Soil Water

Soil water measurements are being collected throughout the Reynolds Creek Experimental Watershed using a variety of methods. Measurement by neutron probe have been taken bi-weekkly since the early 1970's. The length of record and number of readings taken varies for different sites. The main data collection effort was initiated between 1970 and 1973 using 48 mm diameter aluminum access tubes installed to varying depths. The holes were excavated using a “Houston” rotary core drill using air pressure. This was essential for most sites because of the high rock contents common in RCEW soils. It was generally felt by early investigators that the sample volume probably changed slightly shortly after tube installation as the soil settled around the tubes.

Measurements at all tubes were made at a depths of 0.15 and 0.305 m followed by readings at 0.305 m intervals to the bottom of the tube, which ranged from 0.61 to 2.74 m. Except where noted, 30 second counting times were used. Readings were made at approximately biweekly intervals with ~20 readings per year. The data record for 1996 for all tubes is very sparse because of a combination of equipment failure and personnel changes. A tube was installed in each of the four RCEW lysimeters. The two tubes in the Reynolds Mountain lysimeters were not monitored when there was significant snow cover because they were intended to track growing season soil water use. Five different neutron probes were used over a 26 year period. From 1970 to 1979, two probes manufactured by Troxler were used (492 and 152); these were replaced with two probes manufactured by Campbell Nuclear Pacific (606 and 607).

Long-term soil water database, Reynolds Creek Experimental Watershed. Idaho, United States.

SiteNameMaximum
Depth (m)
StartStopYears of
Record1)
057896 Flats Neutron Probe Soil Moisture Tube 057896 1.22 1976 2014 39
057c96 Flats Neutron Probe Soil Moisture Tube 057C96 1.22 1976 2014 39
057h96 Flats Neutron Probe Soil Moisture Tube 057H96 0.91 1986 2014 29
076059 Quonset Neutron Probe Soil Moisture Tube 076059 1.22 1981 2014 34
076159 Quonset Neutron Probe Soil Moisture Tube 076159 0.91 1987 2014 28
098697 Nancy Gulch Neutron Probe Soil Moisture Tube 098697 1.22 1976 2014 39
098897 Nancy Gulch Neutron Probe Soil Moisture Tube 098897 1.22 1976 2014 39
098f97 Nancy Gulch Neutron Probe Soil Moisture Tube 098F97 0.61 1976 2014 39
117079 Lower Sheep Creek Neutron Probe Soil Moisture Tube 117079 0.91 1976 2014 39
117186 Lower Sheep Creek Neutron Probe Soil Moisture Tube 117186 2.74 1976 2014 39
127707 Lower Sheep Creek Neutron Probe Soil Moisture Tube 127007 0.91 1976 2014 39
127807 Lower Sheep Creek Neutron Probe Soil Moisture Tube 127807 0.91 1976 2014 39
127907 Lower Sheep Creek Neutron Probe Soil Moisture Tube 127907 1.82 1976 2014 39
176006 Reynolds Mountain Neutron Probe Soil Moisture Tube 176006 1.22 1976 2014 39
176025 Reynolds Mountain Neutron Probe Soil Moisture Tube 176025 0.91 1977 2014 38
176125 Reynolds Mountain Neutron Probe Soil Moisture Tube 176125 0.91 1977 1995 19
176225 Reynolds Mountain Neutron Probe Soil Moisture Tube 176225 0.91 1977 1995 19
1) Years are rounded from actual dates