Quadros, Clécio José Lopes de 
occur Besides its role as a protection system against the invasion of the sea during storms, this area has 
ecological importance for being as an important rest stop point and feeding for migratory birds. 
h the 
is act 
3. THE LOCAL BEACH RIDGE SYSTEM'S FUNCTIONING 
areas 
ed on The morphological structure of the area had its origin from the interaction Land-Sea-Atmosphere that 
occurs at this site, mainly from the movement of sediments brought by the littoral drift coming from the South. 
Part of this drift, when passing by the region, meets a hydraulic barrier formed by the mouth of the Bay of 
Paranagua, these currents loose energy, causing the deposition of these sediments. By this way, it is basically 
formed by the deposition of beach ridges, built from this recent material coming from the littoral drifts. 
The system works mainly due to the associations that occur between the morphological structure, 
yf the hydrological regime, and atmospheric regime. The swamps and swampy regions have their expansion and 
. This retraction determined by the hydrological system, which is regulated by the rain regime and tides dynamic. This 
ing a acts on the mode of direct intrusion and contact of the sea water with the underground water. 
es, as This means that the functioning of this environment in centered on the entrance and exit of water and 
w an sediments from this system. During the rainy period, that occurs during summer, the functioning of the 
interactions shows to be more intense, what causes several changes on the physical and chemical structures of 
this environment. 
4. METHODOLOGY 
  
The study was done in three parts: 1) field data sampling; 2) post-processing of GPS data; and 3) 
processing and analysis at GIS. 
ur The field data were sampled with a DGPS Reliance Super C/A (Geodesic) Ashtech, firstly 
concentrating on the mapping of the contour and of the draining system of the area, walking around. After this, 
it was defined the punctual sampling mesh that consisted of 48 profiles perpendicularly to the coastline (Figure 
2). And at each sampled point the characteristics of soil moisture level and morphological form were wrote 
down. The geographical co-ordinates and altitude were collected by DGPS, being the receiver (base) situated in 
a Portobräs geodesic landmark. The altitude values are not related to the sea level, they correspond to the 
altitude relative to the geodesic landmark. The GPS sample taxa was of 1 second with acquisition time to the 
point of 1 minute. The distance between the points of the same profile was determined by the variation of 
ground characteristics, what means that, if there was a dune it was taken a point on the base of the dune, one at 
the top, and another on the posterior base. 
In order to remove inaccuracies from the field data due to the random degradation (S4) a post- 
processing differential was made. The processing used was the decimeter processing that use carrier phase of 
the L1 satellite signal. After this, the points that showed an error bigger than 0,5m were discharged at the 
  
— longitudes and latitudes, and bigger than 0,2m at altitude. A total of 933 points were used. 
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 1201