Development of a tool to monitor distribution of soil hydrological properties in situ.

开发现场监测土壤水文特性分布的工具。

基本信息

批准号：
13556036
负责人：
NISHIMURA Taku
金额：
$ 7.62万
依托单位：
National University Corporation Tokyo University of Agriculture and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2004
项目状态：
已结题

项目摘要

Apply dielectric constant method to measure volumetric water content of soils to assess dry bulk density of the soil. Volumetric water content couple with either mass wetness or wet bulk density can produce dry bulk density. Trials with time domain reflectometry(TDR) probe and Amplitude domain reflectometry(ADR) probe gave good results. Estimated dry bulk density agreed well with the measured dry bulk density of disturbed soils. For non disturbed soils, accuracy was worse than that of the disturbed soil however accuracy was good enough for practical purpose. Relatively, dry bulk density estimated by using volumetric water content and wet bulk density was better than that by using the combination of volumetric water content and mass wetness. This was due to arithmetic process of data calculation. Most significant source of estimation error was heterogeneity of water content distribution along with sensing rod of water content sensors. Laboratory experiment showed that especially for ADR probe, uneven distribution of water content collapsed reliability of measurement of volumetric water content.Scaling of saturated hydraulic conductivity by using dry bulk density was conducted. Estimated saturated hydraulic conductivity distribution had similar spatial structure with measured ones. This was evaluated by using semrvariogram.Performance of tension infiltrometer as in-situ measurement device of soil hydraulic property was examined. There were several improvements in tension infiltrometer and this improved easiness and time for measurement. Result of tension infiltrometer well explained leaching phenomena in upland field than common methods such as saturated hydraulic conductivity and cylinder intake rate.

应用介电恒定方法来测量土壤的体积水分含量，以评估土壤的干块密度。体积的水含量夫妇具有质量湿度或湿块密度可以产生干燥的散装密度。具有时域反射测量法（TDR）探针和振幅域反射学（ADR）探针的试验得出了良好的结果。估计的干燥大体密度与受干扰土壤的干燥大体密度很好地达成了一致。对于无干扰的土壤，准确性比被干扰的土壤要差，但是准确性足以实用。相对而言，通过使用体积水含量和湿块密度估算的干燥大体密度要比使用体积水含量和质量湿度的组合更好。这是由于数据计算的算术过程。估计误差的最重要来源是水含量分布的异质性以及水含量传感器的传感棒。实验室实验表明，尤其是对于ADR探针，水含量的不均匀分布崩溃了体积水含量的测量可靠性。通过使用干散装密度进行饱和液压电导率的尺寸。估计的饱和水力电导率分布具有相似的空间结构，测得的结构相似。通过使用Semrvariogram来评估这一点。张力渗透计作为土壤液压特性的原位测量装置。张力渗透计有几种改善，这种敏捷性和测量时间有所改善。张力渗透计的结果很好地解释了高地场中的浸出现象，而不是饱和的液压传导率和气缸摄入速率。