Problem and Project Goal• Cost-effective adaptation to increased water

demand due to population growth, increased irrigation, urbanization, and economic development is contingent upon sufficiently understanding the complexity characterizing land use and water availability dynamics. The southeastern U.S. has an opportunity to adapt to these changes and address concerns over the allocation and conservation of water before water resources become fully allocated and opportunities for cost-effective adaptation to these changing conditions evaporate.

• Climate change could exacerbate this stress, with increasingly uncertain rainfall patterns and the amplified risk of extreme weather events, including both longer and deeper droughts and higher rainfall events.

• The long term goal of this project is to assist agricultural producers, policymakers, and local communities throughout the southeastern U.S. adapt to a new reality of water scarcity by efficiently allocating water across competing uses and by adopting water-conserving practices and technologies.

Project Study Region

Research and Outreach Components

The research component of the project integrates a physical, water balance model with an economic input-output model linking water use to economic activity. This integration enables the identification of areas and conditions over which water scarcity will impact economic activity and the economic value of water.

Water Budgets/Water Use Inventories – collect data on water use in representative agricultural enterprises.Hydrological Modeling – generate temporally-and spatially-explicit estimates of water availability and scarcity using the Variable Infiltration Capacity (VIC) water balance model under current and projected economic and environmental conditions.Economic Modeling – develop and apply a multi-sectoral model to determine the economic valuation of water among different use categories. Impacts of water availability on the agricultural sector and the economy are linked with the IMPLAN model.Outreach to Agricultural Producers – develop and disseminate a state-wide education program to inform Extension agents and agricultural producers about water use in agriculture and potential water-saving techniques for different agricultural enterprises.Youth and Adult Education – develop and disseminate a state-wide education program about water use for agricultural and domestic consumption and potential water-saving techniques for different agricultural and domestic enterprises across the state.

Acknowledgements: This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, Integrated Water Quality Competitive Grant No. #2014-08253. Contact: Christopher D. Clark, cdclark@utk.edu, (865)974-7471. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

Economic Modeling UpdateCurrent research efforts focus on the development and calibration of the TN Agricultural Production Model (TNAP). TNAP is a partial equilibrium model of Tennessee’s agricultural sector., structured on the California SWAP model1. TNAP operates at a sub-regional level delineated at the Hydrological Unit Code 4 (HUC-4) resolution. The row crops most likely to be irrigated in Tennessee are corn, soybeans, wheat, and cotton. Pastureland proxies the distribution of beef cattle operations.

HUC-4 Research RegionsTNAP is calibrated using Positive Mathematical Programming (PMP)1. For each activity, key data needs are: (1) per acre budgets (e.g., water, labor, land rent, chemicals) for each HUC region; (2) irrigation water availability; and (3) crop acreage supply elasticities.Enterprise budgets for dominant row crops have

been collected and integrated into the model and preliminary estimates of land supply elasticities developed. Next steps include:• Regionalizing crop budgets to provide

additional variation;• Determining irrigation water availability

through linkages with the Hydrological Modeling project component; and

• Integrating TNAP with IMPLAN to map agricultural sector impacts onto the regional economy.

1 Howitt, R.E., J. Medellín-Azuara, D. MacEwan, J.R. Lund, 2012. “Calibrating disaggregate economic models of agricultural production and water management,” Environmental Modeling & Software 38, 244-258

Potential Impacts & Expected Outcomes• Development of a versatile and robust method

useful in water budget studies for quantifying more accurately flow response based on vegetation cover and management practices;

• Enhanced understanding of land management impacts on water quantity in mixed agricultural watersheds;

• More sustainable water use and integrated surface/subsurface water management; and

• Increased awareness and understanding by agricultural producers, policy makers, and the general public of water use and availability, the allocation of water across competing uses, and the physical and economic impacts of land and water management policy and decision-making.

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Using Hydro-Economic Modeling to AnalyzeThe Allocation of Water In the Southeastern U.S.

C. Boyer, C.D. Clark, B.C. English, A. Fulcher, J. Hathaway, S. Hawkins, D.M. Lambert, L.H. Lambert, R.J. Menard, A.N. Papanicolaou, J. Schwartz, F.R. Walker, and C. Wilson

University of Tennessee, Knoxville