Despite the potentially negative effects on play performance and safety, little is currently known about the spatial and temporal variability in the properties of artificial turf pitches. The primary purpose of this study was to quantify the spatial and temporal variations in surface hardness across a 5-year-old third-generation artificial turf pitch over full year cycle. The secondary purpose was to investigate the key variables that contributed to these variations in surface hardness using a correlation approach. Surface hardness (2.25 kg Clegg impact hammer, average of drops 2–5), ground temperature and infill depth were measured at 91 locations across the third-generation artificial turf pitch in 13-monthly test sessions from August 2011 to August 2012 inclusive. For each month, rainfall in the 24 h prior to testing and pitch usage statistics were also obtained. Shockpad thickness was obtained from measurements taken when the carpet was replaced in 2007. Spatial and temporal variations were assessed using robust statistical measures while Spearman correlation was used to assess the contributions of the secondary variables to surface hardness variability. The results indicated that spatial variation in surface hardness exceeded temporal variation; the former demonstrated a median absolute deviation of 12 ± 1 G across the pitch in any test session while the median absolute deviation for the latter was only 4 ± 2 G across the 13 test sessions. Spatial variation in surface hardness was moderately correlated with shockpad thickness and weakly correlated with infill depth (both negative). These results reinforce the importance of monitoring spatial and temporal variations in play performance variables for third-generation surfaces as well as providing support for the role of maintenance in minimising the spatial variation.

中文翻译：

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一年多来第三代人造草坪球场表面硬度的时空分析

尽管对比赛表现和安全有潜在的负面影响，但目前对人造草坪球场特性的空间和时间变化知之甚少。本研究的主要目的是量化 5 年历史的第三代人造草坪球场在全年周期内表面硬度的空间和时间变化。第二个目的是使用相关方法研究导致表面硬度变化的关键变量。在 2011 年 8 月至 2012 年 8 月（含）的 13 个月测试期间，在第三代人造草坪球场的 91 个位置测量了表面硬度（2.25 千克克莱格冲击锤，平均跌落 2-5 次）、地面温度和填充深度。每个月，还获得了测试前 24 小时的降雨量和沥青使用统计数据。Shockpad 厚度是通过 2007 年更换地毯时进行的测量获得的。空间和时间变化使用稳健的统计措施进行评估，而 Spearman 相关性用于评估次要变量对表面硬度变化的贡献。结果表明，表面硬度的空间变化大于时间变化；前者在任何测试环节中都显示出 12 ± 1 G 的中值绝对偏差，而后者在 13 个测试环节中的中值绝对偏差仅为 4 ± 2 G。表面硬度的空间变化与减震垫厚度适度相关，与填充深度弱相关（均为负值）。