4. Conclusion
The study aimed to test the efficacy of remote sensing and geophysical
techniques to quantify and understand the water cycle in a savanna
wetland of Brazil. ERT and the digital aerial photogrammetry from RGB
sensors aboard UAV are non-destructive techniques for assessing water
cycling in wetlands and can be used to identify, quantify and promote
the protection of water resources. The studied wetland is a depressed
area in a well-drained lateritic environment in the Cerrado biome,
surrounded by agricultural areas. The wetland acts as a natural seasonal
rainwater reservoir, storing up to 416.996,3 m³ of water on the land
surface during the rainy months. The distinct internal compartments that
characterize the wetland morphology present distinct water storage.
Furthermore, water is retained in soil porosity, feeding the aquifer by
vertical flow and permeable and impermeable layers in soil and rock
characterize the complex hydrology of this environment. Surface water
and aquifer are connected in the center of the wetland through direct
vertical flow, whereas the subsurface heterogeneity interrupts the flow
direction, driving the water laterally and expanding the flooded area.
Remotely sensed VHR images allied with geophysical techniques allowed
complete surface and subsurface imaging and offered visual tools that
significantly contribute to understanding hydrodynamics of the wetland.
Further studies will be focused on assessing water use conflict between
wetland water storage and agricultural consumption.