...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Soil Science Society of America Journal >Measuring Near-Surface Soil Thermal Properties with the Heat-Pulse Method: Correction of Ambient Temperature and Soil-Air Interface Effects
【24h】

Measuring Near-Surface Soil Thermal Properties with the Heat-Pulse Method: Correction of Ambient Temperature and Soil-Air Interface Effects

机译：用热脉冲法测量近地表土壤的热学性质：环境温度和土壤-空气界面效应的校正

获取原文
获取原文并翻译 | 示例
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Large temperature gradients and proximity to the soil-air interface affect the measurement accuracy of thermal properties with the heat-pulse probe (HPP). The objective of this study is to improve the HPP methodology for measuring soil heat capacity (C) and thermal conductivity (l) in the surface soil layer by reducing the effects of ambient temperature variation and the soil-air interface. Thermal properties of eight soil layers (0-6, 2-6, 6-12, 12-18, 18-24, 24-30, 30-36, and 36-42 mm) were measured with the HPP in a loamy sand soil in two experiments with varying moisture conditions. Results were compared with values estimated with the de Vries models. Temperature drift caused by natural warming and cooling was removed from the observed trend of ambient temperature change with time. The influence of the soil-air interface was taken into account with a new solution using pulsed infinite line source theory with adiabatic boundary conditions. When ambient temperature change was considered, the HPP were capable of providing reasonable thermal property results at soil depths greater than 6 mm. For the 0- to 6-mm depth layer, the HPP signals were affected simultaneously by ambient temperature drift and the soil-air interface, and mixed scenarios were produced. Around midday, the HPP temperature by time curves were distorted so seriously that the effect of ambient temperature drift could not be removed. At other times, large errors were observed in the estimated C and l data, even when ambient temperature drift was removed. When the effect of the soil-air interface was accounted for, however, C and l measurement accuracies in the 0- to 6-mm layer were improved significantly. The RMSE of C was reduced from 0.43 MJ m(-3) degrees C-1 to 0.29 MJ m(-3) degrees C-1 in Exp. 1, and from 0.52 MJ m(-3) degrees C-1 to 0.34 MJ m(-3) degrees C-1 in Exp. 2. Significant error reduction was also observed in l measurements. Thus, to obtain accurate field measurements of shallow soil thermal properties, the ambient temperature drift and the impact of the soil-air interface must be properly taken into account.
机译：大的温度梯度和接近土壤-空气界面会影响热脉冲探头（HPP）的热性能测量精度。这项研究的目的是通过减少环境温度变化和土壤-空气界面的影响，改进用于测量表层土壤层中土壤热容（C）和热导率（l）的HPP方法。使用HPP在肥沃的沙土中测量了八个土壤层（0-6、2-6、6-12、12-18、18-24、24-30、30-36和36-42毫米）的热学性质在两个湿度条件不同的实验中对土壤将结果与使用de Vries模型估计的值进行比较。从观察到的环境温度随时间变化的趋势中消除了自然变暖和冷却引起的温度漂移。通过使用具有绝热边界条件的脉冲无限线源理论的新解决方案，考虑了土壤-空气界面的影响。考虑环境温度变化时，HPP能够在土壤深度大于6 mm时提供合理的热性能结果。对于0至6毫米深的层，HPP信号同时受到环境温度漂移和土壤-空气界面的影响，并产生了混合情况。在中午左右，HPP温度随时间曲线的失真非常严重，以至于无法消除环境温度漂移的影响。在其他时候，即使消除了环境温度漂移，在估计的C和I数据中也会观察到较大的误差。但是，如果考虑到土壤-空气界面的影响，则0至6 mm层中的C和l测量精度会显着提高。 C的RMSE在Exp中从0.43 MJ m（-3）摄氏度C-1降低到0.29 MJ m（-3）摄氏度C-1。 1和0.52 MJ m（-3）的C-1到Exp。 2.在1次测量中也观察到显着的误差减少。因此，为了获得对土壤浅层热性质的准确现场测量，必须适当考虑环境温度漂移和土壤-空气界面的影响。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号