| dc.description.abstract |
As demand for freshwater resources rises, the importance of conservation and preservation
of ground-water resources become necessary, especially in coastal areas where large-scale
seawater intrusion is a risk. A hydrologic balance model that employs historic records
of precipitation, reference evapotranspiration estimates and future scenarios of withdrawal
rates is developed and used to forecast future groundwater levels. These model forecasts
are examined with a lens on the likelihood of 'dangerous' aquifer depletion (i.e.
a level that promotes sea water intrusion). This model uses the Central Coastal Plain
Capacity Use Area (CCPCUA) in eastern North Carolina as a case study. This case study
is selected here because of (i) ground water level data availability prior to and
post- imposed reductions of groundwater withdrawal rates (per capita), (ii) long-term
historic records of rainfall and estimated of reference evapotranspiration.
In this first-order analysis, a logical starting point in model development is to
assume that the network of regional aquifers within CCPCUA are perfectly connected
and equally accessible to pumping, the water level within the aquifer is uniform (but
not steady) and the aquifer hydraulic properties (such as specific yield) are uniform
in space. Under those idealized conditions, the hydrologic balance at this large-scale
can be treated as 'lumped' in space - so that water level redistribution in space
within the aquifer is highly efficient and only temporal dynamics of the water levels
in this lumped representation need to be accounted for. The impact of specific yield,
initial water depth, total population and its projection, per capita consumption (and
its future regulation), precipitation rates, reference evapotranspiration rates and
sea level rise on aquifer depletion are examined. The MP demonstrates how various
management scenarios intended to mitigate groundwater resource depletion can be examined
and cross-compared via model-assisted simulations, even in such idealized model-world.
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