Abstract
The hydrological and meteorological characteristics of the watersheds of the inner Gulf of Honduras in the western Caribbean, including runoff, sediment load and yield, and the effects of the El Niño–La Niña cycle, are examined using available data. The inner Gulf of Honduras, bordered by the second-longest coral reef complex in the world, the MesoAmerican Barrier Reef, receives runoff from the watersheds of 12 rivers with a total simulated annual discharge of 1232 m3 s−1. Expanding agricultural and industrial activities contribute to the influx of sediments, nutrients, and pollutants from these rivers, leading to increased threats to the health of the reef ecosystem. The watersheds of the Moho, Sarstún, and Polochic-Dulce Rivers receive more than 4000 mm of rainfall annually and are major sources of discharge and sediment load, along with the Motagua and Ulua, farther to the east. The drainage basins are characterized by runoff ratios of 0.30–0.55 and simulated sediment yields as high as 869 t km−2 yr−1. The results from two different sediment load/yield models agree to within ±2.3% at the 95% confidence level. Sediment load estimates increase by as much as 5 times on model comparisons of present land use to increased land use. Time series of precipitation for the inner Gulf of Honduras exhibit bimodal distribution with maxima in May–June and in September–October. Analysis of long-term climatic data reveals only a weak but measurable correlation with El Niño–La Niña. The Southern Oscillation index explains on average 7%–15% of the precipitation and temperature variability for the inner Gulf of Honduras.
Corresponding author address: Dr. Björn Kjerfve, Marine Science Program, University of South Carolina, Columbia, SC 29208. Email: bjorn@msci.sc.edu
