| Full text | |
| Author(s): |
de Souza Ferreira, Murilo
[1]
;
de Campos Jordao, Carlos Eduardo Kolb Maynardes Araujo
[2]
;
de Souza Inacio Goncalves, Julio Cesar
[3]
;
Dodds, Walter Kennedy
[4]
;
Cunha, Davi Gasparini Fernandes
[1]
Total Authors: 5
|
| Affiliation: | [1] Univ Sao Paulo, Dept Engn Hidraul & Saneamento, Escola Engn Sao Carlos, Ave Trabalhador Sao Carlense 400, BR-13566590 Sao Carlos, SP - Brazil
[2] Embrapa Pecuaria Sudeste, Empresa Brasileira Pesquisa Agr, Rodovia Washington Luiz, Km 234, BR-13560970 Sao Carlos, SP - Brazil
[3] Univ Fed Triangulo Mineiro, Dept Engn Ambiental, Ave Dr Randolfo Borges Jr 1250, BR-38064200 Uberaba, MG - Brazil
[4] Kansas State Univ, Div Biol, 116 Ackert Hall, Manhattan, KS 66506 - USA
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | WATER AIR AND SOIL POLLUTION; v. 231, n. 2 JAN 25 2020. |
| Web of Science Citations: | 0 |
| Abstract | |
The reaeration coefficient (K-a20) is one of the main indicators of dissolved O-2 movement to and from aquatic systems via the atmosphere. Direct gas tracer measurements, physical models, and models of O-2 dynamics have been used for K-a20 estimation, especially in temperate aquatic ecosystems, with fewer examples in their tropical counterparts. Here we investigate a less commonly employed soluble floating probe (SFP) method, based on the dissolution rate of a soluble solid (V-S20) as an auxiliary variable for K-a20 estimation. Our objectives were to test the SFP method for estimating K-a20, validate such estimates through the traditional gas tracer method, and develop empirical models for K-a20 prediction using V-S20 and additional physical variables. Five reaches (with lengths from 20 to 250 m) of four tropical headwater streams were selected, and their main physical, hydrological, and hydraulic variables were measured in eight sampling periods. The gas tracer (using NaCl and SF6 tracers) and the SFP (spherical format made with oxalic acid dihydrate) methods were carried out in each reach. The K-a20 values ranged from 16.94 to 373.79 days(- 1) and the V-S20 ranged from 0.079 to 0.778 mm min(- 1). We observed a significant linear relationship between K-a20 and V-S20. The best model (R-2 = 0.78) combined the variables depth, Froude number, and V-S20. Our study highlighted that models developed for temperate aquatic systems can underestimate K-a20 in tropical streams, bringing uncertainties for modeling metabolic rates, self-depuration capacity, or any other processes that depend on reaeration. (AU) | |
| FAPESP's process: | 16/14176-1 - Macronutrient retention in Cerrado streams (SP) and its relationships with aquatic metabolism along gradients of environmental conditions: an ecosystem services' approach |
| Grantee: | Davi Gasparini Fernandes Cunha |
| Support Opportunities: | Regular Research Grants |