首页   按字顺浏览 期刊浏览 卷期浏览 MEASURING WATER EXCHANGE BETWEEN SOIL AND ATMOSPHERE WITH TDR‐MICROLYSIMETRY
MEASURING WATER EXCHANGE BETWEEN SOIL AND ATMOSPHERE WITH TDR‐MICROLYSIMETRY

 

作者: JOHN BAKER,   GBERT SPAANS,  

 

期刊: Soil Science  (OVID Available online 1994)
卷期: Volume 158, issue 1  

页码: 22-30

 

ISSN:0038-075X

 

年代: 1994

 

出版商: OVID

 

数据来源: OVID

 

摘要:

Soil evaporation is an important hydrologic and energy transfer process, yet it has historically been difficult to measure. Weighing microlysimetry is a commonly employed and accepted technique that is accurate and inexpensive, but, it is time consuming and labor intensive, with lim-ited temporal resolution. We modified the method by fitting a time domain reflectometry (TDR) probe in each microlysimeter extending from the bottom to the top. When they are installed, the probes pierce a plastic film lining the bottom of the microlysimeter. The holes thus created allow free drainage when rainfall is sufficient to induce it, but they prevent unsaturated flow either direction. The use of an automated TDR system allowed continuous, unattended measurement of both evaporative losses and rainfall additions in multiple lysimeters. The TDR data compared favorably with water content changes measured at discrete intervals by weighing, and also with independent measurements of daily evaporation losses' and rain-fall additions measured by the Bowen ratio method and a rain gauge. Short-term (e.g., hourly) rate estimation exhibited considerable scatter, but further improvement should be possible. The TDR-microlysimeters were replaced less frequently than typically the case with standard microlysimeters, without serious consequences despite numerous rains. The method should be useful in many studies where information on soil/atmosphere water exchange is required.

 

点击下载:  PDF (696KB)



返 回