CHARACTERIZATION AND MODELING OF THE MULTI-SCALE HYDROLOGY SYSTEM

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0202599
• Project Start Date: Oct 1, 2009
• Project End Date: Sep 30, 2014
• Program Code: [(N/A)]- (N/A)

Recipient Organization
PURDUE UNIVERSITY
(N/A)
WEST LAFAYETTE,IN 47907

Performing Department
Ag & Biological Engineering

Non Technical Summary
This research presents a systemic process-based approach to characterize and parameterize the soil medium using its volume change. It has significant implications on water flow, contaminant transport, and soil water management. This approach can be used to accurately define and quantify commonly used agronomic properties that are empirical up until now. The study demonstrated a unique link between soil water properties of non-rigid aggregated soil medium and its internal volume change. This link leads to a physically-based and functional model of the soil medium. This medium is uniquely and accurately characterized by the shrinkage curve, swelling curve, and the tensiometric that are simultaneously and continuously measured.

Animal Health Component

30%

Research Effort Categories

Basic

50%

Applied

30%

Developmental

20%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
101	0110	2020	33%
102	0210	2050	33%
405	0320	2061	34%

Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 405 - Drainage and Irrigation Systems and Facilities; 101 - Appraisal of Soil Resources;

Subject Of Investigation
0320 - Watersheds; 0110 - Soil; 0210 - Water resources;

Field Of Science
2020 - Engineering; 2050 - Hydrology; 2061 - Pedology;

Keywords

multiscale hydrology

hydropedology

hydrology

soil water interaction

soil water characterization

soil water modeling

Goals / Objectives
The overall goal of this project is to create a framework in which multi-scale hydrologic processes are connected and where information flows from the local processes scale to the landscape scale and vice versa. Large-scale policy and activities impact local processes. Similarly, local processes have large - scale impact. Specific objectives of this project are to: 1. Develop the pedostructure model (Kamel(R) and the companion characterization software KamelSoil(R)), and evaluate the model using field data from Indiana, Montana, and Montpellier (France). 2. Develop a scale up methodology to expand the pedostructure concept from the plot to watershed scales

Project Methods
Objective 1: We will apply Kamel(R) model for simulating a field drainage conditions starting from two sets of parameters: i) pedohydral parameters calculated from the soil characteristics, namely, the tensiometric and conductivity curves, and the bulk density at every 30 cm depth; and ii) pedohydral parameters calculated using KamelSoil(R) from soil characteristics estimated according to the pedotransfer functions gathered by Saxton and Rawls (2006). In partnerships with Dr. Heathman research group at the NSERL West Lafayette, we will measure field water redistribution and drainage following saturation of the soil profile. The soil characteristics include 1) the water potential curve in the range 0 to 50 kPa, which was measured in the laboratory on soil core samples; 2) the bulk density; and 3) the two parameters of the exponential form of the conductivity equation, k = ksat exp [a (θ-θsat)], that were considered unvarying for the whole profile. The field measurements consisted of soil water suction recorded from tensiometers located at 30-cm depth increments for the Yolo soil. Soil water suction measurements from the tensiometers were used then with soil water characteristic curves to estimate the soil water content and the soil water flux at each soil depth. We will approach these field data using Kamel(R), according to the characteristic information about Yolo soil. For comparison, these soil characteristics estimated using KamelSoil(R) on the basis of the texture will also be used for the simulation. Objective 2: Hydrologic scaling and transfer across scales is one of the major challenges facing the soil and water discipline. This project leads the development of a unique modeling paradigm that allows improved field water management through greater accuracy of prediction of contaminant transport and transfer, and incorporation of over-burden pressure in the representative element structural volume. The modeling tools being developed in this project characterize the soil water medium using shrinkage, swelling, water potential properties and the stress-strain relationships within the medium. It also provides a systematic procedure for up-scaling the local soil water medium (pedostructure) processes to the pedon, field, and watershed scales. An integrated laboratory - field and modeling activities to help characterize and model the multi-scale system - is underway. Laboratory measurements of stresses, water potential, volume change, conductivity are being conducted to characterize soil water dynamics. These measurements are being used to conceptualize a soil water medium representation. Field measurements are collected to help develop crossing scales relationships and to evaluate the modeling tools being developed. In addition to the impact on the scientific community and the numerous technical publications completed, this work has been introduced in the classroom and found to be very effective in addressing issues of scale to users/students (Mohtar et al 2007).

Progress 10/01/09 to 09/30/14

Outputs
OUTPUTS: During the reporting period Dr. Mohtar moved into a university administrative position and terminated his research activities. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Research activities were suspended during the reporting period.

Publications

• No publications reported this period

Progress 10/01/10 to 09/30/11

Outputs
OUTPUTS: 1. Organized two meetings for the US - French Bilateral Partnerships on water, food, and climate change at Purdue Campus (May 2010) and Montpellier, France (July 2011). The system's approach developed by Mohtar and his colleagues, were the catalysts of these discussions. These symposia have generated twelve projects and partnerships, a proceeding, and special issue of Computer and electronics in Agriculture. 2. Participated in a water security symposium in Muscat, Oman and were awarded a seed funding for a regional project on multi-scale hydrology. 3. Helped organize a workshop on multi-scale hydrology in Tunisia 4. Several refereed publications and grants in the multi-scale hydrology area PARTICIPANTS: Scientist from various natural resources disciplines TARGET AUDIENCES: Primarily hydrologists modeling climate change and water use. PROJECT MODIFICATIONS: Updated Non-Technical Summary: This research presents a systemic process-based approach to characterize and parameterize the soil medium using its volume change, hydraulic potential, and conductivity continuously measured. It has significant implications on water flow, contaminant transport, and soil water management. This approach can be used to accurately define and quantify commonly used agronomic properties that are empirical up until now, such as air entry, wilting point, field capacity, etc. The study demonstrated a unique link between soil water properties of non-rigid aggregated soil medium and its internal volume change and other hydrodynamic properties such as conductivity and water potential. This link leads to a physically-based and functional model of the soil medium. This medium is uniquely and accurately characterized by the shrinkage, swelling, hydraulic conductivity, and tensiometric curves that are simultaneously and continuously measured. Updated Objectives: The overall goal of this project is to create a framework in which multi-scale hydrologic processes are connected and where information flows from the local processes scale to the landscape scale and vice versa. Large-scale policy and activities impact local processes. Similarly, local processes have large-scale impact. Specific objectives of this project are to: 1. Develop the pedostructure model (Kamel(R) and the companion characterization software KamelSoil(R)), and evaluate the model using field data from Indiana, Montana, Montpellier (France), and the Arabian Gulf states. 2) Develop a scale-up methodology to expand the pedostructure concept from the plot to watershed scales.

Impacts
The modeling technology is changing the way researchers characterize and model porous media and has been adopted by one of Europe's largest agronomic modeling projects: SEAMLESS (System for Environmental and Agricultural Modeling: Linking European Science and Society). This work on pedostructure is recognized as pioneering in the emerging field of hydropedology (which integrates hydrology, soil physics, and pedology). A new white paper was adopted using this approach at the US-French bilateral conference at Purdue in May of 2010.

Publications

• Dare, A.E. and Mohtar, R.H. 2011. Global Design Team: A Global Service-Learning Experience. International Journal of Engineering Education. Vol. 28, No. 1, pp. 1-14.
• J.J. Mallory, R.H. Mohtar, G.C. Heathman, D.G. Schulze, and E. Braudeau. 2011. Evaluating the Effect of Tillage on Soil Structural Properties Using the Pedostructure Concept. Geoderma. Vol. 163, Issues 3-4, July 15, pp. 141-149. doi:10.1016/j.geoderma.2011.01.018
• J. Anmala and R.H. Mohtar. 2011. Fourier Stability Analysis of Two-Dimensional Finite Element Schemes for Shallow Water Equations. International Journal of Computational Fluid Dynamics. 25, 2. February. pp. 75-94, doi:10.1080/10618562.2011.560572
• Darwish, M.A., Elesheky, M.E., and Mohtar, R.H. 2011. Desalting Seawater in Qatar by Solar Energy: A Feasibility Study. Workshop: Power Electronics for Industrial Applications and Renewable Energy Conversion. Doha, Qatar. November 3-4.
• Darwish, M.A., and R.H. Mohtar. 2011. Qatar Water Problem. Conference on Desalination for the Environment Clean Water and Energy. Barcelona, Spain. April 23-26.

Progress 10/01/09 to 09/30/10

Outputs
OUTPUTS: Organized Jordan Water Week 2010, Amman, Jordan, March 2010 Organized US-France binational research meeting, Purdue University, West Lafayette, IN May 2010 Organized Mexico meetings - Purdue University, April 2010; Mexico City, October 2010 PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Water management engineers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The modeling technology is changing the way researchers characterize and model porous media and has been adopted by one of Europe's largest agronomic modeling projects: SEAMLESS (System for Environmental and Agricultural Modeling: Linking European Science and Society). This work on pedostructure is recognized as pioneering in the emerging field of hydropedology (which integrates hydrology, soil physics, and pedology). A new white paper was adopted using this approach at the US-French bilateral conference at Purdue in May of 2010.

Publications

• Braudeau, E., R.H. Mohtar, N. El Ghezal, M. Crayol, M. Salahat, and P. Martin. 2009. A multi-scale "soil-water structure" model based on the pedostructure concept. Hydrol. Earth Syst. Sci. Discuss., 6, 1111-1163, 2009 www.hydrol-earth-syst-sci-discuss.net/6/1111/2009/ doi:10.5194/hessd-6-1111-2009
• Braudeau, E., and R.H. Mohtar. 2009. Modeling the Soil System: Bridging the Gap Between Pedology and Soil-Water Physics. Global Planetary Change (special issue for Land Use). doi: 10.1016/j.gloplacha.2008.12.002
• Abou Najm, M., R.H. Mohtar, J. Weiss, and E. Braudeau. 2009. Assessing internal stress evolution in unsaturated soils. Water Resources Research. VOL. 45, W00C11, doi:10.1029/2007WR006484, 2009. Featured in Ecology, Environment and Conservation. Atlanta: Feb 27, 2009. P. 273.
• Ouessar, M., A. Bruggeman, F. Abdelli, R.H. Mohtar, D. Gabriels, and W. Cornelis. 2009. Modelling water-harvesting systems in the arid south of Tunisia using SWAT. Hydrology and Earth System Sciences, 13:2003-2021, 2009. www.hydrol-earth-syst-sci.net/13/2003/2009/
• Mohtar, R.H., E. Braudeau, and H. Belhouchette, eds. 2010. Multi-scale water and land-use modeling in support for better decision making.
• Dare, A., R.H. Mohtar, J. Lumkes, Jr., P.K. Imbrie, A. Ciftci, and S. Tanner. 2009. Global Design Team: Concept & Projects. 12th Annual Colloquium on International Engineering Education. Ames, IA. October 22-25.
• Mohtar, R.H. and M.E. Rahbeh. 2009. Finite Element Modeling of Multi-Phase Contaminant Transport in Porous Media. In State-of-the-Art in Application of Finite Element Numerical Solutions to Engineering Problems: A Session Honoring Pioneering Contributions of Professor Kamyar Haghighi of Purdue University. 2009 ASABE Annual International Meeting, Reno, Nevada. June 21-24.
• Abou Najm, M. R., J. D. Jabro, W. M. Iversen, R. H. Mohtar, and R. G. Evans. 2010. New method for the characterization of three-dimensional preferential flow paths in the field, Water Resour. Res., 46, W02503, doi:10.1029/2009WR008594.
• Abou Najm, M.R., R.H. Mohtar, K.A. Cherkauer, and B.F. French. 2010. Effect of Integrating Hydrologic Scaling Concepts on Students' Learning and Decision Making Experiences. Advances in Engineering Education 2(1) Spring.
• Silliman, S., R.H. Mohtar, K.G. Paterson, and W.P. Ball. 2010. Engineering Academic Programs for Hydrophilanthropy: Commonalities and Challenges. Journal of Contemporary Water Research and Education August 145:5-29.
• Shirmohammadi, A., A. Madani, R.H. Mohtar, and H. Montas. 2009. State-of-the-Art in Application of Finite Element Numerical Solutions to Engineering Problems: A Session Honoring Pioneering Contributions of Professor Kamyar Haghighi of Purdue University. 2009 ASABE Annual International Meeting, Reno, Nevada. June 21-24.
• Mohtar, R.H., M. Salahat, M. Abou Najm, J. Mallory, and E. Braudeau. 2009. Hydropedology-Based Approach for Scaling Hydrological Processes. International Conference: Water, Environment, Energy, and Society. National Institute of Hydrology, Roorkee, India. January 12-19.
• Braudeau, E., R.H. Mohtar, and P. Martin. 2009. SoilWater2 Model Component. In System for Environmental and Agricultural Modelling: Linking European Science and Society.

Progress 10/01/08 to 09/30/09

Outputs
OUTPUTS: Hydrologic scaling and transfer across scales is one of the major challenges facing the soil and water discipline. This project leads the development of a unique new modeling paradigm that allows improved field water management through greater accuracy of prediction of contaminant transport and transfer, and incorporation of overburden pressure in the representative element structural volume. The modeling tools being developed in this project characterize soil water medium using shrinkage, swelling, water potential properties and stress-strain relationships within the medium. It also provides a systematic procedure for upscaling the local soil water medium (pedostructure) processes to the pedon, field, and watershed scales. An integrated laboratory - field and modeling activities to help charactertize and model the muilti-scale system is underway. Laboratory measurements of stresses, water potential, volume change, conductivity are being conducted to characterize soil water dynamics. These measurements are collected to help develop crossing scales relationships and to evaluate the modeling tools being developed. In addition to the impact on the scientific community and the nuerous technical publications completed, this work was introduced to classroom and found very effective in addressing issues of scale to users (students). PARTICIPANTS: Participants: Erik Braudeau, IRD, France Darrel Schulze, Purdue University Jason Weiss, Purdue University Gary Heathman, USDA ARS Jay Jabro, USDA ARS TARGET AUDIENCES: 1) Scientists in the soil and water conservation engineering areas. 2) Decision makers in charge of environmental regulation. PROJECT MODIFICATIONS: Project Modifications: An integrated laboratory - field and modeling activities to help characterize and model the multi-scale system - is underway. Laboratory measurements of stresses, water potential, volume change, and conductivity are being continued to characterize soil water dynamics. These measurements are being used to conceptualize a soil water medium representation. Field measurements are collected to help develop crossing scales relationships and to evaluate the modeling tools being developed.

Impacts
The modeling technology is changing the way researchers characterize and model porous media and has been adopted by one of Europe's largest agronomic modeling projects: SEAMLESS (System for Environmental and Agricultural Modeling: Linking European Science and Society). This workon pedostructure is recognized as pioneering in the emerging field of hydropedology (which integrates hydrology, soil physics, and pedology).

Publications

• Mohtar, R.H. and M.E. Rahbeh. 2009. Finite Element Modeling of Multi-Phase Contaminant Transport in Porous Media. In State-of-the-Art in Application of Finite Element Numerical Solutions to Engineering Problems: A Session Honoring Pioneering Contributions of Professor Kamyar Haghighi of Purdue University. 2009 ASABE Annual International Meeting, Reno, Nevada. June 21-24.
• Shirmohammadi, A., A. Madani, R.H. Mohtar, and H. Montas. 2009. State-of-the-Art in Application of Finite Element Numerical Solutions to Engineering Problems: A Session Honoring Pioneering Contributions of Professor Kamyar Haghighi of Purdue University. 2009 ASABE Annual International Meeting, Reno, Nevada. June 21-24.
• Ouessar, M., A. Bruggeman, F. Abdelli, and R.H. Mohtar. 2008. Adaptation and Evaluation of SWAT Model for Application in an Arid Watershed in southeast Tunisia. Eds. Bruggeman, A., M. Ouessar, and R. H. Mohtar. ICARDA, Alleppo Syria. iv + 173 pp.
• Bruggeman, A., M. Ouessar, and R. H. Mohtar (eds). 2008. Watershed Management in Dry Areas: Challenges and Opportunities. ICARDA, Alleppo Syria. iv + 173 pp.
• Mohtar, R.H., M. Salahat, M. Abou Najm, J. Mallory, and E. Braudeau. 2009. Hydropedology-Based Approach for Scaling Hydrological Processes. International Conference: Water, Environment, Energy, and Society. National Institute of Hydrology, Roorkee, India. January 12-19.
• Braudeau, E., R.H. Mohtar, and P. Martin. 2009. SoilWater2 Model Component. In System for Environmental and Agricultural Modelling: Linking European Science and Society.

Progress 10/01/07 to 09/30/08

Outputs
OUTPUTS: Hydrologic scaling and transfer across scales is one of the major challenges facing the soil and water discipline. This project leads the development of a unique new modeling paradigm that allows improved field water management through greater accuracy of prediction of contaminant transport and transfer, and incorporation of over burden pressure in the representative element structural volume. The modeling tools being develop in this project characterizes soil water medium using shrinkage, swelling, water potential properties and stress-strain relationships within the medium. It also provides a systematic procedure for up-scaling the local soil water medium (pedostructure ) processes to the pedon, field, and watershed scales. An integrated laboratory - field and modeling activities to help characterize and model the multi-scale system is underway. Laboratory measurements of stresses, water potential, volume change, conductivity are being conducted to characterize soil water dynamics. These measurements are being used to conceptualize a soil water medium representation. Field measurements are collected to help develop crossing scales relationships and to evaluate the modeling tools being developed. In addition to the impact on the scientific community and the numerous technical publication completed, this work was introduced to classroom and found very effective in addressing issues of scale to users (students). PARTICIPANTS: Erik Braudeau, IRD, France Darrel Schulze, Purdue University Jason Weiss, Purdue University Gary Heathman, USDA ARS Jay Jabro, USDA ARS TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: An integrated laboratory - field and modeling activities to help characterize and model the multi-scale system is underway. Laboratory measurements of stresses, water potential, volume change, conductivity are being conducted to characterize soil water dynamics. These measurements are being used to conceptualize a soil water medium representation. Field measurements are collected to help develop crossing scales relationships and to evaluate the modeling tools being developed.

Impacts
The modeling technology is changing the way researchers characterize and model porous media and has been adopted by one of Europe's largest agronomic modeling projects : SEAMLESS (System for Environmental and Agricultural Modeling: Linking European Science and Society). This work on pedostructure is recognized as pioneering in the emerging field of hydropedology (which integrates hydrology, soil physics and pedology).

Publications

• Abou Najm, M., C. Mohtar, R.H. Mohtar, and R. Drnevich. 2008. Improving TDR Measurements through Accounting for Soil Structural Properties. ASABE Technical Session IET-19 Advances in Instrumentation and Control. June 30. Providence, RI.
• The list below includes refereed publications, journal articles. 2008.
• Marcato, C., R.H. Mohtar, J.-C. Revel, P. Pouech, and M. Guiresse. 2008. Impact on Organic Matter Quality During Pig Slurry Anaerobic Treatment. Environmental Science & Technology. In press.
• Belhouchette, H., E. Braudeau, R. H. Mohtar, M. Donatelli, and Wery. 2008. Integrating Spatial Soil Organization Data with a Regional Agricultural Management Simulation Model: a Case Study in Northern Tunisia. Transactions of the ASABE. 51(3): 1099-1109.
• Ouessar, M., A. Bruggeman, F. Abdelli, R.H. Mohtar, D. Gabriels, and W. Cornelis. 2008. Modelling water-harvesting systems in the arid south of Tunisia using SWAT. Hydrology and Earth System Sciences Discussions. In press.
• Braudeau, E., and R.H. Mohtar. 2008. Modeling the Soil System: Bridging the Gap Between Pedology and Soil-Water Physics. Global Planetary Change (special issue for Land Use). In press.
• Abou Najm, M., R.H. Mohtar, J. Weiss, and E. Braudeau. 2008. Assessing internal stress evolution in unsaturated soils. Water Resources Research. In press.
• The list below includes manuscripts in review. 2008.
• Braudeau, E., R.H. Mohtar, N. El Ghezal, M. Crayol, M. Salahat, P. Clouvel, E. Jallas, and P. Martin. 2008. Modeling and Characterizing Soil Hydrostructural Properties. Journal of Hydrologic Engineering. In Review.
• Anmala, J., and R.H. Mohtar. Fourier Stability Analysis of Two-Dimensional Finite Element Schemes for Shallow Equations. 2008. International Journal for Numerical Methods in Fluids.
• Miller, P., B.A. Engel, R.H. Mohtar, A. McFarland, J. Mitchel, P. Kalita, and K. Karthikeyan. 2008. A combinatorial methodology for estimating total and propagated mass load distribution error from water quality data. ASCE J. Hydrologic Engineering.
• Rahbeh, M., and R.H. Mohtar. 2008. Analysis of Mass Transfer Processes during Air Sparging. Journal of Contaminant Hydrology.
• The list below includes books/book chapters. 2008.
• Martin, P., E. Braudeau, R.H. Mohtar, and P. Clouvel. 2008. SoilWater2 Component. SEAMLESS Project Book. M. Donatelli, ed. In press.
• Mohtar, R.H., T. Zhai, J-Y Choi, and B. Engel. 2008. Web-based GIS Hydrologic Modeling for Siting Water Harvesting Reservoir. In: Watershed Management in Dry Areas, Challenges and Opportunities. Eds. Bruggeman, A., M. Ouessar, and R. H. Mohtar. ICARDA Press. Alleppo Syria.
• Bruggeman, A., M. Ouessar, and R. H. Mohtar. 2008. Watershed Management in Dry Areas, Challenges and Opportunities. ICARDA Press. Alleppo Syria.
• The list below includes publications available on microfiche. 2008.
• Mohtar, R.H., K. Cherkauer, B. French, and M. Abou Najm. 2008. Effect of Large Scale Multilmedia Hydrologic Modeling Tools on Student Learning and Decision Making. NACTA/SERD Conference. Utah State University.
• Braudeau, E., V. Auffray, R.H. Mohtar, and E. Jallas. 2008. Integrated Ecological Modeling Using Pedostructure Concept. Presentation of both computer models, Kamel and KamelSoil. EUROSOIL 2008. August 25-29.
• Braudeau, E., and R.H. Mohtar. 2008. Bridging the gap between pedology, soil physics and hydrology. Academie des Sciences de Paris.
• Salahat, M., R.H. Mohtar, E. Braudeau, M. Abou Najm, and P. Martin. 2008. Kamel(R): A new Soil Water Modeling Paradigm. First International Conference on Hydropedology. University Park, PA. July 28-31.
• Abou Najm, M., R.H. Mohtar, J. Weiss, and E. Braudeau. 2008. The Restrained Ring Method: A New Tool for soil characterization. ASABE Technical Session SW-5 Vadose Zone Characterization and Modeling. July 2. Providence, RI.
• Abou Najm, M., R.H. Mohtar, and J. Jabro. 2008. Characterizing Soil Cracking at the Field Scale. ASABE Technical Session SW-5 Vadose Zone Characterization and Modeling. July 2. Providence, RI.
• Ouessar, M., A. Bruggeman, F. Abdelli, R.H. Mohtar, D. Gabriels, and W.M. Cornelis. 2008. Use of SWAT for assessing the effect of Lane Use Changes in southern Tunisia. EGU General Assembly, Vienna, Austria. April 13-18.
• Mohtar, R.H., I. Hua, and L. Nies. 2008. Ecological Engineering Science in Undergraduate Engineering Education. EGU General Assembly, Vienna, Austria. April 13-18.
• Abou Najm, M.R., R.H. Mohtar, J. Jabro, D. Schulze, J. Weiss, Bill Iversen, K. Cherkauer, and E. Braudeau. 2008. Towards a Better Understanding of the Cracking Behavior of Soils. EGU General Assembly, Vienna, Austria. April 13-18.
• Mohtar, R.H., E. Braudeau, M. Abou Najm, M. Salahat and P. Martin. 2008. Kamel. EGU General Assembly, Vienna, Austria. April 13-18.

Progress 10/01/06 to 09/30/07

Outputs
OUTPUTS: The model used as the starting point of this phase of the research is based on 2-DSTREAM (Jaber and Mohtar, 2002a, 2000b, 2003). The model solves the two-dimensional kinematic wave model using one of the three finite element method schemes: consistent, lumped and upwind. A clear advantage of the finite element method over other methods is in its flexibility in representing an irregular shaped watershed. Among other advantages, the finite element method also provides users with the ease of handling boundary and initial conditions. The model input data requirements are: nodal coordinates, nodal slopes, nodal slope aspects, nodal Manning's roughness values in addition to elemental excess rainfall. These data sets are available from topographic, soil, land use and land cover maps available at USDA, USGS and other agencies. The output of the model includes flow depth at any point in time and space, in addition to the flow rate in both the x and y direction. This allows for the generation of hydrographs, wave profiles at times and nodes of the user choice at any location within the watershed. PARTICIPANTS: Bernard A. Engel, ABE, Purdue University Jane R. Frankenberger, ABE, Purdue University Mark Nearing, ARS, USDA Vijay Singh, Texas A&M University Eric Braudeau, IRD, France TARGET AUDIENCES: Hydrologists and watershed managers

Impacts
Sustainability involves using our resources efficiently, maintaining or improving environmental quality, as well as maintaining or improving the productivity, economic opportunities, and health of all people. Environmental and natural resource conservation engineering programs have evaluated the environmental impacts of land use and water management; innovative soil and groundwater remediation technologies have been developed; numerical methods to biological engineering systems have been developed; and soil water medium at the pedon, field, and watershed scales have been characterized. International sustainable water management programs that deal with population growth and water shortage conditions in arid climates, have been designed and evaluated. IMPACT: A comprehensive effort developed the GRAzing SImulation Model (GRASIM) to examine water, nutrient, and carbon flows in pasture environments. GRASIM is the first comprehensive grazing model, and is currently used by several U.S. and international institutions to optimize production while minimizing environmental impacts. A new soil and water characterization and flow model (Kamel) will allow for improved field water management, more accurate predictions of contaminant transport and transfer, incorporation of overburden pressure, and will provide a systematic procedure for up-scaling the pedostructure processes to the pedon, field, and watershed scales.

Publications

• Braudeau, E., M. Salahat, R.H. Mohtar, and A. Abou Najm. 2007. Soil water potential: measurement and modeling of the tensiometric curve. Geophysical Research Abstracts Vol. 9, 11275. European Geosciences Union. SRef-ID: 1607-7962/gra/EGU2007-A-11275.
• Braudeau, E., R.H. Mohtar, M. Ronin, M. Abou Najm, M. Salahat, C. Day, J. Mallory, and A. Conklin. 2007. KamelSoil: A model for soil characterization from basic soil textural properties. ASABE Annual Meeting. June 17-20. Minneapolis, MN. ASAE Paper #07-2214
• Salahat, M., R.H. Mohtar, E. Braudeau, and M. Abou Najm. 2007. Development and Evaluation of Functional Soil Mapping Unit Using Pedostructure Hierarchy Concept. ASABE Annual Meeting. June 17-20. Minneapolis, MN. ASAE Paper #07-2220.
• Abou Najm, M., R.H. Mohtar, J. Weiss, and E. Braudeau. 2007. Assessing soil residual stresses and their impact on cracking behavior. ASABE Annual Meeting. June 17-20. Minneapolis, MN. ASABE Paper #07-8007.
• Abou Najm, M., R.H. Mohtar, K.A. Cherkauer, and B. French. 2007. Integrating Large-Scale Hydrologic Modeling Into Student Learning and Decision Making. ASABE Annual Meeting. June 17-20. Minneapolis, MN. ASABE Paper #07-2214.
• Mohtar, R.H. and E. Braudeau. 2006. Modeling Soil Water Movement in Pedostructure. ASABE paper #06-2228.
• Martin, A. R.H. Mohtar, B.A. Engel, B. French, and G. Rochon. 2006. Assessment of the Century Model Web Interface in Undergraduate Education to Improve Decision-making and Learning. ASABE paper #06-8002.
• Rahbeh, M.E. and R.H. Mohtar. 2006. Modeling Multiphase Contaminant Transport in Porous Media Using First-Order Mass Transfer Kinetics. Transactions of the ASABE 49(6): 1935-1945.
• Miller, P.S., R.H. Mohtar, and B.A. Engel. 2007. Analysis of common water quality monitoring schemes and their effects upon mass load calculation. Transactions of the ASAE 50(3):817.829.
• Rochon, G.L., L.F. Nies, C.T. Jafvert, J.A. Stuart, R.H. Mohtar, J. Quansah and A. Martin. 2006. Education in sustainable production in US universities. Clean Techn Environ Policy. DOI 10.1007/s10098-005-0027-2.
• Braudeau, E., and R.H. Mohtar. 2006. Modeling the Swelling Curve for Packed Soil Aggregates Using the Pedostructure Concept. SSSAJ. 70:494-502. DOI: 10.2136/sssaj2004.0211; PII.
• Rahbeh, M.E. and R.H. Mohtar. 2006. Application of Multiphase Transport Models to Field Remediation by Air Sparging and Soil Vapor Extraction. Journal of Hazardous Materials. doi:10.1016/j.jhazmat.2006.09.098.
• Rahbeh, M. and R.H. Mohtar. 2006. Modeling Multiphase Contaminant Transport in Porous Media using First Order Mass Transfer Kinetics. Transactions of the ASABE. 2006:49(6): 1935-1945.
• Braudeau, E. and R.H. Mohtar. 2006. Bridging the Gap Between Pedology and Soil Physics. In 20 Years of Nonlinear Dynamics in Geosciences. Eds. Jim Elsner and Tasos Tsonis. Springer.
• Bruggeman, A., M. Ouessar, and R. H. Mohtar. 2006. Watershed Management in Dry Areas, Challenges and Opportunities. ICARDA Press. Alleppo Syria.
• Salahat, M., R.H. Mohtar, and E. Braudeau. 2006. Delineating Field Scale Functional Soil Mapping Units. ASABE Paper #06-2221.

Progress 10/01/05 to 09/30/06

Outputs
Sustainability involves using our resources efficiently, maintaining or improving environmental quality, as well as maintaining or improving the productivity, economic opportunities, and health of all people. Environmental and natural resource conservation engineering programs have evaluated the environmental impacts of land use and water management; innovative soil and groundwater remediation technologies have been developed; numerical methods to biological engineering systems have been developed; and soil water medium at the pedon, field, and watershed scales have been characterized. International sustainable water management programs that deal with population growth and water shortage conditions in arid climates, have been designed and evaluated.

Impacts
A comprehensive effort developed the GRAzing SImulation Model (GRASIM) to examine water, nutrient, and carbon flows in pasture environments. GRASIM is the first comprehensive grazing model, and is currently used by several U.S. and international institutions to optimize production while minimizing environmental impacts. A new soil and water characterization and flow model (Kamel) will allow for improved field water management, more accurate predictions of contaminant transport and transfer, incorporation of overburden pressure, and will provide a systematic procedure for up-scaling the pedostructure processes to the pedon, field, and watershed scales.

Publications

• Mohtar*, R.H. T. Zhai*, J-Y Choi, and B.A. Engel. 2006. Web-based GIS Hydrologic Modeling for Siting Water Harvesting Reservoir. In: Watershed management in dry areas, challenges and opportunities. Eds. Bruggeman, A., M. Ouessar, and R.H. Mohtar. ICARDA Press. Alleppo Syria.
• Braudeau*, E., R.H. Mohtar*, and N. Chahinian*. 2005. Estimating soil shrinkage parameters. In: Y. Pachepsky and W.J. Rawls (eds.) Development of pedotransfer functions in soil hydrology. Elsevier, Amsterdam, The Netherlands. Pp. 225-240. DOI 10.1016/S0166-2481(04)30013-9.
• Braudeau*, E. and R.H. Mohtar*. 2004. Soil water functions in pedostructure. In Encyclopedia of Water Science. Marcel Dekker, Stewart and Howell, eds. DOI:10.1081/E-EWS 120021076
• Bruggeman*, A., M. Ouessar*, and R. Mohtar*. Year. 2006. Watershed management in dry areas, challenges and opportunities. ICARDA Press. Alleppo Syria. 150 pages.

Progress 10/01/04 to 09/30/05

Outputs
The first objective of this project is to develop and validate enhanced numerical methods based watershed scale models to facilitate hydrologic/water quality analysis towards this objective. The model to be used as the starting point of this research for the first objective is based on 2-DSTREAM which solves the two-dimensional kinematic wave model using one of the three finite element method schemes. In order to investigate the effect of spatial and temporal manipulation on the solution accuracy, a sensitivity analysis will be performed for the watershed slope, the Mannings roughness coefficient and the excess rainfall rate for various spatial and temporal levels of discritization and watershed scenarios. A reference run will be conducted on a fine mesh in which a value for slope and Mannings roughness coefficient will be calculated for each node and a value of excess rainfall rate will be calculated for each element. Using ArcView GIS, these values of slope, roughness and excess rainfall will be aggregated to various spatial and temporal scales. This will be done by generating new meshes and averaging the values of the slope, roughness and excess rainfall in each new element. Simulations will be conducted to evaluate the effect of slope aggregation, the effect of Mannings roughness coefficient aggregation and the excess rainfall rate aggregation on the outflow rate. Due to the large cost and time involved in field measurements, smart error estimators based on limited field measurements and spatial geostatistics characterization offers a tool to represent this variability. The second objective is to develop and validate integrated bio-physical models to assist with silvopastoral, water quality, and hydrologic system management at field scales. Towards this goal, a comprehensive computer simulation model will be developed building on the GRASIM model to explicitly describe forage and tree growth, animal grazing, and interaction with environment in terms of soil water and nutrient cycling. These dynamic interactions can be simulated throughout the growing season to determine their impacts on system productivity and economic performance. An experimental silvopastoral system, located at the Martell Experimental Forest, approximately eight miles west of Purdue University will be used in validation of the enhanced model.

Impacts
The impact of the grazing simulation model (GRASIM), and the hydrologic model 2DSTREAM air sparging model (SPARG), will continue to be major as long as economic and environmental issues are of public concern in the application and development of new numerical methodologies for agricultural and biological engineering applications. My leadership in conducting workshops and facilitating technical interactions for using and developing numerical methods through ASABE is helping to make this technology available both to agricultural and commercial users in the state of Indiana as well as the Midwest region.

Publications

• Braudeau, E., M. Sene, and R.H. Mohtar. 2004. Hydrostructural Characteristics of two African tropical soils. European Journal of Soil Science. DOI:10.111/J.1365-2389.2004.00679.X
• Braudeau, E., J.P. Frangi, and R.H. Mohtar. 2004. Characterizing non-rigid aggregated soil-water medium using its shrinkage curve. Soil Science Society of America Journal. 68(359-370)
• Braudeau, E., and R.H. Mohtar. 2004. Water potential in non-rigid unsaturated soil-water medium. Water Resources Research. (40)W05108, doi:10.1029/2004WR03119
• Zhai, T., R.H. Mohtar, H. Karsten, and M. Carlassare. 2004. Modeling growth and competition of a multi-species pasture system. Transactions of the ASAE. 47(2):617-627
• Zhai, T., R.H. Mohtar, F. El-Awar, W. Jabre, and J.J. Volenec. 2004. Parameter Estimation for Process-Based Crop Growth Models. Transactions of the ASAE: 47(6):2109-2119.
• Jaber, F., and R.H. Mohtar. 2003. Stability and accuracy of two-dimensional kinematic wave overland flow modeling. Advances in Water Resources. 26(2003)1189-1998.
• Benner, M.L. R.H. MOhtar and L.S. Lee. 2002. Factors affecting air sparging remediation systems using field date and numerical simulations. Journal of Hazardous Materials. B95(2002)305-329.
• Jaber, F.H. and R.H. Mohtar. 2002. Dynamic Time Step for One-Dimensional Overland Flow Kinematic Wave Solution. Journal of Hydrologic Engineering. ASCE 7(1):3-11.
• Jaber, F.H. and R.H. Mohtar. 2002. Stability and accuracy of finite element schemes for the one-dimensional kinematic wave solution. Advances in Water Resources. 25(2002)427-438.