Monitoring methods of dunefield susceptible to human activities in the Nísia Floresta area, eastern coast of the State of Rio Grande do Norte, Brazil

V. D. Araujo, Y. A. Reyes-Pérez, R. C. Freire, D. S. Gauw, D. A. S. Santos, P. Fracasso, A. M. Souza, A. P. M. R. Pelosi, V. C. Córdoba, F. P. Lima-Filho
2006 Wit Transactions on Ecology and The Environment   unpublished
The coastal area of northeastern Brazil shows a wide range of dunefields, which were formed during the Holocene and Pleistocene periods. In the eastern coast of the Rio Grande do Norte State (RN), these aeolian provinces are characterized by older (stabilized by vegetation) and young (without vegetation) dunefields. They cover a large coastal zone, which forms important aquifers that supply water to several coastal cities, including Natal, the capital of the state. This coastal area is also
more » ... al area is also characterized by the tourism industry, which is considered one of the most important financial resources and means of employment generation. Despite this importance, no study has been carried out concerning the impact of tourism activities in this area. Because of this, the aim of this work is to present a monitoring method of the coastal dunefields in the town of Nísia Floresta, Brazil, including the periodical identification of internal geometries of dunes with GPR profiling, and external geometries of dunes using a Geodesic GPS. The study area is characterized by SE-NW-trending dunefields. They are composed of blowouts, blowout dunes, and interdune areas, which have been modified by human occupation and off-road vehicle driving. The data permits the analysis of depositional and erosional controls and relates it to the reference of the Dunas Park, a conservation area near the town of Nísia Floresta. Environmental Problems in Coastal Regions VI 389 permitted the generation of digital elevation models (DEM). The Real Time Kinematics GPS (RTK) was used for high-precision positioning in real time. The results can present subdecimal precision [10] . This technique requires the presence of a reference station and a mobile station. The reference station involving two segments. One segment is represented by (i) a transmitter radio and its respective antenna, and (ii) a "legant" antenna and a "legacy" receptor. A mobile station, called a rover, is in fact a GPS with a Hyper system, allowing the communication with a base and a collector for data storage. The attributes x, y, and z can be collected at each point or in a continued mode. At Búzios Beach, the rover was fixed to the quadricycle, making the process of data survey faster than usual, fig. 3a . On the other hand, at Dunas Park, where vehicle traffic is prohibited, control points were acquired with a rover transported manually, fig. 3b . The software GOCAD was used for three-dimensional visualization of the information collected in the field. www.witpress.com, ISSN 1743-3541 (on-line)
doi:10.2495/cenv060371 fatcat:a2fivlklk5hu5bqrfrnngsbuku