  Groundwater is one of the most vital of all common pool resources throughout
the world. More than half of groundwater is used to grow crops. This research
models groundwater depletion patterns within a multi-agent system framework.
Irrigators are modeled as agents in the multi-agent system. The irrigation
strategies adopted by the agents are investigated using game theory. A set of
five irrigators, growing three crops: corn, sorghum and wheat, have been
considered in this study. To allow groundwater flow, these agents are assumed
to be located in adjoining farm lands. Irrigators are modeled selfish agents
that strategize their irrigation patterns in order to maximize their own
utilities, i.e. the difference between the total revenue obtained from crop
sales and the costs incurred, including groundwater extraction costs. Due to
groundwater flow, and have no incentive to conserve groundwater. This leads to
unsustainable depletion of the resource under Nash equilibrium, when no
irrigator can increase its utility by unilaterally changing its strategy. All
parameters in this research are representative of Kansas. Recorded
environmental and economic data of the region, along with the DSSAT software,
have been used to obtain these futuristic projections. One of the emergent
phenomena of the simulations is the adoption of crop rotation patterns by the
irrigators to conserve groundwater. The irrigators grow corn, which is a more
profitable yet water intensive crop in one year, and in the next, conserve
water by growing sorghum instead. Another emergent outcome of this research is
the viability of LEMAs. When the irrigators are subject to LEMA-level limits on
groundwater use, there is a slight increase in the aggregate utility of the
LEMA.
