3个主成分，按其贡献率大小依序为第1主成分（50.64%）、第2主成分（34.40%）和第3主成分（11.56%），三者累积贡献率为96.59%；其次对它们与草坪蒸散量进行回归分析，得出枯落物对草坪蒸散的影响程度最大，且为负相关，地上生物量和0～15 cm深度土层含水量的影响次之，为正相关。

Study on Lawn Evapotranspiration and its Influencing Factors Based on Principal Component Regression

The 3-year experiment (2015-2017) was conducted in a 10-year turf to track and monitor 11 impact factors,such as the evapotranspiration,the ground biomass,litter,and soil water content in different soil layers,etc. Principal component regression analysis was used to explore the main factors affecting the evaporation of turf so that it provided a theoretical basis for the development of accurate water-saving irrigation system in the semi-arid areas of the northern China. The results showed that:the 11 impact factors were classified into 3 principal components based on the principal component analysis. According to their contribution rate,the first principal component was 50.64%,the second principal component was 34.40%,and the third principal component was 11.56%. The cumulative contribution rate was 96.59%. Secondly,the principal component regression between them and the turf grass evapotranspiration showed that the litter had the greatest impact on turf grass transpiration,and was negatively correlated. The impact of biomass and soil water content at 0~15 cm depth was the second and they were positive correlation.