Development of digital bathymetry maps for Lakes Azuei and Enriquillo using sonar and remote sensing techniques

Abstract

This article presents an improved algorithm for optimization and development of a digital bathymetric model (DBM) for Lake Azuei (LA) (Haiti) and Lake Enriquillo (LE) (Dominican Republic) using the ANUDEM method. Both sonar data and contour lines of the lakes' layout extracted using Landsat imagery were compiled for bathymetry development. We show that the performance of the ANUDEM method was strongly dependent on the density and irregularity of the spatial distribution of the data. Changing the resolution of the output grids and deriving auxiliary topographically corrected contours improved the ANUDEM performance and minimized the systematic errors of the method. Statistical analysis showed no significant difference between measured and interpolated depths, characterized by a root mean square error of less than 0.71 m (LE) and 0.96 m (LA), and a median difference of −0.009 m (LE) and 0.012 m (LA) on average. The shape reliability analysis revealed a relationship between accuracy and the depth and slope values, increasing in the center of the lakes where they are deep and the slope is gentle.

Development of Predictive Models for Water Budget Simulations of Closed-Basin Lakes: Case Studies of Lakes Azuei and Enriquillo on the Island of Hispaniola

“…The valley on the south of the island is called the Cul de Sac depression on the Haitian side and the Enriquillo plain on the Dominican Republic side [26]. LE is located in the lowest part of the valley, about 33.2 m below mean sea level (MSL), covering an area of 325.3 km 2 (November 2017), and having two deep sections in the north and south with shallow edges on the west and east [27]. About five kilometers to the west of LE lies LA at about 23.0 m above MSL, with a surface area of 134.75 km 2 (November 2017) and steep banks around its shoreline [27].…”

“…LE is located in the lowest part of the valley, about 33.2 m below mean sea level (MSL), covering an area of 325.3 km 2 (November 2017), and having two deep sections in the north and south with shallow edges on the west and east [27]. About five kilometers to the west of LE lies LA at about 23.0 m above MSL, with a surface area of 134.75 km 2 (November 2017) and steep banks around its shoreline [27]. Both lakes are saline in nature, with LE's salinity level being higher (34 ppm) than LA's (7-9 ppm, reducing to <5 ppm in the vicinity of subsurface springs).…”

“…Other datasets that supported the work were the lakes' monthly volume and surface area time series from 1972 to 2017 [8,27,28]. These datasets were derived from Landsat Imagery analysis and two field campaigns conducted in 2013 by CUERG for bathymetry surveys of the lakes [48].…”

Lake Volume Data Analyses: A Deep Look into the Shrinking and Expansion Patterns of Lakes Azuei and Enriquillo, Hispaniola

“…Of all archived images 252 and 297 images for LE and LA, respectively [13], proved suitable for constructing the lakes' surface area time series. Subsequent derivation of the lakes' observational VTS was achieved through combining the bathymetry of LE and LA and the lake surface area values; for more on this the reader is referred to [12][13][14][15][16]. Figure 2 presents the observational VTS' for both lakes for the period of 1972-2017.…”