Morphology and morphometry of upland lakes over lateritic crust, Serra dos Carajás, southeastern Amazon region

Abstract

High-resolution satellite images, digital elevation models, bathymetric and sedimentological surveys coupled with statistical analysis were used to understand the physical environment and discuss their influence on water quality of the five upland lakes of Serra Sul dos Carajás, southeast Amazonia. The lakes have midaltitude ranges (elevation), very small (catchment) and shallow to very shallow (central basins). Based on the length, area and volume, Violão and TI (Três Irmãs)-3 lakes may present large vertical movements of the water due to wind action and weakly stratified waters. Trophic conditions based on depth and shore development (Ld) parameters must be used with caution, since Amendoim Lake is relatively deep, but it is oligotrophic to ultra-oligotrophic. Ld values suggest that the lakes are circular to subcircular and are likely formed by solution process, as also suggested by volume development. TI-2 Lake is only presenting convex central basin and has highest dynamic ratio (DR), thus it may have high sedimentation and erosion rates. Based on the relationship between studied parameters, morphometric index and DR likely influence temperature and dissolved oxygen of waters of TI-2 Lake due to its depth profile and wind-induced surface mixing. Nevertheless, water quality parameters are controlled by catchment characteristics of the lakes.