open access

https://hdl.handle.net/2115/85974

Application of a coil-type TDR probe for measuring the volumetric water content in weathered granitic bedrock

英語

weathered granite

2008-03-15

Wiley

Hydrological Processes

22(6)

750-763

As a first step toward describing water flow processes in bedrock, a coil-type time domain reflectometry (TDR) probe capableof measuring volumetric water content, in weathered bedrock at three depths was prepared. Because the coil-type TDRprobe is large in diameter (19 mm), it can be installed even in highly weathered bedrock more easily and appropriately thanconventional TDR probes that consists of two or three rods of small diameter (5-8 mm). The probe calibrations suggest thatthe values measured by the probe are very sensitive to changes in. Using the calibrated probe together with commerciallyavailable profile soil moisture sensors, the profile was monitored for 1 year. Even rainfall events with relatively smallcumulative rainfall of 15 mm increased the bedrock, and the increments were comparable to those in the soil. After theend of the rainfall events, the bedrock displayed a more rapid drop than the soil, and varied little during the period of norainfall. The water storage showed similar tendencies. These observations suggest that the bedrock is controlled by clearlydistinguishable macropores and micropores within the bedrock. It is concluded that the coil-type TDR probe is very effectivein determining in weathered bedrock, and that bedrock, conventionally defined by conducting conepenetration tests andtreated as impermeable, does conduct and hold substantial amounts of water, and therefore contribute greatly to hydrologicalprocesses in headwater catchments.

学術雑誌論文

Accepted Manuscript

This is the peer reviewed version of the following article: Katsura, S., Kosugi, K. and Mizuyama, T. (2008), Application of a coil-type TDR probe for measuring the volumetric water content in weathered granitic bedrock. Hydrol. Process., 22: 750-763., which has been published in final form at https://doi.org/10.1002/hyp.6663. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

0885-6087