Bathymetric study of the Ayarza Lagoon

Abstract

Lakes and lagoons perform various vital functions for ecosystems and the socioeconomic development of the populations surrounding them. Ayarza Lagoon is located 108 kilometers from the capital city, between the municipalities of Casillas and San Rafael Las Flores, in the department of Santa Rosa, Guatemala. This lagoon is considered a relatively small lentic body, which is why there is no information that allows defining its characteristics, making it impossible to determine its current condition and define future. This research sought to define the depth and cross-sections of the lagoon through its bathymetry. The lagoon was determined to be 5.78 kilometers long, 3.73 kilometers wide, and with a perimeter of 20.00 kilometers, occupying an area of ​​13.80 square kilometers during the dry season (February-March) in 2015. The methodology used consisted of field procedures such as topographic surveying using a GPS, as well as the drawing of a grid across its entire surface to take depth measurements with an echo sounder. The information collected was used to develop software to determine the contour lines and sections of the lagoon, revealing that there are areas in the center of the lagoon that are deeper than 400 meters. This information provides a baseline for future research work to determine the eutrophic conditions of the lagoon and/or for actions to be taken, such as dredging.