Spatial and Temporal Hydrochemical Variation of a Third Order River Network in a Quasi Pristine Coastal Watershed, at Southern Bahia, Brazil

Anais da Academia Brasileira de Ciências

Elly R.s. De Souza¹  Francisco C.f. De Paula¹ 

关键词: Rivers ecology;    dissolved nutrients;    biological reserve;    wetlands;    Ecologia de rios;    nutrientes dissolvidos;    reserva biológica;    áreas alagadas;   

DOI  :  10.1590/0001-3765201364111

来源: SciELO

【 摘 要 】

ABSTRACTRio da Serra watershed presents well preserved fragments of rain forest at the headwaters and small farms at middle and final stretches. These features allowed the study of fluvial hydrochemistry, under quasi pristine conditions. Sampling stations were established in order to represent the basin, and visited during dry, intermediate and wet periods. Obtained results are: temperature (22.1 – 28.6 °C); electric conductivity (34 – 52 µS-cm); dissolved oxygen (35 – 110%); pH (3.8 – 7.7); total suspended solids (1.1 – 20 mg-L); chlorophyll (1.0 – 9.2 µg-L); total N (74 – 580 µmol-L); particulate N (60 – 550 µmol-L); N-NO3 (0.1 – 9.3 µmol-L); dissolved organic N (4 -70 µmol-L); total phosphorous (5.3 – 47 µmol-L); particulate P (4.4 – 59 µmol-L); P-PO4 (0.1 – 0.7 µmol-L); dissolved organic P (0.01 – 2.0 µmol-L); silicate (30 -90 µmol-L); fecal coliforms (80 – 700 CFU-100mL). In seasonal terms dissolved oxygen, electric conductivity, nitrate and silicate concentrations were higher during the dry, whereas TSS was higher during the wet period. Seasonal differences of dissolved oxygen, temperature, pH and nitrate were also detected near wetlands areas. Along the basin results showed a distinction between headwaters and other sections, revealing a control of fluvial hydrochemistry by the preserved area, mostly for the dissolved organic N and P species and phosphate.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License