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Decision scenario analysis for addressing sediment accumulation in Lago Lucchetti, Puerto Rico
Citation:
Fisher, W. AND J. Bousquin. Decision scenario analysis for addressing sediment accumulation in Lago Lucchetti, Puerto Rico. A Community on Ecosystem Services, Washington, DC, December 08 - 12, 2014.
Impact/Purpose:
Presentation for ACES conference
Description:
A Bayesian belief network (BBN) was used to characterize the effects of sediment accumulation on water storage capacity of a reservoir (Lago Lucchetti) in southwest Puerto Rico and the potential of different management options to increase reservoir life expectancy. Water and sediment enter the Lago Lucchetti from the watershed and from a tunnel linked to three upstream reservoirs. The BBN was initialized using the original construction volume of the reservoir (1952) and two bathymetric surveys completed in 1986 and 2000, which show that water storage capacity has declined dramatically because of sediment trapping. As the reservoir fills in, the ability to trap sediment declines so greater amounts of incoming sediment are moving downstream to sensitive ecosystems. Sensitivity analysis demonstrated most of the sediment delivery to Lago Lucchetti was from sediment erosion in the Lucchetti watershed with only a minor contribution from upstream reservoirs (8%). A management option to dredge the reservoir would add significantly to reservoir life expectancy; conversion of sun-grown to shade-grown cultivation in the Lucchetti watershed would decrease sediment delivery by about 11%. A BBN approach is very flexible, allowing consideration of multiple decision alternatives, alone and in combination, and accommodating both qualitative and quantitative information.