scholarly journals Spatial and Seasonal Dynamics of Total Suspended Sediment, Total Dissolved Solids and Turbidity of a Lacustrine Reservoir in the Magoye Catchment, Southern Zambia

2021 ◽  
Vol 2 (6) ◽  
pp. 43-48
Author(s):  
Manoah Muchanga ◽  
Henry M. Sichingabula
Keyword(s):  
Suspended Sediment ◽  
Seasonal Dynamics ◽  
Rainy Season ◽  
Anthropogenic Activities ◽  
Control Variable ◽  
Dry Season ◽  
Physical Parameters ◽  
Quality Of Water ◽  
Cool Dry Season ◽  
Concentration Levels

Dissolved and suspended sediment that form part of the Total Sediment Load (TSL) affects the quality of water making it unsuitable for selected aquatic invertebrates and livestock. The study aimed at determining spatial and seasonal dynamics in the concentration levels and distribution of selected physical parameters in a small lacustrine system whose main problem was punctuated by rapid deposition of clastic and none-clastic sediment. Water sampling was done during the rainy and cool-dry seasons across the reservoir using sampling bottles and DGPS. Laboratory analysis was done to determine variations in concentration levels of the parameters over time and space. Distributions of selected parameters across the reservoir were analysed using 3D Spatial Analysts Tool, Inverse Distance Weighted (IDW) in ArcGIS 10.2. Using paired T-Test at 0.05 level of significance, the study found statistically significant differences (p<0.001) in the concentration of TDS, TSS, and turbidity between the rainy season and cool-dry season. With exception of TDS, TSS and turbidity were higher in the rainy season than in the cool-dry season. Rainfall was the main control variable regarding seasonality influence on TDS, TSS, and turbidity. The study concluded that although lacustrine reservoirs may be closed systems, they still experience variations spatially and temporally in terms of concentration of TDS, TSS and turbidity. The study recommends implementation of integrated catchment-wide management of anthropogenic activities so as to minimize excess generation, transportation and deposition of sediment, which punctuate elevated levels of TDS, TSS and turbidity.

scholarly journals Heavy Metals in Water, Soils and Sediments of La Villa River Basin- Panama

2021 ◽  
pp. 1-12
Author(s):  
José Villarreal Núñez ◽  
Adolfo Santo Pineda ◽  
Jhon Villalaz Pérez ◽  
Iván Ramos Zachrisson
Keyword(s):  
Heavy Metals ◽  
River Basin ◽  
Water Samples ◽  
Rainy Season ◽  
Anthropogenic Activities ◽  
Great Influence ◽  
Dry Season ◽  
High Concentration ◽  
South Central ◽  
Rectangular Area

Determine the concentration of heavy metals in water, sediments, and crops within the La Villa river basin, Herrera and Los Santos provinces, republic of Panama. La Villa river Basin, south central of Panama, in the rainy season of 2016 (May to November) and in the dry season of 2017 (December to April). Twenty two sediments and water samples were taken using the systematic method which consists of selecting sampling points at uniform distances and crops in upper, middle and lower basin. The selected sampling was confined to a preferably rectangular area of 10.0 m x 30.0 m, on which the sub-samples were taken with a number of 15 on each grid, at 0.20m depth. For collecting the water samples, a rod with a clean plastic bottle was introduced against the current of the river. The digestion of sediments and crops to determine the concentration of heavy metals (As, Pb, Cr, Ni, Cu, Mn, Zn and Cd) was carried out according to USEPA (25) method (3051A) (SW-846). In the sediments, in the rainy season, Cu (upper and lower basin) and Mn (all levels) values were found above the USEPA Standards. In the dry season, high values of Mn were found in the middle and lower basin, Cr in the upper and lower basin and As in all areas of the basin. In the rainy and dry seasons, high levels of Mn, Zn, Cr, Cd and Pb were found in the waters of the rivers that make up the basin. The main crops at each height of the basin were analyzed, determining high levels of As and Cr in the upper basin, in the middle and lower basin Cr and Cd. It is necessary to monitor the concentration of heavy metals in sediments of La Villa river basin because 90% of the agrochemicals that enter the country is destined for agriculture. Each Panamanian consumes (does not ingest) 3 kg of agrochemicals annually, exceeding six times the amount used in Central America.  Due to their geological origin, these soils are rich in copper, manganese and arsenic, latter being associated with iron oxides and sulfides but there is also great influence of anthropogenic activities, agriculture and industries. Some metals such as lead and arsenic showed low solubility in water but showed high concentration in sediments. Chromium and cadmium present in crops come from water.

scholarly journals Ecology of Anopheles Mosquito Larvae in Different Ecological Zones in Ghana

2021 ◽  
Author(s):  
Isaac Amankona Hinne ◽  
Simon Kwaku Attah ◽  
Benedicta Ayiedu Mensah ◽  
Akua Obeng Forson ◽  
Yaw Asare Afrane
Keyword(s):  
Rural Communities ◽  
Rainy Season ◽  
Anthropogenic Activities ◽  
Temporal Distribution ◽  
Larval Habitat ◽  
Dry Season ◽  
Effective Control ◽  
Mosquito Larvae ◽  
Ecological Zones ◽  
Breeding Habitats

Abstract Background: Understanding the ecology of larval malaria mosquitoes is important in a changing environment is important in developing effective control tools or programmes. This study characterized the breeding habitats of Anopheles mosquitoes in rural communities in different ecological zones in Ghana during the dry and rainy seasons.Methods: The spatio-temporal distribution, species composition, and abundance of larval Anopheles mosquitoes in breeding habitats were studied in 3 ecological zones of Ghana. These were Anyakpor (Coastal Savanna area), Duase (Forest area), Libga, Pagazaa, and Kpalsogu (Sahel Savanna area). Larvae were collected using standard dippers and were raised in the insectary for identification. Results: Out of a total of 7,984 mosquito larvae collected, 2,152 (27.26%) were Anophelines and were more abundant in the rainy season (70.82%) than in the dry season (29.18 %). The Anophelines were made up of 2,128 (98.88%) An. gambiae s.l., 16 (0.74%) An. rufipees and 8 (0.37%) An. pharoensis. In Anyakpor and Duase, dug-out wells were the most productive habitat in the dry (1.59 larvae/dip and 1.47 larvae/dip) and rainy seasons (11.28 larvae/dip and 2.05 larvae/dip). The most productive habitats in Kpalsogu were natural ponds in the dry season (0.89 larvae/dip) and swamps in the rainy season (2.57 larvae/dip). In Libga, the most productive habitats were drainage ditches in the dry season (0.30 larvae/dip) and furrows in the rainy season (1.83 larvae/dip). The most productive habitats in Pagazaa were puddles (1.44 larvae/dip). Anopheles coluzii was the most abundant sibling species in all the ecological zones except Libga in the sahel savannah area where An. gambiae s.s was the most abundant. Anopheles melas and An. arabiensis were encountered only in the coastal savannah and the sahel savanna areas respectively. Larval habitat types influenced the presence of larvae as well as larval densities (p < 0.001). The land-use type affected the presence of Anopheles larvae (p = 0.001), while vegetation cover influenced larval densities (p < 0.05). Conclusion: The study revealed that the abundance of Anopheles breeding habitats and hence Anopheles larvae are closely associated with anthropogenic activities. Regulating such activities will lead to a significant reduction in Anopheles breeding habitats.

scholarly journals ASSESSMENT OF THE SEASONAL DYNAMICS OF THE NORMALIZED DIFFERENTIAL VEGETATION INDEX (NDVI) AND ITS CORRELATION WITH CLIMATE PREDICTORS IN WETLANDS “LA TEMBLADERA” (ECUADOR)

Ekosistemy ◽  
2021 ◽  
pp. 5-11
Author(s):  
S. A. Llerena ◽  
A. I. Kurbatova
Keyword(s):  
Climate Change ◽  
Seasonal Dynamics ◽  
Rainy Season ◽  
Vegetation Index ◽  
Climatic Factors ◽  
Dry Season ◽  
Climatic Variables ◽  
Regulatory Function ◽  
Temperature And Precipitation ◽  
Dynamics Of Vegetation

Wetlands are considered critical ecosystems due to declining quality of their ecosystems services. Nevertheless, there have not been any climate related researched devoted to vegetation condition and biomass amount. Thus, this study examines the seasonal dynamics of vegetation and its correlations with climatic factors. This study is important for understanding of the regulatory function of this ecosystem during climate change. Two Landsat OLI8 images made in 2020 were analyzed. One image refers to the rainy season (April 12), and the other to the dry season (August 2). The radiometric and atmospheric corrections of the images and the determination of the boundaries of the study site (ROI) were developed in ENVI 5.3 program. The normalized differential vegetation index (NDVI) was calculated with ENVI 5.3 program (histograms allowed to determine biomass), and with ArcGIS 10.3 (for classification index). The Pearson coefficient (r) and the Statistica software were applied to determine the correlations between the variables. The linear relationship between the NDVI, the amount of biomass and the climatic variables was identified. In the rainy season (April) with higher temperature and precipitation, the NDVI was >0.5 and the biomass was 372613.0 t in the major part of “la Tembladera”, while in the dry season (August) with a lower temperature and precipitation rate, both the NDVI (0.14–0.5) and the biomass (333856.95 t) decreased in a considerable area of the wetland. Consequently, the seasonal dynamics of vegetation and its biomass is caused by fluctuations in these climatic variables. Thus, the biomass increased during the rainy season (higher precipitation, temperature, and humidity). These results can be used to further modelling the effects of climate change in these ecosystems.

scholarly journals Simulation of suspended sediment and black carbon transport in surface water layer of Ha Long bay

2019 ◽  
Vol 19 (2) ◽  
pp. 233-241
Author(s):  
Le Duc Cuong ◽  
Nguyen Van Thao
Keyword(s):  
Surface Layer ◽  
Black Carbon ◽  
Suspended Sediment ◽  
Suspended Matter ◽  
Rainy Season ◽  
Water Layer ◽  
Dry Season ◽  
Particulate Carbon ◽  
The North ◽  
Long Bay

Delft3D model employed to simulate the distribution and transport of suspended sediment and black carbon in Ha Long bay shows outcomes meeting with results from previous experiment studies. In the rainy season, suspended matter in surface layer is mainly in waters of western and southwestern Cat Ba island regions, and from Cua Luc toward the south nearshore areas with concentration of 50–130 g/m3. The concentration of suspended setdiment in the waters from Cua Luc to the north nearshore area is from 20 g/m3 to 50 g/m3 and that of offshore areas is 2–20 g/m3. In the dry season, the average concentrations of suspended matter are lower, approximately 110–150 g/m3 compared to the rainy season. In the rainy season, the total particulate carbon in surface layer is 0.0016–0.0028 kg/m3 and in the dry season, it ranges from 0.0001–0.005 kg/m3.

scholarly journals Calidad Microbiológica Del Agua En La Cuenca Media Del Río Usumacinta, Tabasco, México

2018 ◽  
Vol 14 (9) ◽  
pp. 46
Author(s):  
Temani Durán-Mendoza ◽  
José Ulises González-de la Cruz ◽  
Manuel González-Pérez ◽  
Carolina del Carmen Pérez-Sánchez ◽  
Raúl Hernández Gómez ◽  
...  
Keyword(s):  
Rainy Season ◽  
Pathogenic Bacteria ◽  
Microbiological Quality ◽  
Dry Season ◽  
Microbiological Analysis ◽  
Quality Of Water ◽  
Water Plant ◽  
Colony Forming Units ◽  
Del Rio

Some species of pathogenic bacteria such as Salmonella, Escherichia coli, Shigella, among others, are a threat to the ichthyofauna that lives in freshwater rivers. This threat extends to the human population that develops various activities in this environment. Food products derived from these activities can affect consumers as well. Therefore, the objective of this research was to evaluate the microbiological quality of water in the middle basin of the Usumacinta River, Tabasco, Mexico. A total of 63 water samples were collected in 12 sampling sites: 36 in the dry season and 27 in the rainy season in 2013. The microbiological analysis was carried out according to Mexican standards. The highest concentration of CT was detected in Usumacinta (Usu) (130 NMP / 100mL) during the dry season and in Petunia (Pet) (240 NMP / 100mL) during the rainy season. The highest concentration of CF was detected in the water plant (Pa), Pet and Estapilla (Est) (34 NMP / 100mL), during the rainy season. The results of CT and CF registered significant differences in the Colony Forming Units (CFU), due to seasonality (p <0.05). Thus, they were not significant due to the effect of the sampling sites (p <0.05). Also, 284 putative strains of enterobacteria isolated and identified mainly Escherichia sp and Salmonella sp in the two studied seasons. These results are one of the first evidences of the microbiological quality of water in the middle basin of the river Usumacinta, Mexico.

scholarly journals Aquatic entomofauna and biotic index along the Pindo Grande River, Montano Bajo Forest, in Pastaza Province, Ecuador

2021 ◽  
Vol 16 (1) ◽  
pp. 1
Author(s):  
Maria Alexandra Endara ◽  
Demián Hinojosa-Garró
Keyword(s):  
Water Quality ◽  
Rainy Season ◽  
Anthropogenic Activities ◽  
Conservation Status ◽  
Working Party ◽  
Principal Component ◽  
Dry Season ◽  
Biotic Index ◽  
Taxon Richness ◽  
Dry Seasons

Pindo Grande River water quality was analyzed during rainy seasons of 2014 and 2017 and dry seasons of 2015 and 2016. Specimens were collected using surber net, kick net and manual stone collection, from five different sites along the river. In the laboratory, specimens were identified to the lowest possible taxonomic level. Taxon richness, abundance, diversity, trophic niches, and Biological Monitoring Working Party for Colombia (BMWP/Col) index were assessed. A total of 1,695 specimens belonging to 95 taxa were collected, including 57 taxa in rainy seasons and 38 taxa in dry seasons. Class Insecta was the most abundant (98.6%). Richness was highest (3,427) at M1000 collection sites in rainy and dry seasons and varied from moderate to high (13–35) at other sites. All sampling sites had medium diversity, and organisms belonged to three trophic categories: herbivores, detritivores, and predators. Environmental water quality was medium at most sites (BMWP/Col = 102–150). All sites exhibited good conservation status (BMWP/Col = 192–152) in the rainy season; only two sites presented medium conservation status (BMWP/col = 93–67) in the dry season. Principal component analysis indicated that main variables associated with sites were NO3 and COD in upstream areas in the rainy season and O2 in the dry season. Downstream areas were grouped based on depth and width of the river in the rainy season and on pH, PO4, and conductivity in the dry season. According to analysis, the Pindo Grande River has preserved epibenthic communities; it is an oxygenated stream, but its habitats have been gradually affected by anthropogenic activities.

scholarly journals Dynamics Variation of Soil Labile Organic Carbon Fractions in Different Wetland Types of Dongting Lake under Seasonal Water Level Fluctuation

2021 ◽  
Vol 13 (24) ◽  
pp. 13836
Author(s):  
Ye Xiao ◽  
Zhigang Huang ◽  
Youfeng Li ◽  
Yulin Ling ◽  
Hanxi Xiao
Keyword(s):  
Enzyme Activity ◽  
Organic Carbon ◽  
Seasonal Dynamics ◽  
Catalase Activity ◽  
Rainy Season ◽  
Dongting Lake ◽  
Dry Season ◽  
Labile Organic Carbon ◽  
Soil Labile Organic Carbon ◽  
Wetland Types

Soil labile organic carbon (LOC) fractions are very sensitive to environmental change and closely related to soil quality. They play an important role in the study of terrestrial carbon cycles. This study aimed to explore the sensitivity of soil LOC fractions to environmental changes and analyze their main influencing factors during three seasonal water level periods for scientific management of Dongting Lake wetlands. Soil under three typical wetland types (Carextristachya wetland (CTW), Phragmites australis wetland (PAW) and Salix babylonica (SBW)) in East Dongting Lake in China were collected during the normal season (May), rainy season (August) and dry season (December). Seasonal dynamics of soil LOC fractions (i.e., dissolved organic carbon (DOC), microbial biomass carbon (MBC) and easily oxidized carbon (EOC)) within these wetlands and their relationship to soil nutrients and carbon-cycle enzyme activity were analyzed. The results showed that the soil DOC contents of the three wetlands first increased and then decreased, with the exception of CTW from the normal season to the dry season, while the seasonal changes of soil MBC and EOC for all wetlands followed an opposite pattern. CTW had the largest DOC concentration (228.29 mg·kg−1) during dry season, while the highest contents of soil DOC, MBC and EOC were found in PAW during the three observed seasons, which ranged from 82.05 to 203.60 mg·kg−1, 262.54 to 325.74 mg·kg−1 and 3.30 to 4.61 g·kg−1, respectively. However, the contents of soil DOC and their proportions to soil organic carbon (SOC) of all wetlands during the normal season were 56.58~82.05 mg·kg−1 and 0.41~0.47%, respectively, which were the lowest among the three seasons. Nevertheless, the contents of both MBC and EOC as well as their ratios to SOC in these wetlands showed similar seasonal dynamics, with the lowest values recorded in the rainy season. From the normal season to the dry season, invertase activity in all wetlands increased, while cellulase activity decreased by 12.5–31.3%. The seasonal variation of catalase activity for all wetlands was less distinctive, and the highest enzyme activity was during the rainy season. Correlation analysis revealed that soil LOC fractions for all wetlands were closely related to SOC, TN, TP and invertase for the three seasons, especially during the rainy season, but were negatively correlated with TK, cellulase and catalase activity. Generally, soil LOC fractions of the three wetlands were affected by the seasonal fluctuations of water levels and presented different distribution characteristics.

THE INITIAL RESULTS OF THE SUSPENDED SEDIMENT DYNAMICS DURING THE DRY SEASON IN THE HAU RIVER MOUTH AREA

2017 ◽  
Vol 17 (2) ◽  
Author(s):  
Nguyen Ngoc Tien ◽  
Dinh Van Uu ◽  
Nguyen Tho Sao ◽  
Do Huy Cuong ◽  
Nguyen Trung Thanh ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
River Mouth ◽  
Dry Season ◽  
Sediment Dynamics ◽  
Mouth Area ◽  
River Mouth Area ◽  
Initial Results

Hydro-geochemical properties with respect to landuse in the southernmost river of Kerala

2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Badusha M. ◽  
Santhosh S
Keyword(s):  
Organic Carbon ◽  
Drainage Basin ◽  
Anthropogenic Activities ◽  
Oxygen Demand ◽  
Ion Concentration ◽  
Total Hardness ◽  
Hydrogen Ion Concentration ◽  
Geochemical Properties ◽  
Quality Of Water

The hydro geochemical features of Neyyar River for a period of one year from May 2015 to April 2016 were analyzed. Six sampling sites were fixed considering physiography and present landuse pattern of the river basin. The residents in the drainage basin are primarily responsible for framing a better landuse and thereby maintain a good water and sediment regime. Geospatial pattern of the present landuse of the study area indicated that the sustainability of this river ecosystem is in danger due to unscientific landuse practices, which is reflected in the river quality as well. The parameters such as hydrogen ion concentration, electrical conductivity, chloride, Biological Oxygen Demand, total hardness and sulphate of river water and Organic Carbon of river bed sediments were analyzed in this study. The overall analysis shows that the highland areas are characterized by better quality of water together with low organic carbon, which is mainly due to better landuse and minimal reclamation. The midland and lowland areas are characterized by poor quality of water with high organic carbon, which is due to high anthropogenic activities and maximum pollutants associated with the region together with the alteration in landuse from a traditional eco-friendly pattern to a severely polluted current pattern.

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