The instantaneous transport of inorganic and organic material in a highly polluted tropical estuary

2013 ◽  
Vol 64 (6) ◽  
pp. 562 ◽  
Author(s):  
Carlos E. D. Noriega ◽  
Marilene Felipe Santiago ◽  
Patrícia Façanha ◽  
Maria da Glória Gonçalves da Silva Cunha ◽  
Rodolfo Araújo da Silva ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Coastal Area ◽  
Rainy Season ◽  
Phytoplankton Biomass ◽  
Dry Season ◽  
Tropical Estuary ◽  
Liquid Transport ◽  
Water Renewal ◽  
Rainy Period ◽  
Dissolved Inorganic Nutrients

The contribution of the estuarine channel of Recife harbour to the eutrophication of the Recife coastal area was evaluated by quantifying the instantaneous transport of salt, dissolved inorganic nutrients (PO4–, SiOH4, NO3–, NO2– and, NH4+), material in suspension, Chlorophyll-a, pico–nanoplankton and microplankton during the rainy (June 2007) and dry (November 2007) seasons. The results showed that all of the dissolved nitrogenated nutrients, the silicate and the material in suspension had higher concentrations during the rainy season, whereas the phosphate and Chlorophyll-a (both the total and the pico–nanoplankton and microplankton fractions) showed greater concentrations during the dry season. All of the materials considered were exported to the sea except for Chlorophyll-a (pico–nanoplankton and microplankton fractions) during the dry season, when these materials were imported into the area. The total liquid transport in the rainy season was three times higher than that found for the dry season. Silicate represented nearly 85% of the total exported material during the rainy period, whereas during the dry season, phosphate and silicate represented 79% of the total exported material. The stratification and circulation processes indicated a well mixed environment. The water-renewal rate was low, as demonstrated by the input of phytoplankton biomass during November. The area was characterised as eutrophic during the months investigated.

scholarly journals Thermal performance and concentration of gases in facilities for pigs in semiarid region from State of Paraiba - Brazil

2012 ◽  
Vol 32 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Dermeval A. Furtado ◽  
Daniele Amancio ◽  
José W. B. do Nascimento ◽  
Josivanda P. Gomes ◽  
Rafael C. Silva
Keyword(s):  
Carbon Monoxide ◽  
Thermal Comfort ◽  
Rainy Season ◽  
Dry Season ◽  
International Standards ◽  
Semiarid Region ◽  
Thermal Discomfort ◽  
Rainy Period ◽  
Globe Temperature ◽  
The Times

The study was conducted in a facility for pigs during the nursery and finishing in the town of 'Montadas', in the semiarid of the state of Paraiba, Brazil, in the rainy and dry season, aiming to evaluate the concentration of oxygen, methane, carbon monoxide and ammonia, and the bioclimatic indexes: ambient temperature (AT), relative humidity (RH) and the index of black globe temperature and humidity (IBGTH). These indexes differed significantly (P>0.05) between the periods and times. The AT in the rainy season was in the thermal comfort zone(TCZ) in most of the times in the nursery; for the finishing phase, thermal discomfort occurred; during the dry season, there was thermal comfort in the nursery phase; in the finishing phase the thermal discomfort occurred at all times. In the rainy season, the IBGTH was in TCZ; in the dry season, it was above the TCZ. The RH in the rainy period was in the TCZ; in the dry season, in most of the times, below the range of the TCZ. The concentration of gases showed no differences (P > 0.05) between periods and between the times, and the carbon monoxide, hydrogen sulfide and methane were below 1.0 ppm, and the ammonia showed a mean of 5.2 ppm. None of the analyzed gases exceeded the limits established by Brazilian and international standards for animals and workers.

scholarly journals Limnological characteristics of a reservoir in semiarid Northeastern Brazil subject to intensive tilapia farming (Orechromis niloticus Linnaeus, 1758)

2014 ◽  
Vol 26 (1) ◽  
pp. 47-59 ◽  
Author(s):  
Luis Artur Valões Bezerra ◽  
Walt Disney Paulino ◽  
Danielle Sequeira Garcez ◽  
Helena Becker ◽  
Jorge Iván Sánchez-Botero
Keyword(s):  
Chlorophyll A ◽  
Rainy Season ◽  
Dry Season ◽  
T Test ◽  
Northeastern Brazil ◽  
Human Consumption ◽  
Temperature Conductivity ◽  
Sampling Locations ◽  
Chemical Variability ◽  
Physical And Chemical

AIM: There is currently no consensus regarding the physical and chemical variability of tropical reservoirs. In semiarid Northeastern Brazil, reservoirs are among other things used for human consumption, industrial water supply and intensive fish farming, all of which can impact water quality. The objective of this study was to evaluate the physical and chemical variability of the water in Sítios Novos, a reservoir in semiarid Northeastern Brazil, comparing samples collected in areas of intensive tilapia (Oreochromis niloticus) farming to samples from areas not directly impacted by aquaculture, in both the dry and the rainy season. METHODS: Between October 2010 and July 2011, data were collected on temperature, conductivity, pH, turbidity, salinity, chlorophyll a, dissolved oxygen, oxygen demand, total phosphorus and total nitrogen levels in the water column using a multiparametric probe at four different sampling locations. Physical and chemical differences between the four locations were evaluated with the Kruskal-Wallis (KW) test and Dunn's post test, while the t test, followed by Welchʼs correction, was used to compare samples collected in different seasons. RESULTS: No influence of intensive aquaculture was detected when comparing sampling locations near fish farms (180C and 300C) to locations not directly impacted by aquaculture (LIMN1, near the dam, and LIMN2, near the debouch of the São Gonçalo river). However, the sampling locations differed significantly (p<0.05) with regard to conductivity, pH, turbidity and chlorophyll a levels. CONCLUSIONS: The physical and chemical variability was greater between seasons than between locations when the data were analyzed with the t test. That analysis showed significant differences for 22 of 40 comparisons between the 10 physical and chemical parameters in the two seasons at the four sampling locations. In conclusion, the physical and chemical variability registered for the Sítios Novos reservoir throughout the study period indicates morphometric, meteorological and hydrological heterogeneity, with emphasis on the differences between LIMN2 and the other three sampling locations and between the rainy season and the dry season. According to the calculated trophic status index, the reservoir is supereutrophic in the rainy season and supereutrophic to hypereutrophic in the dry season.

4. Archaeological Sites in the Galápagos Group

1956 ◽  
Vol 12 ◽  
pp. 13-21
Author(s):  
Thor Heyerdahl ◽  
Arne Skjölsvold
Keyword(s):  
Coastal Area ◽  
Rainy Season ◽  
Fine Sand ◽  
Dry Season ◽  
Archaeological Sites ◽  
Northwest Coast ◽  
James Bay ◽  
Local Conditions ◽  
Santiago Island

The principal site discovered by the expedition is on the northwest coast of James Bay, Santiago Island. The local conditions for primitive settlement are conspiciously better in this bay than in any other coastal area visited by the expedition in the Galápagos. To a passing craft James Bay opens up wide and impressive, well sheltered by forest-clad mountains sufficiently withdrawn from the coast to leave space for a large and level plateau lifted up like a terrace above the fine sand beaches of the bay (Fig. 3). In the rainy season glittering streams of water appear on the sides of a cone-shaped volcano (Sugar Loaf) and reveal from far out at sea the likely location of waterholes. Even in the dry season there are one or 2 dependable waterholes a couple of miles inland at the foot of this hill.

scholarly journals Efficiency of a constructed wetland for wastewaters treatment

2012 ◽  
Vol 24 (3) ◽  
pp. 255-265 ◽  
Author(s):  
Fernanda Travaini-Lima ◽  
Lúcia Helena Sipaúba-Tavares
Keyword(s):  
Chlorophyll A ◽  
Constructed Wetland ◽  
Rainy Season ◽  
Loading Rate ◽  
Dry Season ◽  
Rate Data ◽  
Inlet Channel ◽  
Concentration Data ◽  
Detention Time ◽  
Removal Efficiencies

AIM: The limnological characteristics of three different inlets water of the constructed wetland were compared in terms of concentration data and loading rate data and evaluated the removal efficiencies of nutrients, solids, BOD5, chlorophyll-a and thermotolerant coliforms (TC) by the treatment system; METHODS: The constructed wetland, measuring 82.8 m² and with detention time of 1 hour and 58 minutes in the rainy season and 2 hours and 42 minutes in the dry one, was provided with four species, Cyperus giganteus Vahl, Typha domingensis Pers., Pontederia cordata L. e Eichhornia crassipes (Mart.) Solms. The sampling sites evaluated in the dry (D) and rainy (R) seasons were: inlet water from aquaculture farm = IA; inlet channel of rainwater runoff = IR; inlet from UASB wastewater = IB; outlet wetland = OUT. The conductivity, pH, temperature, dissolved oxygen, alkalinity, BOD5, total soluble and dissolved solids, nitrogen, phosphorus, chlorophyll-a and TC were analyzed. Multivariate analyses, such as Cluster and Principal Components Analysis (PCA), were carried out to group sampling sites with similar limnological characteristics; RESULTS: In the PCA with the concentration data was retained 90.52% variability of data, correlating the inlet IB with high concentrations of conductivity, alkalinity, pH, TC, nutrients and solids. Regarding loading rate data, the PCA was retained 80.9% of the data's total variability and correlated the sampling sites IA D, IA R and OUT R with higher BOD5, chlorophyll-a, TDS, nitrate, nitrite, total-P, temperature, oxygen and water flow. The highest removal efficiencies rates occurred in the dry season, mainly in concentration, with 78% of ammonia, 95.5% of SRP, 94.9% of TSS and 99.9% of TC; CONCLUSIONS: The wetland was highly efficacious in the removal of nutrients, solids, BOD5, chlorophyll-a and TC, mainly during the dry season. The system restructuring to increase the detention time during the rainy season and a pre-treatment of UASB wastewater, can increase the retention of nutrients and solids by wetland.

scholarly journals Influence of river discharge on phytoplankton structure and nutrient concentrations in four tropical semiarid estuaries

2016 ◽  
Vol 64 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Hortência de Sousa Barroso ◽  
Helena Becker ◽  
Vânia Maria Maciel Melo
Keyword(s):  
Urban Areas ◽  
Rainy Season ◽  
River Discharge ◽  
Inorganic Nitrogen ◽  
Dry Season ◽  
Northeastern Brazil ◽  
Nutrient Concentrations ◽  
Freshwater Species ◽  
Rainy Period ◽  
Phytoplankton Structure

Abstract This study evaluated changes in phytoplankton and nutrients after an increase in river discharge in four estuaries of northeastern Brazil. Samples were taken during a markedly freshwater-deprived period (Nov/2010, dry season), and during a rainy season (May/2011). While two estuaries are located in urban areas (Ceará - CE and Cocó - CO), the others are markedly freshwater-deprived (Pacoti - PAC and Pirangi - PIR). Our findings indicate that increased freshwater had opposing effects on estuaries impacted by anthropogenic discharges (CO, CE and PIR) compared with the other, less impacted (PAC). In CO and CE, the freshwater flow during the rainy period had a nutrient diluting effect and controlled phytoplankton blooms. In PIR, only phosphorus and inorganic nitrogen decreased in the rainy season. In contrast, an increase of all nutrients was observed in PAC, and of TN in PIR, followed by an increase in phytoplankton biomass. In the rainy season, eutrophic freshwater species dominated in all the estuaries. In the dry season, blooms of Cryptomonas/Rhodomonas and Synechocystis aquatilis were, respectively, observed in CE and CO. Also in the dry season, PAC and PIR had a predominance of marine species under a condition of hypersalinity. Canonical correspondence analysis suggested the variation observed for salinity, silica, and TN are the main driver of phytoplankton structure.

scholarly journals Export of materials along a tidal river channel that links a coastal lagoon to the adjacent sea

2012 ◽  
Vol 60 (3) ◽  
pp. 311-322 ◽  
Author(s):  
Javier Aldeco Ramírez ◽  
Martha Signoret Poillon ◽  
María Adela Monreal Gómez ◽  
David Alberto Salas de León
Keyword(s):  
Chlorophyll A ◽  
Coastal Lagoon ◽  
Rainy Season ◽  
Dry Season ◽  
Tidal River ◽  
Tidal Channel ◽  
Effective Mechanism ◽  
Maximum Current ◽  
Tidal Velocity ◽  
The Mean

Intratidal variability and flux of salt, chlorophyll-a and suspended materials were evaluated in a shallow tropical tidal channel linking a coastal lagoon to the western Gulf of Mexico. Velocity, temperature and conductivity were used to calculate the fluxes. Data were recorded during three tidal velocity cycles (tvc) under extreme river discharge conditions. Chlorophyll-a and suspended materials were determined below the surface. In both seasons (dry and rainy), the flow was ebb-dominated and with longer duration than when in flood. Maximum current velocities were 0.30 m s-1 in May (dry season) and 0.60 m s-1 in September (rainy season). In the dry season the mean chlorophyll-a export was of 7.56 Kg over tvc while the import was of 3.32 Kg. In the rainy season mean export (47.3 Kg) was 6 times greater than the import (7.93 Kg over tvc). Phytoplankton was dominated by organisms of marine origin. The mean of exported, suspended materials in the rainy season (111.3 Kg) was 4.6 times greater (859 Kg) than that in the dry season (184.7 Kg over tvc). Tidal velocity asymmetry is an effective mechanism of exportation, introducing relatively warm and saltier water into the river through the tidal channel.

scholarly journals Soil microbiological properties and enzyme activity in agroforestry systems compared with monoculture, natural regeneration, and native Caatinga

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Divino Levi Miguel ◽  
Eliane Maria Ribeiro da Silva ◽  
Cristiane Figueira da Silva ◽  
Marcos Gervasio Pereira ◽  
Luiz Fernando Carvalho Leite
Keyword(s):  
Enzyme Activity ◽  
Mycorrhizal Fungi ◽  
Rainy Season ◽  
Farming Systems ◽  
Arbuscular Mycorrhizal ◽  
Agroforestry Systems ◽  
Dry Season ◽  
Rainy Period ◽  
One Year

The objective of this study was to evaluate the influence of agroforestry systems of different ages (AFS1: one-year old; AFS5: five-years old) on the biological attributes of soil; the following systems were used for comparison: a slash-and-burn (SBF) farming area, Caatinga which has been undergoing regeneration for 6 years (CaR6), and native Caatinga (NCa) in Brazil. Enzyme activity, abundance and composition of arbuscular mycorrhizal fungi (AMF), and production of glomalin-related soil proteins (GRSP) were evaluated at soil depths of 0–0.05 m. AMF species composition in the AFS was more similar to that in the NCa than in the SBF and CaR6 systems. In the rainy season, sporulation was most abundant in the AFS-1, CaR6, and SBF systems, whereas GRSP concentrations were highest in the AFS5 during the dry season. Acid phosphatase and arylsulfatase enzyme activity was lower in the AFS1 soils than in the NCa and SBF soils (rainy period), and levels of β-glucosidase and fluorescein diacetate hydrolysis in the AFS were equal to or higher than those in the NCa in the dry season but lower in the rainy season. AFS thus appear to promote the maintenance of soil biological quality, and may be more sustainable than SBF farming systems in the Brazilian Caatinga over the long term.

scholarly journals ÁP DỤNG MÔ HÌNH SWAN DỰ BÁO TRƯỜNG SÓNG VEN BỜ BIỂN HẢI PHÒNG

2019 ◽  
Vol 19 (1) ◽  
pp. 41-48
Author(s):  
Le Duc Cuong
Keyword(s):  
Wave Field ◽  
Wave Height ◽  
Coastal Area ◽  
Rainy Season ◽  
Dry Season ◽  
Maximum Height ◽  
Wave Direction ◽  
Swan Model ◽  
Dominant Wave ◽  
Near Shore

This paper presents some results of studying the SWAN model, and application of SWAN model to simulate wave field representative of the rainy season and dry season in the coastal area of Hai Phong. During the dry season, the dominant wave direction is in a range from 60o to 100o, maximum height of waves near shore is in a range from 1,0 m to 1,5 m with wavelength of about 2,0 m to 5,0 m, maximum height of waves offshore is in a range from 2,0 m to 2,5 m with wavelength of about 6,0 m to 16 m. During the rainy season, wave height near shore is in a range from 0,2 m to 0,6 m, and that offshore is in a range from 0,8 m to 1,4 m, maximum height of waves is about 3,4 m, predominant wave directions in this season are E, SE and S. In this scenario that predicts waves generated by storms, wave height offshore is in a range from 8,0 m to 10 m with wavelength of about 60 m, and that near shore is in a range from 2,0 m to 4,0 m with wavelength of about 10–20 m.

scholarly journals Surface-Water Quality of the Gulf of Papagayo, North Pacific, Costa Rica

Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2324
Author(s):  
Ana Y. Saravia-Arguedas ◽  
Hannia Vega-Bolaños ◽  
José Mauro Vargas-Hernández ◽  
Andrea Suárez-Serrano ◽  
Luis Sierra-Sierra ◽  
...  
Keyword(s):  
Water Quality ◽  
Costa Rica ◽  
Chlorophyll A ◽  
North Pacific ◽  
Rainy Season ◽  
Ammonium Phosphate ◽  
Dry Season ◽  
Northwestern Part ◽  
Starting Point

In recent years, the northwestern part of the North Pacific areas of Costa Rica has undergone rapid socioeconomic development. This situation, combined with the scarce available information about the water quality of the Gulf of Papagayo, became the starting point to carry out a study to investigate the spatiotemporal variations of physicochemical and biological parameters of surface waters. Seven samplings were collected during the dry season and the rainy season from October 2016 to February 2018. Water quality parameters such as: temperature, salinity, dissolved oxygen, and chlorophyll a of six analytes: nitrate, nitrite, ammonia, phosphate, silicate and biological oxygen demand were measured. The results showed that phosphate and ammonium levels were lower during the rainy season (<6 µg P-PO4−3 L−1–9.53 µg P-PO4−3 L−1 and <11 µg N-NH4+ L−1–9.57 µg N-NH4+ L−1) than during the dry season (<6 µg P-PO4−3 L−1–13.64 µg P-PO4−3 L−1 and <11 µg N-NH4+ L−1–14.43 µg N-NH4+ L−1), which may be related to low rainfall (0, 00–26, 16 mm) during the sampling period. The dry season showed enrichment of ammonium, phosphate, and chlorophyll a due to the influence of the coastal upwelling for the intensification of the Papagayo winds from December to March. The physical, chemical, and biological indicators demonstrated that the Gulf waters had adequate quality. Nonetheless, there are specific areas such as Culebra Bay with conditions that could show deterioration of water quality.

scholarly journals Impact of sea level rise on current and wave in Van Uc coastal area

2019 ◽  
Vol 19 (3) ◽  
pp. 313-325
Author(s):  
Nguyen Minh Hai ◽  
Vu Duy Vinh ◽  
Tran Dinh Lan
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
Wave Height ◽  
Coastal Area ◽  
Rainy Season ◽  
Dry Season ◽  
Navigation Channel ◽  
Current Scenario ◽  
Outer Area

This paper presents the results of analysis, comparison of some characteristics of current, wave at Van Uc estuary area when being affected by sea level rise due to climate change based on Delft3D model. Scenario groups are established: The current scenario and the scenarios simulating effect of sea level rise 0.5 m and 1.0 m. The results of calculation and simulation show that the velocity values change locally when sea level rises: Rise in the northern and southern areas (0.2–5 cm/s); decrease in the navigation channel (0.6–30 cm/s). Sea level rise causes the increase of wave height in the coastal area (13.5–43.8% in the dry season and 20–40% in the rainy season) and fewer changes in the outer area.

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