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Additional Biographical Information for Green, Timothy
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Past Accomplishments of Investigator - Timothy R. Green

 

EDUCATION

1986 B.S. Civil Engineering, University of Washington, Seattle, WA

1989 M.S. Civil Engineering/Water Resources, StanfordUniversity, Stanford, CA

1995 Ph.D. Civil Engineering/Hydrology, StanfordUniversity, Stanford, CA

 

RESEARCH EXPERIENCE

1991-94 Hydrologist, USGS, Water Resources Division, Menlo Park, CA

1995-97 Research Scientist, CSIRO, Div. Water Resources, Perth, Australia

1997-98 Senior Research Scientist, CSIROLand & Water, Perth, Australia

1999-Present Agricultural Engineer, USDA-ARS, GPSR/ASR Unit, Fort Collins, CO

2005 Guest Professor, ETH Institute for Terrestrial Ecology, Z?rich, Switzerland

 

ACCOMPLISHMENTS

1.    Derived new stochastic/numerical results for moisture-dependent directional hydraulic conductivity, showing how soil heterogeneity and landscape undulations can cause preferred, unsaturated pathways for lateral convergence and deep drainage.

2.    Identified spatial scaling relationships of crop yield, soil water, infiltration, and landscape topography on instrumented farm fields using fractal geometry to characterize the behavior of observed variability across management scales. 

3.    Identified fractal scaling relationships of pesticide concentrations in streams. This resulted from an invitation to join an industry-led team of scientists, including Monsanto, Bayer, and USGS (2001-2003).

4.    Simulated soil-plant water dynamics from climate scenarios, then derived statistical measures, including the temporal persistence, for assessing the potential impacts of forecasted climate change on groundwater recharge. This work has led to becoming a member of the UNESCO International Hydrological Program (IHP) expert panel to conceive a new international project called GRAPHiC (Groundwater Resources Assessment under the Pressures of Humanity and Climate change), 2004-present.

5.    Developed a Spatial Analysis Neural Network (SANN) method for predicting spatial patterns of crop grain yield from topographic attributes. This method showed significant improvements over multiple linear regression for all fields.

6.    Evaluated effects of digital elevation accuracy and resolution on computed topographic attributes, including potential contributing area, where five algorithms were compared quantitatively.

7.    Derived an empirical equation for the permittivity of environmental media from resonant frequency measurements of capacitance sensors for estimation of soil water content. This work was initiated at the ETH, Institute for Terrestrial Ecology, Z?rich, Switzerland, January-July 2005 (fully funded by the ETH). The results will be used to assess temperature effects on the apparent soil water content in the field.


RELEVANT PEER-REVIEWED PUBLICATIONS

1.    Green, T.R., R.E. Green and M.E. Miller. Impacts of vertical heterogeneity on simulated flow in Hawaiian basaltic saprolite: Relation to recharge, Advanced Series in Agricultural Sci., 20:233-246. 1993.

2.    Green, T.R. and D.L. Freyberg.  State-dependent anisotropy: Comparisons of quasi-analytical solutions with stochastic results for steady gravity drainage, Water Resour. Resear., 31(9):2201-2211. 1995.

3.    Green, T.R., J.E. Constantz and D.L. Freyberg.  Upscaled water retention using van Genuchten's function, ASCE J. Hydrol. Engr., 1(3):123-130. 1996.

4.    Dietrich, C.R., T.R. Green and A.J. Jakeman.  An analytical model for stream sediment transport: application to the Murray and MurrumbidgeeRiver reaches, Hydrol. Process., 13(5):763-776. 1999.

5.    Green, T.R., S.G. Beavis, C.R. Dietrich and A.J. Jakeman. Relating observed stream-bank movement to in-stream transport of suspended sediment, Hydrol. Process., 13(5):777-787. 1999.

6.    Green, T.R. and M. Sivapalan, Eds. Special Issue: Process Interactions in the Environment, Hydrol. Process., 13(5):632-840. 1999.

7.    Jakeman, A.J., T.R. Green, S.G. Beavis, C.R. Dietrich, L. Zhang and P.F. Crapper.  Modelling upland and instream erosion, sediment and phosphorus transport in a large catchment, Hydrol. Process., 13(5):745-752. 1999. 

8.    Western, A.W., R.B. Grayson and T.R. Green. The Tarrawarra Project: High resolution spatial measurement, modelling and analysis of hydrological response, Hydrol. Process., 13(5):633-652. 1999.

9.    Ruan, H., L.R. Ahuja, T.R. Green and J.G. Benjamin. Residue cover and crusting effects on infiltration: numerical simulations for field applications, Soil Sci. Soc. Am. J., 65:853-861. 2001.

10.  Green, T.R., L.R. Ahuja, and J.G. Benjamin. Advances and challenges in predicting agricultural management effects on soil hydraulic properties in space and time, Geoderma,116(1-2):3-27. 2003.

11.  Green, T.R. and R.H. Erskine. Measurement, scaling, and topographic analyses of spatial crop yield and soil water content, Hydrol. Process. 18:1447-1465. 2004.

12.  Gustafson, D.I., K.H. Carr, T.R. Green, C. Gustin, R.L. Jones and R.P. Richards.  Fractal-based scaling and scale-invariant dispersion of peak concentrations of crop protection chemicals in rivers, Envirnomental Sci. & Tech. 38(11):2995-3003. 2004.

13.  Martinez, A., J.D. Salas and T.R. Green.  Sensitivity of spatial analysis neural network training and interpolation to structural parameters, Math. Geology 36(6):721-742. 2004.

14.  Kozak, J.A., L.R. Ahuja, L. Ma, and T.R. Green. Scaling and estimation of evaporation and transpiration of water across soil texture classes. Vadose Zone J., 4: 418-427. 2005.

15.  Salas, J.D., H.S. Kim, R. Eykholt, P. Burlando and T.R. Green. Aggregation and sampling in deterministic chaos: Implications of the dynamics of hydrological processes, Nonlinear Processes in Geophysics 12: 557-567. 2005.

16.  Hu, C., S. A. Saseendran, T. R. Green, L. Ma, X. Li, and L. R. Ahuja. Evaluating nitrogen and water management in a double-cropping system using RZWQM. Vadose Zone J., 5: 493-505. 2006.

17.  McCutcheon, M.C., H.J. Farahani, J.D. Stednick, G.W. Buchleiter and T.R. Green. Effect of soil water on apparent soil electrical conductivity and texture relationships in a dryland wheat-fallow field. Biosystems Engineering 94 (1):19-32. 2006.

18.  Meng, H., J.D. Salas, T.R. Green and L.R. Ahuja.  Scaling analysis of space-time infiltration based on the universal multifractal model. J. Hydrology 322:220-235. 2006.

19.  Yu, Q.,S.A. Saseendran, L. Ma, G.N. Flerchinger, T.R. Green, L.R. Ahuja.  Modeling a wheat-maize double cropping system in China using two plant growth modules in RZWQM. Agric. Systems 89:457-477. 2006.

20.  Erskine, R.H., T.R. Green, J.A. Ramirez and L. MacDonald. Comparison of grid-based algorithms for computing upslope contributing area, Water Resources Research 42, W09416, doi:09410.01029/02005WR004648. 2006.

21.  Schwank, M., T.R. Green, C. M?tzler, H. Benedickter, and H. Fl?hler.  Laboratory characterization of a commercial capacitance sensor for estimating permittivity and inferring soil water content.Vadose Zone J. 5:1048-1064. 2006.

22.  Kozak, J.A., L.R. Ahuja, T.R. Green, and L. Ma.  Modelling crop canopy and residue rainfall interception effects on soil hydrological components for semi-arid agriculture, Hydrological Processes 20: 229-241. 2007.

23.  Andales, A.A., T.R. Green, L.R. Ahuja, R.H. Erskine, and G.A. Peterson. Temporally stable patterns in grain yield and soil water on a dryland catena. Agric. Systems 94:119-127. 2007.

24.  Green, T.R., J.D. Salas, A. Martinez, and R.H. Erskine. Relating crop yield to topographic attributes using spatial analysis neural networks and regression.Geoderma, 139:23-27. 2007.

25.  Erskine, R.H., T.R. Green, J.A. Ramirez, and L.H. MacDonald. Digital elevation accuracy and grid cell size: effects on computed topographic attributes. Soil Sci. Soc. Amer. J. 71:1371-1380. 2007.

26.  Schwank, M. and T.R. Green.  Simulated effects of soil temperature and salinity on capacitance sensor measurements. Sensors J. 7:548-577. 2007.

27.  Green, T.R., B.C. Bates, S.P. Charles and P.M. Fleming. Physically based simulation of potential effects of carbon dioxide altered climates on groundwater recharge, Vadose Zone J. 6:597-609. 2007.

28.  Green, T.R., M. Taniguchi, and H. Kooi. Potential impacts of climate change and human activity on subsurface water resources. Vadose Zone J. 6:531-532. 2007.

29.  Meng, H., T.R. Green, J.D. Salas, and L.R. Ahuja. Development and Testing of a Terrain-Based Hydrologic Model for Spatial Hortonian Infiltration and Run-Off/On. Environ. Model. & Software 23:794-812. 2008.

30.  Strudley, M.W., T.R. Green, and J.C. Ascough II. Tillage effects on soil hydraulic properties in space and time:  State of the science. Soil & Tillage Research. 99:4-48. 2008.

31.  Green, T.R., G.H. Dunn, R.H. Erskine, J.D. Salas, and L.R. Ahuja. Fractal analyses of steady infiltration and terrain on an undulating agricultural field, Vadose Zone J. 8(2): ---. 2009 (in press).