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Estudos geoquímicos relativamente à dinâmica de marés no estuário lagunar do rio Paraguaçu, Bahia, Brasil
| Content Provider | Semantic Scholar |
|---|---|
| Author | Barreto, Maria Angélica Silva |
| Copyright Year | 1993 |
| Abstract | The Paraguaçu River Lagoonal Estuary has been studied through five field observations in June, August, September and October 1992. Data have been collected in a fixed sampling station close to Frances Island, wich is located in the confluence of São Roque Chanel and Iguape Bay. Ali the analysed chemical parameters are related to local tidal dynamics. Temperature, Salinity, pH, Photic Index and stream velocity during inflow and outflow have also been monitored. Estuarine area hydrodynamics has shoon itself to be simetric, with inflow and outflow periods of six hours during neap tide nevertheless, this behaviour totaly changes during spring tide, possibly due to the influence of the Pedra do Cavalo Dam upriver, the low value to absent defluent discarges at the Dam allowing strong inflow from the Todos os Santos Bay inwards. The average heavy metal contents in bottom sediment are:Fe (0.21 %), Mn (266.7ppm), Zn (45.06ppm), Cu (40.65), Pb (51.38), Cd < 1.3) and Hg (0.202). The suspended load has been analysed in neap and spring tides. Average contents obtained in samples of suspended load collected during spring tide are: Fe (12,353.00 μg/g), Mn (164.00 μg/g), Zn (2,588.00 μg/g), Cu (< 2.03 μg/g), Pb (< 0.064 μg/g), Cd (< 13.75 μg/g). In neap tide the average contents obtained are: Fe (6,304.00 μg/g), Mn (188.00 μg/g), Zn (3,156.00 μg/g) and Hg (28.13 μg/g). Cu, Pb and Cd have not shown significant diferences fron. the results obtained in spring tide. In spring tide, Total Suspended Solids (TSS), contents averaged 26.20, Particulate Organic Matter (POM), average contents were 8.20 and Dissolved Organic Matter (DOM), average values are 219.00. During neap tide, TSS values around 27.76 have been obtained, POM values averaged 9.98, and DOM was found to be around 303.47. The metal contents obtained in bottom sediment seem to be related to the high volume of organic matter present as well as to anthropic factors. The observed diferent values of TSS, metal contents of Suspended sediment, particulate and dissolved Organic Matter (POM and DOM respectively), can be related to water inflow from the Todos os Santos Bay and to small defluent outflow from the Pedra do Cavalo Dam upstream during current inflow and outflow related to tidal dynamics. The high volume of Organic Matter both in the dissolved and particulate form reflects the intensive biological activity in the estuary. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://rigeo.cprm.gov.br/xmlui/bitstream/handle/doc/166/diss_Maria_Angelica.pdf?isAllowed=y&sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
