Science Inventory

QUANTIFYING SEDIMENT CONTRIBUTIONS TO THE GUÁNICA BAY PUERTO RICO

Citation:

Yuan, Y., E. Mbonimpa, W. Hu, W. Fisher, AND A. Casper. QUANTIFYING SEDIMENT CONTRIBUTIONS TO THE GUÁNICA BAY PUERTO RICO. Presented at 2012 AWRA Annual Water Resources Conference, Jacksonville, FL, November 12 - 15, 2012.

Impact/Purpose:

In watersheds feeding Guánica Bay (southwestern Puerto Rico), increased soil erosion and sediment loading to streams and rivers has raised concern that sediment has reduced reservoir capacity, polluted the Bay, and adversely affected coral reef condition in the coastal zone.

Description:

The island of Puerto Rico faces considerable challenges regarding sustainable land use and effects of land use on adjacent freshwater and marine ecosystem services. In watersheds feeding Guánica Bay (southwestern Puerto Rico), increased soil erosion and sediment loading to streams and rivers has raised concern that sediment has reduced reservoir capacity, polluted the Bay, and adversely affected coral reef condition in the coastal zone. The success of potential management options will depend partly on knowing where the sediment originates. However the hydrology in the region is very complex. Guánica Bay is fed almost exclusively by Rio Loco, but waters in Rio Loco come from as many as six different watersheds, a consequence of five reservoirs constructed in the early 1950s that are linked by tunnels. In addition, water from the lowest of these reservoirs, Lago Loco, is distributed by gravity far to the west (Lajas Valley) for agricultural irrigation and returned by drainage canal to Rio Loco before it empties into Guánica Bay. Increased sediment loading may result from increased agricultural production in the region since the 1950’s, especially the growth of sun-grown coffee plantations along mountain ridges. This region has high soil erosion and soil loss which directly affects the four upstream reservoirs. The objectives of this study are to: 1) identify sediment sources; 2) quantify sediment contributions from upstream watersheds to Rio Loco; 3) to explore alternative strategies to reduce soil erosion and sediment loading to the reservoirs, Guánica Bay and the coastal zone. To achieve the above objectives and build a model for this complex interwoven watershed system, we applied the Soil and Water Assessment Tool (SWAT) and Gridded Surface Subsurface Hydrology Analysis (GSSHA). The SWAT was applied to the ridge watersheds, which are dominated by coffee plantations, to estimate soil erosion and sediment loadings to the r

URLs/Downloads:

YUAN ORD-000812 FINAL POSTER..PDF   (PDF,NA pp, 336 KB,  about PDF)

YUAN ORD-000812 ABSTRACT QUANTIFYING SEDIMENT CONTRIBUTIONS.PDF   (PDF,NA pp, 32.32 KB,  about PDF)

Record Details:

Record Type: DOCUMENT (PRESENTATION/POSTER)
Product Published Date: 11/15/2012
Record Last Revised: 01/06/2016
OMB Category: Other
Record ID: 243372

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL EXPOSURE RESEARCH LABORATORY

ENVIRONMENTAL SCIENCES DIVISION

LANDSCAPE ECOLOGY BRANCH