SWRC Sensor to Database Documentation

 

SWRC Soil Hydrology Data

 

Overview

A 27 year (1990-2017) soil hydrology database has been developed for the Southwest Watershed Research Center (SWRC). These sites encompass Walnut Gulch Experimental Watershed (WGEW), Audubon Research Ranch (ARR), Santa Rita Experimental Range (SRER), and the Upper San Pedro (USP) basin in southeastern Arizona. Data have been acquired at 3 automated weather stations, 7 TDR soil profile trench sites, and 52 locations dispersed across the southeastern Arizona co-located with recording rain gauges. Soil hydrology properties measured at the weather stations, trench sites, and rain gauges include soil moisture, soil temperature, soil heat flux, and soil surface temperature. Data are available at http://www.tucson.ars.ag.gov/dap. Modified from Keefer et al., 2008

Measured Variables

Keefer et al., 2008

Met/Soil Column Headers

Volumetric Water Content [%]

Soil Temperature at Depth [deg C]

Soil Surface Temperature [deg C]

Soil Heat Flux [W m-2]

Network Extent

Keefer et al., 2008

The SWRC soil hydrology network consists of sensors associated with 3 automated weather stations (AWSs), 7 soil profile trenches, and 52 near-surface soil hydrology sensors co-located with rain gauges in southeastern Arizona.

The 7 soil profile trenches and 2 of 3 AWS sites are located at 2 intensive rangeland study areas that are representative of the 2 main vegetative covers on WGEW: the shrub dominated Lucky Hills (LH) subwatershed (LHMet, LHTrench, TDRL1, and TDRL2) and the grass dominated Kendall (KEN) subwatershed (KNMet, KNTrench, KSTrench, TDRK1, and TDRK2) [Skirvin et al., 2008]. The third soil hydrology site associated with an AWS is located at the ARR, 42 km west of WGEW. Soil hydrology sensors co-located with SWRC rain gauges span WGEW, ARR, SRER, and USP (Table 1).

Table 1: SWRC soil hydrology sensor locations. Ground cover, soil series, and soil bulk densities are provided where available.




Site

LHMet

KNMet

ARRMet

LHTrench

KNTrench

KSTrench

TDRL1

TDRL2

TDRK1

TDRK2

WGEW

RG3

RG13

RG14

RG18

RG20

RG28

RG34

RG37

RG40

RG46b,c

RG57

RG69c

RG70

RG76

RG82b

RG83b

RG89

RG92c

RG100c

SRER

RG201

RG202

RG203

RG204

RG205

RG206

RG208

USP

RG400

RG401

RG402

RG403

RG404

RG405

RG406

RG407

RG408

RG409

RG410

RG411

RG412

RG413

RG414

RG415

RG416

RG417

RG418

RG419

 

RG420

RG421

RG422

RG423

RG424

RG426




Easting

589773

600231

547920

589798

600009

599892

589567

589793

599927

600012

 

581204

586110

585442

586710

587480

590624

590946

593303

593360

595289

596089

603916

604288

582624

600154

589679

596308

581888

593266

 

513036

512945

508238

509065

514046

513778

513969

 

582124

568321

568412

568806

568636

571258

573485

601853

569578

589990

605797

588104

598812

599874

561278

556530

560085

584702

575868

568576

 

567959

548540

544831

547920

558346

567342


UTM NAD83

Northing

3512434

3511719

3496185

3512418

3511756

3511855

3512290

3512420

3511822

3511754

 

3509768

3510185

3507187

3508098

3504939

3509990

3507458

3506068

3510286

3508655

3510781

3515463

3514207

3509679

3511680

3512426

3513931

3511774

3504720

 

3524541

3524350

3524192

3523927

3519959

3519800

3520124

 

3518828

3486006

3485884

3485822

3485822

3506843

3468309

3473471

3532305

3529727

3515697

3496282

3483402

3524258

3522768

3489184

3484923

3473697

3494594

3467898

 

3485736

3495059

3494627

3496185

3485444

3487870




Elevation

1370

1531

1453

1368

1515

1511

1366

1373

1504

1511

 

1246

1334

1390

1365

1525

1369

1420

1404

1390

1445

1446

1638

1630

1311

1530

1370

1491

1244

1418

 

1046

1049

970

897

1163

1215

1157

 

1258

1448

1447

1431

1437

1198

1512

1494

1097

1476

1854

1299

2171

2144

1466

2110

2299

1284

1286

2017

 

1409

1452

1492

1453

1409

1433




Cover

shrub

grass

grass

shrub

grass

grass

shrub

shrub

grass

grass

 

shrub

shrub

shrub

shrub

shrub

shrub

shrub

shrub

shrub

grass

grass

grass

grass

shrub

grass

shrub

grass

grass

shrub

 

*

*

*

*

*

*

*

 

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

 

*

*

*

*

*

*




Soil Seriesa

Luckyhills McNeal

Elgin-Stronghold

*

Luckyhills McNeal

Elgin-Stronghold

Elgin-Stronghold

Luckyhills McNeal

Luckyhills McNeal

Elgin Stronghold

Elgin Stronghold

 

Luckyhills McNeal

Monterosa

Chiricahua

Shiefflin

Mabray rock outcrop

Graham

Sutherland

Monterosa

Baboquivari-Combate

Clay loam

Tombstone

Blacktail

Woodcutter

Lampshire rock outcrop

Elgin-Stronghold

Luckyhills McNeal

Stronghold-Bernadino

McAllister Stronghold

Mabray rock outcrop

 

Combate-diaspar

Combate-diaspar

Agustin sandy loam

Hayhook-Pajarito

Sasabe-Baboquivari

Combate-diaspar

Sasabe-Baboquivari

 

Dona Ana-Mohave

Carbine

Carbine

Carbine

Carbine

Major

White House

Blakeney-Luckyhills

*

Budlamp-Woodcutter

Budlamp-Woodcutter

Riveroad and Ubik

Far-Hogris

*

Yarbam-Rock outcrop

Riveroad and Ubik

Blakeney-Luckyhills

Ubik

Bella

Rock outcrop-

Lithic Haplustolls

Carbine

White House gravelly loam

White House gravelly loam

White House gravelly loam

Far-Huachuca-Hogris

Gardencan-Lanque

Bulk
Density
5 cm
(g cm-3)

1.64

1.61

*

1.61

1.55

1.50

1.65

1.65

1.77

1.77

 

1.81

1.61

1.81

1.59

1.63

1.69

1.52

1.71

1.81

1.65

1.67

2.02

1.80

1.79

1.61

1.65

1.82

1.59

1.91

 

*

*

*

*

*

*

*

 

1.81

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

 

*

*

*

*

*

*

 

Modified from Keefer et al., 2008 Table 1

aAdditional soil texture information can be found in Table 1 of Keefer et al., 2008.

bThis rain gauge is equipped with additional soil moisture and temperature sensors at 15 and 30 cm.

cThis rain gauge is equipped with an IRT for soil surface temperature.

Instrumentation Specifications

Keefer et al., 2008

Table 2: SWRC soil hydrology site instrumentation specifications and periods of operation.


Site/Variable

LHMet and KenMet

  • Soil Moisture
  •  
  • Soil Temperature
  •  
  •  
  • Heat Flux

ARRMet

  • Soil Moisture
  • Soil Temperature
  • Heat Flux

Trench- LH, KN, KS

  • Soil Moisture
  •  

TDRL1

  • Soil Moisture
  •  
  • Soil Temperature
  •  

TDRL2

  • Soil Moisture
  •  
  •  
  •  
  •  
  •  
  •  
  • Soil Temperature
  •  
  •  
  •  

TDRK1

  • Soil Moisture
  •  
  • Soil Temperature
  •  

TDRK2

  • Soil Moisture
  •  

Rain Gauges

  • Soil Moisture 
  • Soil Temperature 
  •    


Instrument

 

 

 

  • TDR
  •  

 

  • TDR
  •  
  • Thermocouple
  •  

 

  • TDR
  •  
  • Thermocouple
  •  

 

  • TDR
  •  

 

Depth
(cm)

 

  • 5
  • 5, 15
  • 2,6
  • 1
  • Surface
  • 8

 

  • 5
  • 2,6
  • 8

 

  • 5, 10, 15,
  • 20, 30, 50

 

  • 5, 15, 30, 50,
  • 75, 100, 200
  • 5, 15, 30, 50,
  • 75, 100, 200

 

  • 5, 15, 30,
  • 50, 75, 100
  • 2.5, 5, 15, 30, 50
  • 5, 15, 30,
  • 50, 75, 100
  • 5, 15, 30,
  • 50, 75, 100
  • 5, 15, 30,
  • 50, 75, 100
  • 5, 15, 30,
  • 50, 75, 100

 

  • 5, 15, 30, 50,
  • 75, 100, 200
  • 5, 15, 30, 50,
  • 75, 100, 200

 

  • 2.5, 5, 10, 15,
  • 20, 30, 50, 75

 

  • 5, 15, 30*
  • 5, 15, 30*
  • Surface*


Period

 

  • 1996-2001
  • 2001-2017
  • 1996-2017
  • 2001-2017
  • 2004-2017
  • 1996-2017

 

  • 2003-2017
  • 2003-2017
  • 2003-2017

 

  • 1990-1998
  •  

 

  • 2003-2017
  •  
  • 2003-2017
  •  

 

  • 2008-2017
  •  
  • 2009-2017
  • 2009-2017
  •  
  • 2009-2017
  •  
  • 2003-2017
  •  
  • 2009-2017
  •  

 

  • 2004-2007
  •  
  • 2004-2007
  •  

 

  • 2009-2017
  •  

 

  • 2002-2017 
  • 2002-2017 
  • 2002-2017 

 

Modified from Keefer et al., 2008 Table 3

*All gauges contain 5 cm soil moisture. See Network Extent for gauges containing additional 15 cm soil moisture, 30 cm soil moisture, and surface temperature. Periods of operation vary between rain gauges.

Error/Accuracy Specifications

Keefer et al., 2008

Table 3: SWRC soil hydrology site error specifications, sampling resolution, and periods of operation.


Instrument

LHMet and KenMet

  • Soil Moisture
  • Soil Temperature
  • Thermocouple
  •  
  • Apogee IRT
  •  
  • Heat Flux

ARRMet

  • Soil Moisture
  • Soil Temperature
  • Thermocouple
  •  
  • Heat Flux

Trench- LH, KN, KS

  • Soil Moisture
  • TDR

TDRL1

  • Soil Moisture
  • TDR
  •  
  • Soil Temperature
  • Thermocouple
  •  

TDRL2

  • Soil Moisture
  • Soil Temperature
  • Thermocouple
  •  
  • Electric Resistance

TDRK1

  • Soil Moisture
  • TDR
  • Soil Temperature
  • Thermocouple

TDRK2

  • Soil Moisture
  • TDR

Rain Gaugesb

  • Soil Moisture 
  • Soil Temperature


Accuracy

 

  •  
  • ± 5%
  • ± 5%
  •  
  •  
  • ± 2° C
  •  
  • ± 5° C
  •  
  •  
  • ± 5%
  •  

 

  •  
  • ± 5%
  •  
  •  
  • ± 2° C
  •  
  •  
  • ± 5%
  •  

 

  •  
  • ± 5%

 

  •  
  • ± 5%
  •  
  •  
  • ± 2° C
  •  

 

  •  
  • ± 5%
  • ± 5%
  • ± 5%
  • ± 5%
  •  
  • ± 2° C
  •  
  • ± 5° C

 

  •  
  • ± 5%
  •  
  • ± 2° C

 

  •  
  • ± 5%

 

  •  
  • ± 5%
  •  
  •  
  • ± 5° C
  •  
  • ± 5° C
  •  

Output*
(Time, min.)

 

  •  
  • 20
  • 20
  • 30
  •  
  • 20
  • 30
  • 20
  • 30
  •  
  • 20
  • 30

 

  •  
  • 20
  • 30
  •  
  • 20
  • 30
  •  
  • 20
  • 30

 

  •  
  • various (days)a

 

  •  
  • 20
  • 30

 

  • 20
  • 30

 

  •  
  • 30
  • 30
  • 30
  • 30
  •  
  • 20
  • 30
  • 30

 

  •  
  • 20
  •  
  • 20

 

  •  
  • 30

 

  •  
  • 20
  • 30
  •  
  • 20
  • 30
  • 20
  • 30


Period

 

  •  
  • 1996-2001
  • 2001-2007
  • 2007-2017
  •  
  • 1996-2007
  • 2007-2017
  • 2004-2007
  • 2007-2017
  •  
  • 1996-2007
  • 2007-2017

 

  •  
  • 2003-2007
  • 2007-2017
  •  
  • 2003-2007
  • 2007-2017
  •  
  • 2003-2007
  • 2007-2017
  •  

 

  • 1990-1998

 

  •  
  • 2003-2007
  • 2007-2017
  •  
  • 2003-2007
  • 2007-2017

 

  •  
  • 2008-2017
  • 2008-2017
  • 2008-2017
  • 2008-2017
  •  
  • 2003-2007
  • 2007-2017
  • 2009-2017

 

  •  
  • 2004-2007
  •  
  • 2004-2007

 

  •  
  • 2009-2017

 

  •  
  • 2002-2007
  • 2007-2017
  •  
  • 2002-2007
  • 2007-2017
  • 2002-2007
  • 2007-2017

 

Modified from Keefer et al., 2008 Table 3

*Data sampling frequencies were dictated by the following ARS projects: Monsoon90 Experiment - 60 minutes, Installation of Bowen Ratio Systems - 20 minutes, and Installation of Eddy Covariance Flux Towers - 30 minutes.

aThese TDR soil moisture measurements were recorded manually using a Tektronix 1502B time-domain reflectometer. Measurement frequency varies.

bPeriods of operation vary between rain gauges.

installation and Maintenance

Keefer et al., 2008

The installation process for each soil profile trench was similar. A trench was excavated manually or with a backhoe. A small horizontal cavity, large enough to accept the soil moisture probe body, was created in the exposed trench face at the designated installation depth. Probes were inserted horizontally into this cavity, by pushing the probe tines into the soil at the recessed end of the cavity, until the probe head was within the cavity. The cavity was repacked with the soil that had been removed. Probe lead wires were run vertically down the trench face, across the bottom of the trench and up the other side, thus preventing preferential flow paths to probe head and tines. Multiple profiles were installed in the same trench, or in side by side trenches, under representative soil surface cover.

Although every attempt was made to assure good contact between soil and tines, it was impossible to know the extent of soil cracking around the tines at time of installation. Installation of soil temperature thermocouples in the same trenches was identical. Installation in the near surface, such as at the rain gauges and AWSs, of soil moisture, temperature and heat flux sensors was similar, but these shallow trenches were manually excavated and the soil surface was stabilized when installing very near to the surface, 1 and 2 cm. Proper installation is the initial step in data quality control. Taken from Keefer et al., 2008

Data Recording

LHMet, KenMet, and ARRMet

Soil hydrology measurements at SWRC meteorological stations record data using Campbell scientific dataloggers (CR1000 currently and CR10/CR10X historically) and multiplexers (AM16/32). Dataloggers are programmed using Campbell Scientific LoggerNet. CR10X dataloggers are programmed using EdLog and CR1000 dataloggers use CRBasic. While the programming languages differ in syntax, the logic and recording functions where shown to be interchangeable through thorough testing of the programs. Soil moisture, temperature, and heat flux sensors, are sampled every 10 seconds and averaged over the recording period (e.g., 15, 20, 30 min).

TDR Trenches - LH, KN, KS

TDR measurements for these profile trenches were recorded manually using Tektronix 1502B time-domain reflectometer. Data were then recorded onto data sheets and archived digitally.

TDR Profile Sites - TDRL1, TDRL2, TDRK1, TDRK2

Soil hydrology measurements at SWRC TDR profile sites record data using Campbell scientific dataloggers (CR1000 currently and CR10/CR10X historically) and multiplexers (AM16/32). Dataloggers are programmed using Campbell Scientific LoggerNet. CR10X dataloggers are programmed using EdLog and CR1000 dataloggers use CRBasic. While the programming languages differ in syntax, the logic and recording functions where shown to be interchangeable through thorough testing of the programs. Soil moisture and temperature are sampled at the end of the recording period (e.g., 15, 20, 30 min).

HydraProbe Sites Co-located with Rain Gauges

Soil hydrology measurements at co-located with rain gauges record data using Campbell scientific dataloggers (CR1000 and CR10X). Dataloggers are programmed using Campbell Scientific LoggerNet. CR10X dataloggers are programmed using EdLog and CR1000 dataloggers use CRBasic. While the programming languages differ in syntax, the logic and recording functions where shown to be interchangeable through thorough testing of the programs. Soil moisture and temperature are sampled at the end of the recording period (e.g., 15, 20, 30 min).

Data Collection/archiving

Keefer et al., 2008

Nichols and Anson, 2008

Met/Soil Column Headers

CR10X Manual

CR1000 Manual

LoggerNet Manual

Spread Spectrum Radio (RF400/RF450/451)

RavenXTV Cellular Modem

RF 310 VHF Radio and Modem

Shortly after midnight on a daily basis, data from the WGEW sites are downloaded automatically via telemetry and are transmitted to a computer at the SWRC Tombstone field office. VHF, spread spectrum, and cellular modems are used depending on the geographic location of the gauge. Raw data are archived in the Tombstone office and a series of batch processes are executed using LoggerNet to parse out relevant data to be processed in Tucson and to generate daily maintenance reports. The daily data are then transfered to a SWRC server residing in Tucson. Modified from Nichols and Anson., 2008

Data Processing

Data are processed quarterly using a combination of LoggerNet and Fortran processes.

QA/QC

The initial data stream from field sites may contain missing values for any property because the station was not in operation intentionally or accidentally, the sensor was not deployed at that time, or there was data collection, communication or computer failure. Data determined to be collected during periods when a sensor was known to be inoperable (e.g., vandalism, animal or natural interference) were coded with missing values.

Incoming data, after transformation from measured value to final units, if applicable, are screened by automated and visual graphic processes for outliers beyond acceptable limits. Outliers that are physically impossible (e.g., negative soil moisture) are coded as missing. Taken from Keefer et al., 2008

Database Archiving

The raw data is archived daily in an SQLServer database once received at the SWRC Tucson office. Once the data has been processed and QA/QC'd (quarterly) it is archived locally and served from the SWRC FTP site, accessible from the SWRC Online Data Access Project Site (DAP) in csv format.

Data Access

SWRC meteorological data can be accessed at the following websites:

SWRC Online Data Access (DAP) - QA/QC'd data updated approximately every 90 days

USDA Long-Term Agroecosystem Research Network - 15-min data updated daily (provisional data)

USDA National Agricultural Library Ag Data Commons - DAP mirror

 

Data Use Agreement

All data available through the SWRC data access website are in the public domain, and are not restricted by copyright.

 

The SWRC will review the research results to ensure sound scientific data interpretation in the context of our historical results and our in situ experience with these data. We expect that our support will be acknowledged through co-authorship and formal acknowledgment of field and/or data support in the manuscripts (see example below).

 

Datasets were provided by the USDA-ARS Southwest Watershed Research Center. Funding for these datasets was provided by the United States Department of Agriculture, Agricultural Research Service.

 

Please send 1 copy of the published manuscript to:

Southwest Watershed Research Center

2000 E. Allen Rd.

Tucson, AZ 85719

Known Data Issues

  • Soils data is not in the SWRC database.
  • No standard semi-automated QA/QC procedure is in place.
  • Need to update sensor timeline and on/off dates.
  • Consistency with spatial averaging and replications.
  • Salinity and electric conductivity not processed from HydraProbes.
  • Monsoon 90 TDR Trench soil temperatures not processed.
  • Not all L2 and K2 data are processed for DAP.
  • SRER and USPP HydraProbe locations need to be added to Keefer et al., 2008 Table 1.
  • Shallow sensor depths may have been altered from erosion. Actual depths currently unknown and may vary with time.
  • High rock content in soils makes installation at precise depth difficult and increases uncertainty in soil moisture measurements.
  • Examples of Data Use

    Colliander et al., 2017

    Goodrich et al., 1994

    Moran et al., 2009

    Stillman et al., 2014

    Validation and scaling of soil moisture in a semi-arid environment: SMAP validation experiment 2015 (SMAPVEX15)

     

    Runoff simulation sensitivity to remotely sensed initial soil water content

     

    Partitioning evapotranspiration in semiarid grassland and shrubland ecosystems using time series of soil surface temperature

     

    Summer soil moisture spatiotemporal variability in Southeastern Arizona

    References and KEY Literature

    Anson, E. and Wong, J. (2005a). Process DAP Documentation. SWRC Internal Report.

     

    Anson, E. and Wong, J. (2005b). DAP Access Database Description. SWRC Internal Report.

     

    Armendariz, G., ??? (2016). DAP QA/QC processes followed at Walnut Gulch Experimental Watershed. SWRC Internal Report

     

    Brakensiek, D. L., Osborn, H. B., & Rawls, W. J. (1979). Field manual for research in agricultural hydrology. Field manual for research in agricultural hydrology.

     

    Colliander, A., Cosh, M.H., Misra, S., Jackson, T.J., Crow, W.T., Chan, S., Bindish, R., Chae, C., Holifield Collins, C., Yueh, S.H. 2017. Validation and scaling of soil moisture in a semi-arid environemnt: SMAP validation experiment 2015 (SMAPVEX15). Remote Sensing of Environment. 196: 101-112.

     

    Goodrich, D.C., Schmugge, T.J., Jackson, T.J., Unkrich, C.L., Keefer, T.O., Parry, R., Bach, L.B., Amer, S.A. 1994. Runoff simulation sensitivity to remotely sensed initial soil water content. Water Resour. Res. 30:1393-1405.

     

    Keefer, T.O., Moran, M.S., Paige, G.B. 2008. Long-term meteorological and soil hydrology database, Walnut Gulch Experimental Watershed, Arizona, United States. Water Resources Research, Vol. 44, W05S07.

     

    Moran, M.S., Scott, R.L., Keefer, T.O., Emmerich, W.E., Hernandez, M., Nearing, G.S., Paige, G.B., Cosh, M.H., O'Neill, P.E. 2009. Partitioning evapotranspiration in semiarid grassland and shrubland ecosystems using time series of soil surface temperature. J. Ag. and Forest Meteorology. 149:59 72.

     

    Paige, G.P., Keefer, T.O. 2008. Field application performance of multiple soil moisture sensors. Journal of the American Water Resources Association (JAWRA) 44(1):121-135.

     

    Schmugge, T., Jackson, T.J., Kustas, W.P., Roberts, R., Parry, R., Goodrich, D.C., Amer, S.A., Weltz, M.A. 1994. Push broom microwave radiometer observations of surface soil moisture in Monsoon '90. Water Resour. Res. 30(5):1321-1327.

     

    Stillman, S., Ninneman, J., Zeng, X., Franz, T., Scott, R.L., Shuttleworth, W.J., Cummins, K. 2014. Summer soil moisture spatiotemporal variability in Southeastern Arizona. Journal of Hydrometeorology. 15:1473-1485.

     

    Smith, J.R. (2017) Instrumentation Protocol. SWRC Internal Report

     

    CR10X Measurement and Control Module Operator's Manual Rv. 02/2003

     

    CR1000 Datalogger Operator's Manual Rv. 12/2016

     

    LoggerNet Version 4.4 Instruction Manual Rv. 02/2016

     

    RF400/RF410/RF415 Spread Spectrum Radio/Modem Manual Rv. 03/2015

     

    RF450 Spread Spectrum Radio Manual Rv. 04/2015

     

    RavenXTV CDMA Sierra Wireless Cellular Modem Manual Rv. 03/2017

     

    RF451 Spread Spectrum Radio Manual Rv. 05/2017

    USDA-ARS SWRC | Draft 4/16/2018 | Mark Kautz