• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Soil Research >Temporal variability of soil water storage evaluated for a coffee field
【24h】

Temporal variability of soil water storage evaluated for a coffee field

机译：评估咖啡田土壤储水量的时间变异性

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Sampling field soils to estimate soil water content and soil water storage (S) is difficult due to the spatial variability of these variables, which demands a large number of sampling points. Also, the methodology employed in most cases is invasive and destructive, so that sampling in the same positions at different times is impossible. However, neutron moderation, time domain reflectrometry, and, more recently, frequency domain reflectrometry methodologies allow measurements at the same points over long time intervals. This study evaluates a set of neutron probe data, collected at 15 positions placed randomly along a coffee crop contour line, over 2 years at 14-day intervals. The temporal stability of S was again demonstrated, so that wetter or dryer locations remain so over time, and the definition of such positions in the field reduces the number of sampling points in future S evaluations under similar conditions. An analysis was made to determine the minimum number of sampling points to obtain the average S of the field within a chosen level of significance. Classical statistical analysis indicated that the 15 measurement positions could be reduced to four or even to one position to obtain a reliable field S average. State-time analysis showed S estimations depend more on previous measurements of rainfall P (52%) than on evapotranspiration ET (28%) and S (20%). The analysis also showed that ET was not realistically estimated from previous measurements of S; it was more dependent on previous measurements of ET (59%) than on P (30%) and S (9%). This statistical procedure showed great advantages over classical multiple regressions. Future studies of this type should be carried out at regularly spaced observation points in a grid, in order to allow a 2-D and 3-D state-space-time analysis.
机译：由于这些变量的空间变异性，很难对野外土壤进行采样以估计土壤含水量和土壤储水量（S），这需要大量采样点。而且，大多数情况下采用的方法是侵入性和破坏性的，因此不可能在不同时间在相同位置进行采样。然而，中子缓和，时域反射计和最近的频域反射计方法允许在较长时间间隔内在相同点进行测量。这项研究评估了一组中子探针数据，这些数据是在两年内以14天的间隔沿咖啡作物轮廓线随机放置的15个位置收集的。再次证明了S的时间稳定性，因此随着时间的流逝，湿润或干燥的位置保持不变，并且在类似条件下，对田间此类位置的定义减少了未来S评估中的采样点数量。进行分析以确定最小采样点数，以在选定的显着性水平内获得该字段的平均S。经典的统计分析表明，可以将15个测量位置减少到4个甚至一个位置，以获得可靠的场S平均值。状态时间分析显示，对S的估计更多地取决于先前对降雨P（52％）的测量，而不是对蒸散量ET（28％）和S（20％）的依赖。分析还表明，ET并不是根据先前的S值实际估算得出的。它比以前的ET（59％）更依赖于ET（30％）和S（9％）。这种统计程序显示出优于经典多元回归的巨大优势。将来应在网格中规则排列的观察点上进行此类研究，以便进行2-D和3-D状态-时空分析。

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