Researcher · Nelson Institute SAGE · UW–Madison

Agricultural water, groundwater sustainability, and land-use transitions.

I develop data-driven models and decision-support tools to evaluate agricultural adaptation to water scarcity, with emphasis on groundwater-dependent regions, irrigation technology, crop choice, and land-use transitions.

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Affiliation: Nelson Institute SAGE, UW–Madison Focus: U.S. High Plains Aquifer Contact: karthik.ramaswamy@wisc.edu
Portrait of Karthik Ramaswamy
UW–Madison Agricultural Economics Groundwater Sustainability Geospatial Modeling Decision-support Tools

Research Profile

My research focuses on how agricultural systems adapt to water scarcity, groundwater depletion, and changing economic conditions. I combine agricultural economics, geospatial analysis, hydro-economic modeling, and optimization to evaluate irrigation transitions, crop choice, land-use change, and decision-support strategies.

Groundwater Sustainability

Studying aquifer depletion, irrigation capacity decline, and agricultural transition pathways in groundwater-dependent regions.

Irrigation Economics

Evaluating irrigation investments, pumping costs, crop profitability, and water-use decisions under changing hydrologic and economic conditions.

Geospatial Modeling

Integrating GIS, remote sensing, county-level crop data, climate variables, soil data, and groundwater datasets for regional agricultural systems analysis.

Decision-support Tools

Developing applied tools using Excel/VBA, Python, ArcGIS, and GAMS to support irrigation planning and agricultural adaptation analysis.

Research in Maps

Irrigated agriculture across the United States, and county-scale results from my hydro-economic modeling of the High Plains Aquifer: where groundwater is declining fastest, when irrigated maize is likely to give way to dryland systems, and where perennial bioenergy crops could take its place.

Map of the conterminous United States showing irrigated land as a share of county area in 2015, with the High Plains Aquifer outlined. Irrigation concentrates over the aquifer, in California's Central Valley, the Snake River Plain, the Mississippi Delta, and southern Florida.
Where the United States irrigates Irrigated land as a share of county area in 2015, from USGS county water-use estimates, with the High Plains Aquifer outlined. The aquifer underlies the largest contiguous block of irrigated farmland in the country, and it is the region my research focuses on.
Map of the High Plains Aquifer showing annual groundwater level change, with the strongest declines in southwest Kansas, the Oklahoma and Texas panhandles, and the Texas High Plains
Annual groundwater level change Mean rate of water-level change from 2009 to 2024, from USGS monitoring. Declines concentrate in the central and southern High Plains, where saturated thickness is thin.
Map of modeled years until counties in the High Plains Aquifer transition from irrigated maize to dryland production
Time to dryland transition Modeled years until irrigated maize becomes economically or hydrologically infeasible in each county. Cross-hatched counties see no transition within the 30-year simulation.
Map of modeled cumulative bioenergy feedstock biomass production by county across the High Plains Aquifer over 30 years
Bioenergy feedstock potential Cumulative 30-year biomass output from all modeled feedstocks on land leaving irrigated maize, highest in central Nebraska and eastern Colorado.

National map: K. Ramaswamy, from USGS Estimated Use of Water in the United States, County-Level Data for 2015 and the USGS High Plains Aquifer boundary (public domain). High Plains figures from Ramaswamy, Uludere-Aragon, and Lark (2026), Agricultural Water Management 334, 110675 (open access, CC BY). Click a map to view it at full size.

Featured Projects

Current and recent projects focus on irrigation transitions, bioenergy crop systems, groundwater conservation, and agricultural decision-support tools.

Map of modeled 30-year change in groundwater storage across the High Plains Aquifer
Groundwater · Optimization

High Plains Aquifer Irrigation Transition Model

A hydro-economic model evaluating how irrigated agriculture may transition under groundwater depletion, irrigation capacity constraints, crop profitability, and reinvestment decisions.

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Map of the opportunity cost of switching from irrigated maize to perennial switchgrass by county across the High Plains Aquifer
Bioenergy · Land Use

Bioenergy Crops and Groundwater Conservation

Research evaluating whether perennial bioenergy crops can support transitions from water-intensive irrigated agriculture while contributing to conservation and resilience goals.

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Diagram of a center-pivot irrigation circle inside a quarter-section field, with the High Plains Aquifer outlined on an inset map of the United States
Decision Tool · Irrigation

Irrigation System Upgrade Decision Tool

An Excel/VBA and GIS-based decision-support tool for evaluating irrigation system upgrades using climate, crop yield, soil, slope, energy, and investment data.

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GIS · Data Systems

Agricultural Water and Land-use Data Integration

Spatial data workflows linking crop production, irrigation status, climate, groundwater, soil, and economic variables for agricultural water systems analysis.

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Selected Publications

Selected manuscripts, tools, and applied research products related to groundwater sustainability, irrigation transitions, bioenergy crop systems, and agricultural decision support.

2026

Opportunities for Bioenergy Crops to Support Transitions from Irrigated Agriculture and Conserve the U.S. High Plains Aquifer

Ramaswamy, K., Uludere-Aragon, N., and Lark, T. J.

Agricultural Water Management, 334, 110675.

Evaluates how bioenergy crops and dryland transitions may support groundwater conservation and long-term agricultural adaptation in the U.S. High Plains Aquifer region.

DOI PDF Data
Under Review

Well Capacity per Hectare Equipped for Irrigation Indicates Modeled Maize-to-Sorghum Transitions under Ogallala Aquifer Depletion

Ramaswamy, K., Stoecker, A. L., Warren, J. G., Jones, R. D., Taghvaeian, S., and Vitale, J. D.

Agricultural Water Management. Under review.

A 60-year farm–aquifer optimization for the Oklahoma High Plains estimates when maize gives way to grain sorghum as well capacity declines, and identifies well capacity per installed hectare as a candidate indicator of crop transitions.

Manuscript coming soon
2024

Economic Strategies to Synergistically Produce Bioenergy and Optimize Aquifer Life in the U.S. High Plains

Ramaswamy, K., Lark, T. J., and Uludere-Aragon, N.

AAEA Conference Proceeding.

Pilot study to evaluate the most economically viable non-irrigated agricultural systems in the U.S. High Plains Aquifer region.

DOI
2021

Issues Facing the Californian Fruit Sector

Asci, S., and Ramaswamy, K.

Choices, 36(2).

Economic impacts of labor, water, trade, and regulatory issues in fruit farming in California.

Article
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Methods, Data, and Technical Expertise

I use quantitative, spatial, and computational methods to connect agricultural data, water-resource constraints, economic decisions, and regional land-use outcomes.

Hydro-economic modeling Optimization GIS and remote sensing ArcGIS Python GAMS R MODFLOW Google Earth Engine Excel/VBA Crop-water analysis Groundwater datasets Net present value analysis

Interested in research collaboration or related work?

I welcome inquiries related to agricultural water management, groundwater sustainability, irrigation economics, land-use transitions, and decision-support modeling.

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