Optimal Management of a Coastal Aquifer with Interacting Resources
Invasive kiawe, which has the ability to capture groundwater from underlying aquifers, noticeably affects economically optimal drawdown patterns of the aquifer over long time horizons
Local and global changes continue to influence interactions between groundwater and terrestrial systems. Increasing demand due to population and income growth, changing precipitation patterns, and land cover conversion all affect the water balance of a given watershed, and thus affect both the quantity and quality of freshwater entering and leaving the ground. Recent groundwater economics research has begun to incorporate climate change projections and expected demand growth patterns, but few studies have focused on jointly managing land cover and groundwater withdrawals. We modify a simple coastal aquifer model to allow for the possibility that an interdependent terrestrial resource can also affect water balance in the region. In an application to the Kona Coast, we find that the invasive kiawe (Prosopis pallida), which has the ability to capture groundwater from underlying aquifers, noticeably affects economically optimal drawdown patterns of the aquifer over long time horizons. Because the objective is to maximize the net present value of water, the integrated management model necessarily examines the tradeoff between groundwater pumping and kiawe removal and minimizes their combined cost over time. We find that the timing of optimal kiawe removal is especially sensitive to the rate of water demand growth; when demand is increasing at an annual rate of 3% or greater, kiawe should be removed immediately over the entire range of removal costs under consideration.
Supported by: NSF EPSCoR Grant No. EPS-0903833
REPORTS AND PRODUCTS
LINKS AND UHERO NEWS
- Coming Soon