Scaling Environmental Processes in Heterogeneous Arid Soils (SEPHAS)

Research Goal

To study environmental processes and properties of arid soils and how they may differ when observed at the benchtop compared to the landscape scale. This will help us to better understand water conservation and management, ground and surface water supply, improve erosion-, dust- and flood-control measures, and predict possible impacts of climate change on desert environments.

 

Research Questions

• How do arid climate conditions affect soil moisture and temperature?
• How deep does rainwater infiltrate into arid soil?
• How much rainwater can an arid soil store and make available for plants and other organisms?
• How do the microbial populations in desert soils react to changes in water content?
• Are desert soils carbon sinks or sources?
• How does soil heterogeneity influence water use and carbon uptake by desert ecosystems?
• What is the role of soil structure in water movement and plant uptake in arid settings?
• How does soil disturbance affect soil water flow and storage? Can a disturbed soil restore itself and how long does it take?
• Does wetting front instability occur in arid soils and, if yes, how does it affect fluid flow and transport process in the unsaturated zone?

 

Research Projects Related to SEPHAS

“The Solar-Energy-Water Nexus in Nevada”
G. Dana [DRI] and F. Harris [UNR] (Principal Investigators)
R. Boehm [UNLV], J.-M. Battista [UNLV], S. Dascalu [UNR] and M. Berli [DRI] (Co-Principal Investigators)
Supported by: NSF-EPSCoR Track 1 under grant no. IIA-1301726
Project duration: 06/1/2013-05/31/2021
Project website: https://solarnexus.epscorspo.nevada.edu/

The NEXUS project mission is to advance knowledge and discovery through research on solar technology, environmental impacts and associated water issues, and accelerate this research with new capabilities in cyberinfrastructure.

Intellectual Merit: (1) improved and novel technologies to minimize water use at solar energy facilities; (2) enhanced understanding of desert ecosystem responses to perturbations associated with development of solar energy facilities; (3) developed new advanced and sustainable water/wastewater approaches to support water needs for solar energy development; (4) improved reliability of renewable and solar energy supply with new interdisciplinary approaches; and (5) launched new CI capabilities including the Nevada Research Data Center, advanced data services, real-time data streaming and visualization, data mining and analysis, image processing, data security, and cloud computing.

Broader Impacts: (1) provided solar and micro-grid training to meet the staffing needs of local solar companies; (2) implemented education and outreach programs for governmental agencies to facilitate a better understanding of the solar plant approval process; (3) trained 18 teachers and educated more than 3,000 students on solar, water, and energy issues; and (4) increased NSHE wide in URM STEM degrees from 20% (2011-2012) to 35% (2017-2018). Underrepresented groups constitute 38% of project participants and 63% of those engaged externally. Females constitute 34% of project participants and 49% of those engaged externally; both of these percentages are much higher than those in current NV STEM faculty and student populations. Outreach by NEXUS scientists resulted in 62 collaborators external to Nevada (37 national, 25 international). Eight collaborators are from PUIs, 26 from HSIs, four from industry, four from National Laboratories, and 33 from government, school districts, or nonprofits.

As of the end of 2018, the NEXUS project has surpassed all of the milestones established for the project and approved by NSF. The NEXUS project has resulted in 178 peer-reviewed publications; 157 conference presentations; 170 submitted proposals with 72 funded projects totaling $63.2M; six new faculty hires; and two postdoctoral fellows. Of the students funded by the project, 41 graduate students have finished their degrees and 103 undergraduate students have finished their degrees.

 

“Root Induced Changes of Soil Physical Properties Using Synchrotron X-Ray Microtomography (CMT) and Micromechanical Simulations”

M. Berli (DRI, Principal Investigator)
T.A. Ghezzehei [UC Merced], P. Nico [LBNL] and S.W. Tyler [UNR] (Co-Principal Investigators)
Supported by: NSF Ecosystem and Hydrology programs under grant no. DEB-0817073
Project duration: 06/1/2008-05/31/2011
Project website: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0817073

The rhizosphere, i.e. the zone of soil immediately surrounding plant roots, plays a prominent role in supplying plants with water and nutrients. However, surprisingly little is known about rhizosphere physical properties and how they affect root growth, water and nutrient uptake. The lack of non-invasive and non-destructive imaging techniques necessary to observe living roots growing in undisturbed soil have been a main reason for this shortcoming. Recent advances in synchrotron X-ray microtomography (CMT) provide the potential to directly observe soil physical properties around living roots in-situ. Goal of the proposed study is to quantify rhizosphere physical properties by (1) employing CMT to visualize physical root-soil structure interactions, (2) simulating root-induced structural alterations using various micro-mechanical approaches (analytical, finite element, discrete element modeling), and (3) estimating changes in rhizosphere hydraulic properties (water retention and hydraulic conductivity functions) based on CMT imaging and inverse modeling. The proposed study seeks to provide transformative insights into the role of rhizosphere physical properties for water and nutrient uptake by living plants. It serves as a stepping stone for better understanding the role of plants in the critical zone at the soil-atmosphere interface. The project cuts across disciplinary boundaries of biology, soil physics, and soil mechanics to offer new insights on surface runoff, soil compaction and erosion, losses to agricultural productivity, land reclamation, and first-principles of soil-plant interactions.

 

“Scaling Environmental Processes in Heterogenous Arid Soils (SEPHAS)”

G. Dana (DRI, Principal Investigator)
M.H. Young [DRI], S.W. Tyler [UNR] and Z. Yu [UNLV] (Co-Principal Investigators)
Supported by: NSF EPSCoR Track 1 under grant no. EPS-0447416
Project duration: 06/1/2005-05/31/2008
Project website: https://www.dri.edu/sephas/

The goal of the Scaling Environmental Processes in Arid Soils (SEPHAS) program is to study environmental processes and properties of arid soils and how they may differ when observed at the benchtop compared to the landscape scale. We address this goal by developing a unique research facility in Nevada consisting of three large weighing lysimeters, a micrometeorological station as well as state of the art computational tools to study the hydrology of arid soils. In this way, SEPHAS helps us to better understand, protect and restore the fragile desert environments of Nevada and around the world, challenged by a burgeoning human population in increasingly arid landscapes. SEPHAS addresses specific questions such as (1) what is the moisture and temperature dynamics of an arid soil? (2) can disturbed arid soil restore itself? (3) what is the response of desert soil microbial populations to changes in water content? and (4) how does soil heterogeneity influence water use and carbon uptake by desert ecosystems?

Peer-reviewed journal articles

Luo, Y., T. A. Ghezzehei, Z. Yu and M. Berli (2020). “Modeling water redistribution in a dry desert soil.” Vadose Zone Journal: under review.

Lehmann, P., M. Berli, J. E. Koonce and D. Or (2019). “Surface evaporation in arid regions: Insights from lysimeter decadal record and global application of a surface evaporation capacitor (SEC) model.” Geophysical Research Letters 46(16): 9648-9657.

Dijkema, J., J. E. Koonce, R. M. Shillito, T. A. Ghezzehei, M. Berli, M. van der Ploeg and M. T. van Genuchten (2018). “Water Distribution in an Arid Zone Soil: Numerical analysis of data from a large weighing lysimeter.” Vadose Zone Journal 17.

Kelleners, T. J., J. Koonce, R. M. Shillito, J. Dijkema, M. Berli, M. H. Young, J. M. Frank and W. J. Massman (2016). “Numerical modeling of coupled water flow and heat transport in soil and snow.” Soil Science Society America Journal 80: 247–263.

Aravena, J. E., M. Berli, S. Ruiz, F. Suarez, T. A. Ghezzehei and S. W. Tyler (2014). “Quantifying coupled deformation and water flow in the rhizosphere using X-ray microtomography and numerical simulations.” Plant and Soil 376: 95-110.

Aravena, J. E., M. Berli, T. A. Ghezzehei and S. W. Tyler (2011). “Effects of root-induced compaction on rhizosphere hydraulic properties – X-ray micro-tomography imaging and numerical simulations.” Environmental Science & Technology 45(2): 425-431.

Caldwell, T.G., M.H. Young, and J. Zhu. 2008. Spatial structure of hydraulic properties from canopy to interspace in the Mojave Desert. Geophysical Research Letter 35: L19406, doi:10.1029/2008GL035095.

Marion, G.M. P.J. Verburg, E. V. McDonald, J. Arnone. 2008. Modeling salt movement through a Mojave Desert soil. Journal of Arid Environments 72(6): 1012-1033.

Wang, X.P. Y.X. Pan, Z. Yu, M.H. Young, 2008. Effects of rainfall characteristics on infiltration and redistribution patterns in revegetation-stabilized desert ecosystems. Journal of Hydrology 358(1-2): 134-143.

Young, M.H., G.S. Campbell, J. Yin. 2008. Correcting dual-probe heat-pulse readings for ambient temperature fluctuations. Vadose Zone Journal 7(1): 22-30.

Yin, J., M.H. Young, Z. Yu. 2008. Effects of Paleoclimate, Time-Varying Soil Properties and Time-Varying Canopy Structures on Paleorecharge. Journal of Geophysical Research – Atmospheres 113(D6): doi:10.1029/2007JD009010.

Meadows, D.G., M.H. Young, E.V. McDonald. 2007. Influence of Surface Age on Infiltration Mechanisms of Desert Pavements, Mojave Desert. Catena 72:169-178.

Wang, X.-P., M. H. Young, Z. Yu, and Z.-S. Zhang. 2007. Long-term effects of restoration on soil hydraulic properties in revegetation-stabilized desert ecosystems. Geophysical Research Letter doi:10.1029/2007GL031725.

Young, M. H., H. Lin, and B. P. Wilcox. 2007. Introduction to special section on Bridging Hydrology, Soil Science, and Ecology: Hydropedology and Ecohydrology. Geophysical Research Letter 34: L24S20, doi:10.1029/2007GL031998.

 

Books and book chapters

Aravena, J. E., M. Berli, M. Menon, T. A. Ghezzehei, A. K. Mandava, E. E. Regentova, K. K. Potteti, N. S. Pillai, J. Steude, M. H. Young, S. W. Tyler and P. S. Nico (2013). Synchrotron X-ray Microtomography (XMT) – New Means to Quantify Root Induced Changes of Rhizosphere Physical Properties. Soil–Water–Root Processes: Advances in Tomography and Imaging. S. H. Anderson and J. W. Hopmans. Madison, Soil Science Society of America: 39-68.

 

Theses

Luo, Y. (2020). Moisture Dynamics of a Near-Surface Desert Soil. Ph.D., University of Nevada Las Vegas.

Koonce, J. E. (2016). Water Balance and Moisture Dynamics of an Arid and Semi-Arid Soil: A Weighing Lysimeter and Field Study. Ph.D., University of Nevada Las Vegas.

Reineke, D. (2015). Numerical Simulation of Water, Heat and Vapor Flow in Weighable Lysimeters Under Arid Conditions. M.Sc., Technical University of Braunschweig.

Dijkema, J. (2014). Deserts: A Modeling Challenge – Where a Small Amount of Water is a Huge Deal. M.Sc., Wageningen University.

 

Reports

Chief, K., M. H. Young, B. F. Lyles, J. Healey, J. Koonce, E. Knight, E. Johnson, J. Mon, M. Berli, M. Menon and G. Dana (2009). Scaling Environmental Processes in Heterogeneous Arid Soils: Construction of Large Weighing Lysimeter Facility. Las Vegas, NV, Desert Reserach Institute: 370 p.

 

Conference papers and presentations

2020:

Or, D., P. Lehmann, S. Bickel and S. Fatichi (2020). Vegetation carrying capacity of arid regions: on the fraction of rainfall sheltered from surface evaporation. EGU General Assembly Online: EGU2020-6066.

 

2019:

Lehmann, P., S. Fatichi and D. Or (2019). Vegetation carrying capacity of arid regions deduced from rainfall fraction protected from surface evaporation. American Geophysical Union – Fall Meeting. San Francisco: EOS-Abstract No. H43A-04.

 

2018:

Berli, M., Y. Luo, T. A. Ghezzehei, J. E. Koonce, R. M. Shillito and M. B. Hausner (2018). Modeling water distribution in arid soil. W-3188 Multi-State Soil Physics Research Group. Las Vegas, NV, USDA.

Lehmann, P., M. Berli, J. E. Koonce and D. Or (2018). Modeling a decade-long record of evaporation and recharge dynamics in a deep desert soil lysimeter using the surface evaporation capacitor concept European Geosciences Union. Vienna, Austria, European Geosciences Union. 20: Geophysical Research Abstracts EGU2018-11412.

Luo, Y., J. E. Koonce, J. Dijkema, R. M. Shillito, T. A. Ghezzehei and M. Berli (2018). Modeling water redistribution in a near-surface desert soil. European Geosciences Union. Vienna, Austria, European Geosciences Union. 20: Geophysical Research Abstracts EGU2018-10733.

 

2017:

Iden, S. C., D. Reineke, J. E. Koonce, M. Berli and W. Durner (2017). Variably-saturated flow in large weighing lysimeters under dry conditions: parameter identification and predictive modelling using coupled water, vapor and heat flow theory European Geosciences Union. Vienna, Austria, European Geosciences Union. 19: Geophysical Research Abstracts EGU2017-10342.

Luo, Y., T. A. Ghezzehei, J. Koonce, J. Dijkema and M. Berli (2017). Modeling Water Redistribution in a Near-Surface Arid Soil American Geophysical Union – Fall Meeting. New Orleans, American Geophysical Union: EOS-Abstract No. H33D-1712

 

2016:

Dijkema, J., J. Koonce, T. A. Ghezzehei, R. M. Shillito, M. Berli, M. Van der Ploeg and M. T. Van Genuchten (2016). Water flow in arid soil: A comparison of weighing lysimeter data with simulations from a process-based model. W-3188 Multi-State Soil Physics Research Group. Las Vegas, NV, USDA.

Koonce, J. E., M. B. Hausner, M. Berli and M. H. Young (2016). Evaporation from bare arid soils: parameter estimation using Monte Carlo simulations. Geological Society of America Annual Meeting. Denver, CO, Geological Society of America. 48: 262-263.

Luo, Y., J. Koonce, R. Shillito, J. Dijkema, T. A. Ghezzehei, M. Berli and Z. Yu (2016). The impact of solar arrays on arid soil hydrology: some numerical simulations American Geophysical Union – Fall Meeting. San Francisco, CA, American Geophysical Union: EOS-Abstract No. H21C-1421.

 

2015:

Berli, M., J. Dijkema, J. Koonce, T. A. Ghezzehei, M. Van der Ploeg and M. T. Van Genuchten (2015). Liquid water and vapor flow in arid soil: comparison of weighing lysimeter data with simulations American Geophysical Union. San Francisco, CA, American Geophysical Union: EOS-Abstract no. H33B-1587.

Dijkema, J., J. Koonce, T. A. Ghezzehei, M. Berli, M. Van der Ploeg and M. T. Van Genuchten (2015). Simulating water flow and heat transfer in arid soil using weighing lysimeter data. European Geosciences Union. Vienna, European Geosciences Union. 17: EGU2015-8178.

Iden, S., D. Reineke, J. E. Koonce, M. Berli and W. Durner (2015). Variably-saturated flow in large weighing lysimeters under dry conditions: inverse and predictive modeling. European Geosciences Union. Vienna, European Geosciences Union. 17: EGU2015-9251.

Koonce, J., M. Berli, M. B. Hausner and M. H. Young (2015). Evaporation from bare arid soil: weighing lysimeter measurements and simulations. The Geological Society of America Annual Meeting. Baltimore, MA, The Geological Society of America: Paper no. 231-232.

 

2013:

Berli, M., T. A. Ghezzehei, M. Menon, P. S. Nico, S. W. Tyler and M. H. Young (2013). Unraveling Rhizosphere Physics Using X-ray Microtomography – Progress Report and Next Steps. W2188 Soil Physics. Las Vegas, NV.

 

2012:

Aravena, J. E., M. Berli, M. Menon, T. A. Ghezzehei, A. K. Mandava, E. E. Regentova, K. K. Potteti, N. S. Pillai, J. Steude, M. H. Young, S. W. Tyler and P. S. Nico (2012). Synchrotron X-ray Microtomography (XMT) – New Means to Quantify Root Induced Changes of Rhizosphere Physical Properties. Soil Science Society of America, Annual Meeting. Cincinnati, OH, Soil Science Society of America: Abstract no. 113-113.

Chief, K., M. H. Young, M. Berli, T. Caldwell, J. Daniels, J. Healey, B. Lyles and N. K. Twarakavi (2012). Evaluation of Seasonal and Annual Variations of Water Flow in Arid Soils Using Weighing Lysimeters. Soil Science Society of America International Annual Meeting. Cincinnati, OH, Soil Science Society of America: Abstract No. 266-216.

 

2011:

Aravena, J. E., S. Ruiz, A. K. Mandava, E. E. Regentova, T. A. Ghezzehei, M. Berli and S. W. Tyler (2011). Simulating root-induced rhizosphere deformation and its effect on water flow. American Geophycial Union, Fall Meeting. San Francisco, American Geophycial Union: EOS Abstract No. H51A-1182.

Berli, M., S. Ruiz, J. E. Aravena, L. Bolduc, T. A. Ghezzehei, D. P. Cook, A. K. Mandava, E. E. Regentova, M. Menon, P. S. Nico, S. W. Tyler and M. H. Young (2011). Exploring Rhizosphere Structure Alterations Using X-ray Tomography and Finite Element Calculations. DOE Subsurface Biogeochemical Research (SBR) Contractor-Grantee Workshop. Washington, DC, US Department of Energy, Office of Science.

Berli, M., S. A. Ruiz, J. E. Aravena, L. Bolduc, T. A. Ghezzehei, D. P. Cook, A. K. Mandava, E. E. Regentova, M. Menon, P. Nico, S. W. Tyler and M. H. Young (2011). Simulating rhizosphere structure alterations using finite element calculations. European Geoscience Union General Assembly. Vienna, Austria, European Geoscience Union. Vol. 13: EGU2011-13530.

Merkler, D., M. Berli and M. Stropky (2011). A Look At Southern Nevada’s Soil Moisture Sites During Rainfall Events; SNOTEL, SCAN and the Desert Research Institute SEPHAS Lysimeters. Soil Science Society of America, Annual Meeting. San Antonio, TX, Soil Science Society of America: Abstract no. 368-362.

Twarakavi, N., K. Chief, M. Berli, T. G. Caldwell, J. Daniels and M. H. Young (2011). Closing the Water Balance for Arid Soils – First Results from a Large Lysimeter Study. American Geophysical Union, Fall Meeting. San Francisco, CA, American Geophysical Union: H53A-1378.

 

2010:

Aravena, J. E., M. Berli and S. W. Tyler (2010). Rhizosphere compaction: Modeling a bed of multiple aggregates using x-ray micro-tomography information. American Geophysical Union, Fall Meeting. San Francisco, CA, American Geophysical Union: H52E-08.

Berli, M., T. A. Ghezzehei, M. Menon, P. S. Nico, S. W. Tyler and M. H. Young (2010). Unraveling Rhizosphere Physics Using X-ray Microtomography. W2188 Soil Physics. Las Vegas, NV.

Chief, K., M. H. Young and M. Berli (2010). Water infiltration into arid soils – first results from a lysimeter study. American Geophysical Union, Fall Meeting. San Francisco, CA, American Geophysical Union: H33E-1189

Ghezzehei, T. A., M. Berli, M. Menon, J. E. Aravena, N. S. Pillai, E. E. Regentova, S. W. Tyler, M. H. Young and P. Nico (2010). How do roots build a home in soil? 16thAnnual Coalition for National Science Funding Exhibition & Reception. Washington DC, CNSF.

 

2009:

Aravena, J. E., S. W. Tyler and M. Berli (2009). Effects of aggregate compaction on soil hydraulic properties due to root growth. American Geophysical Union, Fall Meeting. San Francisco, CA, American Geophysical Union.

Berli, M., M. Menon, T. A. Ghezzehei, P. S. Nico, S. W. Tyler and M. H. Young (2009). Root-induced changes in soil physical properties. W1188 Soil Physics. Oracle, AZ, University of Arizona Tucson.

Berli, M., M. Menon, T. A. Ghezzehei, N. S. Pillai, E. E. Regentova, P. S. Nico, M. H. Young and S. W. Tyler (2009). A Step Towards Unraveling Rhizosphere Physics. American Geophysical Union, Fall Meeting. San Francisco, CA, American Geophysical Union.

Berli, M., M. Menon, T. A. Ghezzehei, S. W. Tyler and M. H. Young (2008). Root induced changes in physical properties of desert soils. NWRA Natural Recharge Symposium. Las Vegas, NWRA.

Menon, M., M. Berli, T. A. Ghezzehei, P. S. Nico, M. H. Young and S. W. Tyler (2009). Visualizing rhizosphere soil structure around living roots. Micro Soil: Integrating Biological, Physical and Chemical Techniques for the Study of Soil Micro-Habitats. Dundee, Scotland, University of Abertay.

 

2008:

Berli, M., T. A. Ghezzehei, M. Menon, S. W. Tyler, M. H. Young and A. R. Dexter (2008). Modeling rhizosphere soil mechanics and hydraulics. ASA-CSSA-SSSA Annual Meeting. Houston, TX, ASA-CSSA-SSSA.

Berli, M., T. A. Ghezzehei, M. Menon, S. W. Tyler, M. H. Young and A. R. Dexter (2008). Modeling rhizosphere soil mechanics and hydraulics – an overview. Computational Methods in Water Resources XVII International Conference. San Francisco, Lawrence Berkeley National Laboratory.

Menon, M., M. Berli, T. A. Ghezzehei, P. S. Nico, M. H. Young and S. W. Tyler (2008). Visualizing rhizosphere soil structure around living roots. American Geophysical Union, Fall Meeting. San Francisco, American Geophysical Union.

Young, M. H., M. Berli, K. E., K. Chief, M. Menon, J. Mon, J. Healey, Z. Yu and S. W. Tyler (2008). Examining Arid Soil Processes in Nevada, USA, Using Weighing Lysimeters. Lysimeters for Global Change Research: Biological Processes and the Environmental Fate of Pollutants. Helmholtz Center, Munich, Germany.

 

2007:

Berli, M., M. Menon, T. A. Ghezzehei, S. W. Tyler and M. H. Young (2007). Multi-scale physical processes of desert soils – An example of Nevada EPSCoR research. National NSF EPSCoR MEETING. Kona, Hawaii, NSF EPSCoR.

Caldwell, T.G. M.H. Young, J. Zhu, E.V. McDonald. 2007. Small-Scale Heterogeneity of Soil Hydraulic Properties on Large-Scale Water Balance Simulations. American Society of Agronomy, New Orleans, LA.

Caldwell, T.G., M.H. Young, J. Zhu, L. Fenstermaker, E.V. McDonald. 2007. Scaling Heterogeneous Soil Hydraulic Properties Using Canopy/Interspace Distributions in a Mojave Desert Ecosystem. American Geophysical Union, Fall Meeting, San Francisco, CA.

Yin, J. M.H. Young, Z. Yu. 2007. Effects of Paleoclimate and Time-Varying Canopy Structures on Paleo-Water Fluxes. American Geophysical Union, Fall Meeting, San Francisco, CA.

Young, M.H. Measuring Water Content in Near-surface Soils With Large Changes In Ambient Temperature. Presented at the Environmental Sensors Symposium. Boise State University, Boise ID, Oct 26-27, 2007 (Invited).

Young, M.H., T.G. Caldwell, J.J. Miller, G. Dalldorf. 2007. Combining Pedotransfer Functions and Detailed Geomorphic Mapping to Characterize Runoff Potential on an Arid Alluvial Fan Complex. American Geophysical Union, Fall Meeting, San Francisco, CA.

Young, M.H. T.G. Caldwell, J. Zhu. 2007. Spatial Variability of Soil Hydraulic Properties at Interspace/Canopy Microsites. American Society of Agronomy, New Orleans, LA. (Invited)

Young, M.H., Z. Yu, S.W. Tyler. 2007. Large Weighing Lysimeters for Studying Environmental Processes in Arid Soils, Presented at the Unsaturated Zone Interest Group Meetings, Los Alamos, NM. August 27-29, 2007.

 

2006:

Caldwell, T.G., E.V. McDonald, M.H. Young, E.P. Hamerlynck, S.N. Bacon. 2006. Ecohydrology of an Arid Soil Chronosequence in the Sonoran Desert, Yuma Proving Ground, USA. American Geophysical Union, Fall Meeting, San Francisco, CA.

Meadows, D.G. M.H. Young, L. Fenstermaker. 2006. Impact of Spatial Variability of Soil Properties on Local Water Balance in a Mojave Desert Ecosystem. American Society of Agronomy, Indianapolis, IN.

Young, M.H. 2006. Evolution of soil hydraulic properties on arid alluvial fans: Impacts on near-surface water resources. Hohai University, Nanjing, China (Invited).

Young, M.H., D.G. Meadows, T.G. Caldwell, D.S. Shafer, E.V. McDonald. 2006. Evolution of soil hydraulic properties on arid alluvial fans. Presented at the AGU – Western Pacific Geophysics Meeting, Beijing, China (Invited).

Young, M.H. Z. Yu, S.W. Tyler. 2006. Scaling Environmental Processes in Heterogeneous Arid Soils (SEPHAS): A New Research Facility in Nevada USA. World Congress of Soil Science, Philadelphia, PA. (Invited).

Educational Opportunities

SEPHAS provides opportunities for undergraduate and graduate students as well as postdocs from Nevada, the US and around the world to conduct research on arid soil in collaboration with faculty from DRI as well as the Universities of Nevada Las Vegas (UNLV) and Reno (UNR). SEPHAS also benefits Nevada K-12 educators and students through “Science Alive”, DRI’s K-12 education program (https://www.dri.edu/science-alive/).

Outreach

SEPHAS provides a unique opportunity to see experimental research “at work”. Tours of the SEPHAS lysimeters in Boulder City are available by appointment. For more information, please contact Markus Berli (Markus.Berli@dri.edu).