Progress 09/01/09 to 08/31/14

Outputs
Target Audience: Water Resources Managers Scientists in various Earth and Agricultural Sciences Disciplines;e.g., Agricultural Water Resources Management, Hydrology, Critical Zone Science, Atmospheric Sciences, Soil Sciences, Remote Sensing, etc. Graduate and Undergraduate Students Postdoctoral Scholars Changes/Problems: Throughout this project we faced several personnel and technical problems, which led to delays. A PhD student, who devoted his dissertation research to this project, had to unexpectedly resign due to family reasons. A FLIR thermal camera, an integral part for this project, was damaged due to a lightning strike and was in repair for more than eight months. Lastly, the lysimeter facility in Tucson was flooded twice due to torrential monsoon rains. We did not significantly change the research plan, but had to adapt to the circumstances. During the final project year we collected a massive amount of field and laboratory data that we are currently analyzing and preparing for publication in refereed journals. What opportunities for training and professional development has the project provided? The project provided advanced training for several undergraduate and graduate students and two postdoctoral research scholars. Results of the lysimeter experiments were incorporated into the curricula of several courses taught at the University of Arizona (i.e. ENVS 470/570 and HWRS 250) and at Utah State University (i.e. PSC 5670/6670). We provided guided tours of the lysimeter facility and the experiment to undergraduate and graduate students at the University of Arizona and organized a field day for turf managers. How have the results been disseminated to communities of interest? Results were disseminated via refereed journal publications and a number of presentations at the Soil Science Society of America and American Geophysical Union Annual Meetings, the World Congress of Soil Science in South Korea, as well as at the annual University of Arizona EarthWeek and the Spring Runoff Conference at Utah State University. A number of refereed publications are currently under review and in preparation. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? We conducted a comprehensive laboratory and field measurement campaign to relate the thermal surface footprint to stage-1 evaporation (controlled by the atmospheric boundary) and predict the transition to stage-2 evaporation (controlled by soil hydraulic properties). We developed a new theoretical approach to predict evaporation rates from the thermal surface footprint and soil hydraulic properties of a reference soil using the measured duration of stage-1 evaporation as scaling factor. We conducted experiments to investigate effects of surface roughness on evaporation rates to develop potential strategies for evaporation suppression. In course of the project we also advanced heat-pulse technology for measurement of subsurface evaporation and water and vapor fluxes and developed a fully automated microlysimeter for continuous and prolonged measurement of soil evaporation.

Publications

• Type: Journal Articles Status: Published Year Published: 2014 Citation: Sadeghi, M., Tuller, M., Gohardoust, M.R., and Jones, S.B. (2014). Column-Scale Unsaturated Hydraulic Conductivity Estimates in Coarse-Textured Homogeneous and Layered Soils Derived under Steady-State Evaporation from a Water Table. Journal of Hydrology,519:1238-1248, doi:10.1016/j.jhydrol.2014.09.004.
• Type: Journal Articles Status: Under Review Year Published: 2014 Citation: Lv, L., Jones, S.B., and Hipps, L.E. (2015). Evapotranspiration Estimates in Four Common Vegetation Types in a Mountain Region of the Intermountain West. Ag. Forest Meteorology.
• Type: Journal Articles Status: Under Review Year Published: 2014 Citation: Rumana, K., Rattanapichai, W., Mace, R.W., Tuller, M., and Jones, S.B. (2014). A Fully Automated Microlysimeter for Prolonged Monitoring of Soil Evaporation. Soil Science Society of America Journal.
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Rumana, K., Tuller, M., and Jones, S.B. (2014). Determination of Subsurface Evaporation and Soil Water Content: Implementing a Heat Pulse Probe Array for High-Resolution Measurements. Soil Science Society of America Annual Meeting, Long Beach, CA, Nov. 2-5, 2014.
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Sadeghi, M., Tuller, M., and Jones, S.B. (2014). Effective Unsaturated Hydraulic Conductivity and Characteristic Length of Layered Soils Considering Steady-State Evaporation. Soil Science Society of America Annual Meeting, Long Beach, CA, Nov. 2-5, 2014.
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Sadeghi, M., and Jones, S.B. (2014). A Closed-Form Solution to Richards' Equation for Soil Evaporation and Concurrent Drainage. Soil Science Society of America Annual Meeting, Long Beach, CA, Nov. 2-5, 2014.
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Rumana, K., Tuller, M., and Jones, S.B. (2014). A Heat Pulse Probe Array for Subsurface Soil Evaporation Estimates. World Congress of Soil Science, Jeju, South Korea, June 8-13, 2014.
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Jones, S.B., Rumana, K., Sakai, M., Szafruga, P., and Tuller, M. (2014). A Multifunctional Heat Pulse Probe for Soil Physical Property and Process Assessment. World Congress of Soil Science, Jeju, South Korea, June 8-13, 2014.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Rumana, K., Tuller, M., and Jones, S.B. (2013). Resolving Heat Pulse Measurement Anomalies. Soil Science Society of America Annual Meeting, Tampa, FL, Nov. 3-6, 2013.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Rumana, K., Tuller, M., and Jones, S.B. (2013). In-situ Soil Water Content Estimates using a Heat Pulse Probe. Annual Spring Runoff Conference, Utah State University, Eccles Conference Center, Logan, UT, April 9-10, 2013.

Progress 09/01/11 to 08/31/12

Outputs
OUTPUTS: During the reporting period we completed a series of comprehensive laboratory experiments with a scaled weighing lysimeter and High-Resolution Thermal Imaging (HRTI) to measure thermal footprints of evaporating soil surfaces with textural contrasts and the water mass balance. We also initiated experiments with the same setup to measure evaporation from rough soil surfaces. The HRTI experiments were complimented by a second set of experiments where water mass balance was measured within an environmental chamber with precise temperature and humidity controls under uniform atmospheric boundary conditions. The results obtained with HRTI and chamber measurements are very promising and will provide useful for model evaluation and as guidelines for the large weighing lysimeter experiments. We also further advanced heat pulse technology and continued to work with a commercial partner to address some sensor issues related to thermistor failure and overall sensor longevity. Results were disseminated through a peer refereed publication in Water Resources Research and published abstracts and presentations at the annual international Soil Science Society of America (SSSA) meeting, the 2012 Spring Runoff Conference at Utah State University, and during the EarthWeek Conference at the University of Arizona. PARTICIPANTS: The collaborative project between the University of Arizona (UA) and Utah State University (USU) provided advanced training for a visiting scholar and three graduate students. USU visiting scholar Morteza Sadeghi Morteza worked on development of an analytical solution describing steady-state evaporation from a shallow water table. Aditya Kumar Verma, Ph.D. graduate research associate at UA contributed to laboratory and field experiments with high-resolution thermal imaging. Kashifa Rumana and Franyell Sifla, USU M.S. students, worked on the development and improvement of the PHPP array for measurement of subsurface evaporation. Scott White (UA) and Bill Mace (USU) assisted with experimental design, fabrication, and experiment setups. Dr. Dani Or (ETH Zurich, Switzerland) and Dr. Richard Allen (University of Idaho) provided valuable advice regarding experimental procedures and modeling. The PIs Markus Tuller (UA) and Scott Jones (USU) worked on all aspects of the project. TARGET AUDIENCES: Academic and Industrial Research; Federal and State Agencies Concerned with Soils and Environmental Protection; Stakeholders in Agriculture and Environmental Protection PROJECT MODIFICATIONS: Unfortunately we experienced another significant setback during the reporting period that will delay completion of the project. Aditya Kumar Verma, the UA PhD student working on the project discontinued his PhD program due to family reasons. At this point there are no project modifications planned, but we will apply for no-cost extension.

Impacts
Soil evaporation is an important component of the water balance in semiarid and arid regions. Insights gained from application of High-Resolution Thermal Imaging (HRTI) in conjunction with soil thermal property and energy balance measurements and coupled with physically-based modeling will provide new means to determine evaporation rates. When scaled to field and landscape scales the developed model can then be used to predict large-scale evaporation based on thermal satellite images. We envision that the information gained from our experiments will not only be useful for improving predictions of evaporation with large-scale climatic models, but also provide new insights for the development of advanced management strategies for reducing evaporation rates in urban, agricultural, and natural settings to conserve precious water resources in arid environments.

Publications

• Sadeghi, M., Shokri, N., and Jones, S.B. (2012). A Novel Analytical Solution to Steady-State Evaporation from Soil and Film Region Thickness. Water Resour. Res. 48 (9), W09516.
• Verma, A.K., Jones, S.B., and Tuller, M. (2012). Application of High-Resolution Thermal Imaging and Novel Heat Pulse Technology to Quantify Soil Evaporation. The University of Arizona EarthWeek Conference, Tucson, AZ, March 28-30, 2012.
• Sadeghi, M., and Jones, S.B. (2012). Modeling Steady-State Evaporation from a Shallow Water Table. Annual Spring Runoff Conference, Utah State University, Logan, UT, April 3-4, 2012.
• Verma, A.K., Jones, S.B., and Tuller, M. (2012). Application of High-Resolution Thermal Imaging and Novel Heat Pulse Technology to Quantify Soil Evaporation. ASA-CSSA-SSSA International Annual Meetings, Cincinnati, OH, Oct. 21-24, 2012.
• Sadeghi, M., Sakai, M., Tuller, M., and Jones, S.B. (2012). A New Algorithm for Determining Soil Evaporation Using Heat Pulse Probe Measurements. ASA-CSSA-SSSA International Annual Meetings, Cincinnati, OH, Oct. 21-24, 2012.
• Rumana, K., Jones, S.B., Tuller, M., and Sadeghi, M. (2012). Determination of Subsurface Soil Evaporation using a Heat Pulse Probe Array. ASA-CSSA-SSSA International Annual Meetings, Cincinnati, OH, Oct. 21-24, 2012.
• Rumana, K., Tuller, M., and Jones, S.B. (2012). Determination of Subsurface Soil Evaporation using a Heat Pulse Probe Array. 2012 Spring Runoff Conference, Utah State University, Logan, UT, April 3-4, 2012.
• Rumana, K., Rattanapichai, W., Jones, S.B., Mace, W., and Tuller, M. (2012). An Automated Microlysimeter for Long-Term Monitoring of Soil Evaporation. ASA-CSSA-SSSA International Annual Meetings, Cincinnati, OH, Oct. 21-24, 2012.

Progress 09/01/10 to 08/31/11

Outputs
OUTPUTS: During the reporting period we further advanced heat pulse technology, designing and fabricating a novel array of penta-needle heat pulse probes (PHPP) with SDI-12 communication capabilities. Each PHPP within the array is capable of determining soil temperature and thermal properties (conductivity and diffusivity) as well as providing calculated heat capacity and volumetric water content estimates at each depth increment. These measurements and calculated properties facilitate estimation of soil heat flux and sensible heat storage. Subsurface evaporation rates can be determined based on the sensible heat balance at a resolution of about 1 cm per day. We evaluated a 3-PHPP array in a large sand column where two different brands of soil heat flux plates were installed for comparison using an overhead industrial IR heat source. Preliminary evaporation estimates compared well with water mass balance measurements by means of a precision load cell. Availability of the new PHPP technology is not only important for the ongoing project, but also has significant impacts for other subsurface soil monitoring applications, for example in conjunction with weather stations and eddy covariance stations. Another important output was the development of a fully-automated, 60-cm deep microlysimeter mounted on a load cell for real-time measurement of water balance. The larger depth extends the useful monitoring period of the lysimeter beyond the approximately 10-day limit found with 30-cm lysimeters in previous studies. Preliminary laboratory and field results demonstrate the utility of the enhanced microlysimeter design. In addition, we conducted comprehensive laboratory experiments with High-Resolution Thermal Imaging (HRTI) using a scaled model of the large weighing lysimeters. For better interpretation of these experiments that were conducted with a varying atmospheric boundary we initiated a second set of experiments where water mass balance was measured within an environmental chamber with precise temperature and humidity controls under uniform atmospheric boundary conditions. The results obtained with HRTI and chamber measurements are very promising and will provide useful for model evaluation and as guidelines for the large weighing lysimeter experiments. Results to date were disseminated through a peer refereed publication in Water Resources Research and published abstracts and presentations at the annual international Soil Science Society of America (SSSA) and American Geophysical Union (AGU) meetings. PARTICIPANTS: The project, a collaboration between the University of Arizona (UA) and Utah State University (USU), provided advanced training for a postdoctoral research associate and two graduate students. Dr. Masaru Sakai, a postdoc at USU, contributed to testing of heat pulse technology and modeling of probe response. Matthew Stroud, M.S. graduate research assistant, and Aditya Kumar Verma, Ph.D. graduate research associate at UA contributed to laboratory and field experiments with high-resolution thermal imaging. Scott White (UA) and Bill Mace (USU) assisted with experimental design, fabrication, and experiment setups. Dr. Dani Or (ETH Zurich, Switzerland) and Dr. Richard Allen (University of Idaho) provided valuable advice regarding experimental procedures and modeling. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Unfortunately we also experienced a significant setback during the reporting period. A lightning strike during a heavy monsoon storm and the associated power surge caused substantial damage to the FLIR HRTI camera (despite surge protector) and prevented start of the lysimeter experiments. The camera is still with FLIR for evaluation and repair. At this point there are no project modifications planned. However, based on the outcome of the HRTI camera damage evaluation and potential costs for repair (up to $21K if the cooler needs to be replaced) we might be forced to suspend the planned HRTI experiments until funds to cover repair costs are found. Unfortunately, the University of Arizona does not carry insurance for potential equipment damage.

Impacts
Soil evaporation is an important component of the water balance in semiarid and arid regions. Insights gained from application of High-Resolution Thermal Imaging (HRTI) in conjunction with soil thermal property and energy balance measurements and coupled with physically-based modeling will provide new means to determine evaporation rates. When scaled to field and landscape scales the developed model can then be used to predict large-scale evaporation based on thermal satellite images. We envision that the information gained from our experiments will not only be useful for improving predictions of evaporation with large-scale climatic models, but also provide new insights for the development of advanced management strategies for reducing evaporation rates in urban, agricultural, and natural settings to conserve precious water resources in arid environments. Based on gained data we will be able to develop advanced surface covers for urban landscaping (e.g. hydrophobic mulches), or to recommend new surface preparation strategies for agricultural and environmental management (e.g., mechanical reduction of surface roughness) leading to a significant reduction of evaporation rates. Such strategies will not only reduce evaporation, but also significantly decrease irrigation requirements due to improved soil water storage.

Publications

• Sakai, M., Jones, S.B., and Tuller, M. (2011). Numerical Evaluation of Subsurface Soil Water Evaporation Derived from Soil Thermal Properties. Water Resour. Res., 47, W02547, doi:10.1029/2010WR009866.
• Jones, S.B., Sakai, M., and Tuller, M. (2011). Partitioning Evaporation and Infiltration Processes with an Array of Multifunction Heat Pulse Probes. Abstract H43P-06, AGU International Annual Meeting, San Francisco, CA, Dec. 5-9, 2011.
• Rattanapichai, W., Jones, S.B., Mace, R.W., and Tuller, M. (2011). An Automated Microlysimeter for Long-Term Monitoring of Soil Evaporation. Abstract 343-4, ASA-CSSA-SSSA International Annual Meetings, San Antonio, TX, Oct. 16-19, 2011.
• Jones, S.B., Sakai, M., and Tuller, M. (2011). A Penta-Needle Heat Pulse Probe Array for Soil Subsurface Evaporation and Heat Flux Estimates. Abstract 341-4, ASA-CSSA-SSSA International Annual Meetings, San Antonio, TX, Oct. 16-19, 2011.

Progress 09/01/09 to 08/31/10

Outputs
OUTPUTS: During the first project year a new heat pulse-based subsurface evaporation sensing system was developed. In order to understand the capabilities and limitations, a thorough laboratory tests were conducted in conjunction with a numerical modeling exercise to quantify the thermal and latent heat components of subsurface evaporation and to simulate evaporation estimates that are to be determined with a penta-needle heat pulse probe (HPP) technique. We prepared the UA weighing lysimeter facility for field testing and designed and built an automated gantry system for automated positioning of the High-Resolution Thermal Imaging (HRTI) system used to record surface heat signatures during the evaporation experiments. The system uses a bidirectional stepper motor and rail system fitted with a custom built trolley stabilizer and camera mount. First experiments will start in late fall 2010 or spring 2011 pending weather conditions. In addition, we conducted numerous HRTI experiments with a custom built and scaled lysimeter model in the laboratory. Results to date were disseminated through presentations and published abstracts at the annual international Soil Science Society of America (SSSA) and American Geophysical Union (AGU) meetings. In addition a manuscript was submitted for publication in a peer refereed international journal. PARTICIPANTS: Dr. Masaru Sakai, Postdoctoral Research Associate at Utah State University,contributed to testing and modeling of heat-pulse technology for prediction of subsurface evaporation. Matthew Stroud, Graduate Research Assistant at the University of Arizona, contributed to laboratory and field testing of the high-resolution thermal imaging system. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Bare-soil evaporation is an extremely important component of the water balance in semiarid and arid regions. Insights gained from application of High-Resolution Thermal Imaging (HRTI) in conjunction with soil thermal property and energy balance measurements coupled with physically-based modeling provides a novel approach to precision evaporation determination. When scaled to field and landscape scales these approaches can be used to predict large-scale evapotranspiration based on thermal satellite images. Information gained from our experiments can be applied to improve predictions of evaporation from large-scale climatic models. The project also provides novel insights for the development of advanced management strategies for reducing evaporation rates in urban, agricultural, and natural settings to conserve precious water resources in arid environments. Based on gained data we envision to develop advanced surface covers for urban landscaping (e.g. hydrophobic mulches), or novel surface preparation strategies for agricultural and environmental management (e.g., mechanical reduction of surface roughness) for significant reduction of soil evaporation rates. Such strategies not only reduce evaporation, but also significantly decrease irrigation requirements due to improved soil water storage.

Publications

• Sakai, M., Jones, S.B., and Tuller, M. (2010). Estimation of Evaporation Rates from a Subsurface Drying Front using a Penta-Needle Heat Pulse Probe. ASA-CSSA-SSSA Annual Meeting, Long Beach, CA, Oct. 31-Nov. 4, Agronomy Abstracts, ASA, Madison, WI. Sakai, M., Jones, S.B., and Tuller, M. (2009). Numerical Evaluation of Heat Pulse Technology for Estimation of Evaporation Rates from a Subsurface Drying Front. AGU Fall Meeting Abstracts, San Francisco, CA, December 14-18.