Influence of extended drought on water quality in tropical reservoirs in a semiarid region
AimDrought periods often occur in Brazilian semiarid region and are supposed to induce water quality degradation by changes in physical, chemical and biological properties of freshwater ecosystems. Reservoirs in this region are used as drinking-water supplies and are exposed to wide volume fluctuati...
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| Format: | Article |
| Language: | English |
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Associação Brasileira de Limnologia
2015-03-01
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| Series: | Acta Limnologica Brasiliensia |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2179-975X2015000100003&lng=en&tlng=en |
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| author | Gustavo Girão Braga Vanessa Becker José Neuciano Pinheiro de Oliveira Jurandir Rodrigues de Mendonça Junior Anderson Felipe de Medeiros Bezerra Laíssa Macêdo Torres Ângela Marília Freitas Galvão Arthur Mattos |
| author_facet | Gustavo Girão Braga Vanessa Becker José Neuciano Pinheiro de Oliveira Jurandir Rodrigues de Mendonça Junior Anderson Felipe de Medeiros Bezerra Laíssa Macêdo Torres Ângela Marília Freitas Galvão Arthur Mattos |
| author_sort | Gustavo Girão Braga |
| collection | DOAJ |
| description | AimDrought periods often occur in Brazilian semiarid region and are supposed to induce water quality degradation by changes in physical, chemical and biological properties of freshwater ecosystems. Reservoirs in this region are used as drinking-water supplies and are exposed to wide volume fluctuations during drought periods due to lack of precipitation and high evaporation rates. This study aimed to identify patterns on water quality of two reservoirs during a long drought period. It was expected that more arid and shallower conditions would favor algal growth by enhancing nutrient availability, causing a decrease on water quality.MethodsThe study was based on monthly sampling over 20 months (May 2011 to December 2012) at two tropical reservoirs on Brazilian semiarid region. Precipitation and volume data were obtained from environmental agencies. Transparency was measured on field using a Secchi disk and conductivity, nutrients, suspended solids and chlorophyll-a were analyzed on laboratory. Temporal changes in all environmental variables were analyzed in each reservoir using two-way cluster analysis and also principal component analysis (PCA).ResultsThe volume of both reservoirs decreased considerably over the study because of low or shortage of precipitation. It was possible to detect two opposite patterns of chlorophyll-a in each reservoir throughout the drought season: in the first one phytoplankton growth was favored, while in the second one chlorophyll-a decreased by high inorganic turbidity. Both reservoirs tended to increase their turbidity and conductivity during the drought period due to shallow conditions, which probably contributed to sediment resuspension.ConclusionsWater level reduction during the extended drought period, contributed for water quality degradation due to high algal biomass and also high turbidity found during drought period. Local factors, as the nature of suspended solids, play an important role on predicting water quality. |
| first_indexed | 2024-12-10T11:24:05Z |
| format | Article |
| id | doaj.art-4065fd48b8a449b9903c15c76f53b5a5 |
| institution | Directory Open Access Journal |
| issn | 2179-975X |
| language | English |
| last_indexed | 2024-12-10T11:24:05Z |
| publishDate | 2015-03-01 |
| publisher | Associação Brasileira de Limnologia |
| record_format | Article |
| series | Acta Limnologica Brasiliensia |
| spelling | doaj.art-4065fd48b8a449b9903c15c76f53b5a52022-12-22T01:50:48ZengAssociação Brasileira de LimnologiaActa Limnologica Brasiliensia2179-975X2015-03-01271152310.1590/S2179-975X2214S2179-975X2015000100003Influence of extended drought on water quality in tropical reservoirs in a semiarid regionGustavo Girão BragaVanessa BeckerJosé Neuciano Pinheiro de OliveiraJurandir Rodrigues de Mendonça JuniorAnderson Felipe de Medeiros BezerraLaíssa Macêdo TorresÂngela Marília Freitas GalvãoArthur MattosAimDrought periods often occur in Brazilian semiarid region and are supposed to induce water quality degradation by changes in physical, chemical and biological properties of freshwater ecosystems. Reservoirs in this region are used as drinking-water supplies and are exposed to wide volume fluctuations during drought periods due to lack of precipitation and high evaporation rates. This study aimed to identify patterns on water quality of two reservoirs during a long drought period. It was expected that more arid and shallower conditions would favor algal growth by enhancing nutrient availability, causing a decrease on water quality.MethodsThe study was based on monthly sampling over 20 months (May 2011 to December 2012) at two tropical reservoirs on Brazilian semiarid region. Precipitation and volume data were obtained from environmental agencies. Transparency was measured on field using a Secchi disk and conductivity, nutrients, suspended solids and chlorophyll-a were analyzed on laboratory. Temporal changes in all environmental variables were analyzed in each reservoir using two-way cluster analysis and also principal component analysis (PCA).ResultsThe volume of both reservoirs decreased considerably over the study because of low or shortage of precipitation. It was possible to detect two opposite patterns of chlorophyll-a in each reservoir throughout the drought season: in the first one phytoplankton growth was favored, while in the second one chlorophyll-a decreased by high inorganic turbidity. Both reservoirs tended to increase their turbidity and conductivity during the drought period due to shallow conditions, which probably contributed to sediment resuspension.ConclusionsWater level reduction during the extended drought period, contributed for water quality degradation due to high algal biomass and also high turbidity found during drought period. Local factors, as the nature of suspended solids, play an important role on predicting water quality.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2179-975X2015000100003&lng=en&tlng=eneutrofizaçãomanancialvolumeclorofilasólidos suspensos |
| spellingShingle | Gustavo Girão Braga Vanessa Becker José Neuciano Pinheiro de Oliveira Jurandir Rodrigues de Mendonça Junior Anderson Felipe de Medeiros Bezerra Laíssa Macêdo Torres Ângela Marília Freitas Galvão Arthur Mattos Influence of extended drought on water quality in tropical reservoirs in a semiarid region Acta Limnologica Brasiliensia eutrofização manancial volume clorofila sólidos suspensos |
| title | Influence of extended drought on water quality in tropical reservoirs in a semiarid region |
| title_full | Influence of extended drought on water quality in tropical reservoirs in a semiarid region |
| title_fullStr | Influence of extended drought on water quality in tropical reservoirs in a semiarid region |
| title_full_unstemmed | Influence of extended drought on water quality in tropical reservoirs in a semiarid region |
| title_short | Influence of extended drought on water quality in tropical reservoirs in a semiarid region |
| title_sort | influence of extended drought on water quality in tropical reservoirs in a semiarid region |
| topic | eutrofização manancial volume clorofila sólidos suspensos |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2179-975X2015000100003&lng=en&tlng=en |
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