scholarly journals Physico-chemical and bacteriological characterisation of surface water in Bamenda (North West Cameroon)

2021 ◽  
Vol 11 (12) ◽  
Author(s):  
Alice Magha Mufur ◽  
Margaret Tita Awah ◽  
Gus Djibril Kouankap Nono ◽  
Primus Azinwi Tamfuh ◽  
Pierre Wotchoko ◽  
...  
Keyword(s):  
River Water ◽  
Principal Component ◽  
Point Sources ◽  
Ion Concentration ◽  
City Centre ◽  
Physical Parameters ◽  
Water Type ◽  
North West ◽  
Physico Chemical ◽  
The City

AbstractThe Mezam River and its tributaries constitute a prominent water source for domestic use and vegetable irrigation in Bamenda Town (North West Cameroon). The river flows through the city and is thus vulnerable to impairment by substances from point and non-point sources. This current research aims to assess the degree of pollution of the Mezam River water to ascertain its suitability for various uses. A total of 24 water samples were collected from six segments of the Mezam River basin in the dry and rainy seasons during the years 2015 and 2016 in view of physico-chemical and bacteriological analyses. In situ measurement of physical parameters was taken in the field. The data were analysed by multivariate statistical techniques (principal component analysis and factor analysis). The results revealed that the river water is slightly acidic (pH = 5.45–6.47) and ion concentration is low (41.67–237.00 µS/cm). The water type is Ca-SO4 and Ca-Mg-(Cl + NO3) in the dry season and Ca-Mg-SO4 in the rainy season. High NO3− values (50 mg/l) are recorded at Nkimefueh. The Mezam River water is heavily polluted with indicator bacteria (0–500 CFU/100 ml) whose concentrations steadily increase from the reference point (YB) through sampling points in the city centre, suggesting the influence of human-induced activities. The population is urged to adopt a responsible behaviour towards waste disposal and refrain from disposing waste in water courses in order to safeguard the aquatic environment and also protect the health of the population.

scholarly journals Variations in time and space of trace metal aerosol concentrations in urban areas and their surroundings

2011 ◽  
Vol 11 (5) ◽  
pp. 14747-14776
Author(s):  
T. Moreno ◽  
X. Querol ◽  
A. Alastuey ◽  
C. Reche ◽  
M. Cusack ◽  
...  
Keyword(s):  
Trace Metal ◽  
Urban Areas ◽  
Urban Pollution ◽  
Sea Breeze ◽  
Point Sources ◽  
Fuel Oil ◽  
Physical Parameters ◽  
Spatial And Temporal Variability ◽  
Metal Concentrations ◽  
The City

Abstract. Using an unprecedentedly large geochemical database, we compare temporal and spatial variations in inhalable trace metal background concentrations in a major city (Barcelona, Spain) and at a nearby mountainous site (Montseny) affected by the urban plume. Both sites are contaminated by technogenic metals, with V, Pb, Cu, Zn, Mn, Sn, Bi, Sb and Cd all showing upper continental crust (UCC) normalised values >1 in broadly increasing order. The highest metal concentrations usually occur during winter at Barcelona and summer in Montseny. This seasonal difference was especially marked at the remote mountain site in several elements such as Ti and Rare Earth Elements, which recorded campaign maxima, exceeding PM10 concentrations seen in Barcelona. The most common metals were Zn, Ti, Cu, Mn, Pb and V. Both V and Ni show highest concentrations in summer, and preferentially fractionate into the finest PM sizes (PM1/PM10 > 0.5) especially in Barcelona, this being attributed to regionally dispersed contamination from fuel oil combustion point sources. Within the city, hourly metal concentrations are controlled either by traffic (rush hour double peak for Cu, Sb, Sn, Ba) or industrial plumes (morning peak of Ni, Mn, Cr generated outside the city overnight), whereas at Montseny metal concentrations rise during the morning to a single, prolonged afternoon peak as contaminated air transported by the sea breeze moves into the mountains. Our exceptional database, which includes hourly measurements of chemical concentrations, demonstrates in more detail than previous studies the spatial and temporal variability of urban pollution by trace metals in a given city. Technogenic metalliferous aerosols are commonly fine in size and therefore potentially bioavailable, emphasising the case for basing urban background PM characterisation not only on physical parameters such as mass but also on sample chemistry and with special emphasis on trace metal content.

scholarly journals SATELLITE-DRIVEN ASSESSMENT OF SURFACE URBAN HEAT ISLANDS IN THE CITY OF ZAGREB, CROATIA

2020 ◽  
Vol V-3-2020 ◽  
pp. 757-764
Author(s):  
A. Krtalić ◽  
A. Kuveždić Divjak ◽  
K. Čmrlec
Keyword(s):  
Vegetation Cover ◽  
Vegetation Index ◽  
Principal Component ◽  
Urban Heat Islands ◽  
City Centre ◽  
Landsat 8 ◽  
Heat Islands ◽  
Critical Areas ◽  
Urban Heat ◽  
The City

Abstract. This study aims to assess surface urban heat islands (SUHIs) pattern over the city of Zagreb, Croatia, based on satellite (optical and thermal) remote sensing data. The spatio-temporal identification of SUHIs is analysed using the 12 sets of Landsat 8 imagery acquired during 2017 (in each month of the year). Vegetation cover within the city boundaries is extracted by using Principal Component Analysis (PCA) data fusion method on calculated three vegetation indices (VI): Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI) and Ratio Vegetation Index (RVI) for each set of bands. The first principal component was used to compute the land surface temperature (LST) and deductive Environmental Criticality Index (ECI). As expected, the relationship between LST and all VI scores shows a negative correlation and is most negative with RVI. The environmentally critical areas and the patterns of seasonal variations of the SUHIs in the city of Zagreb were identified based on the LST, ECI and vegetation cover. The city centre, an industrial area in the eastern part and an area with shopping centers and commercial buildings in the western part of the city were identified as the most critical areas.

scholarly journals Building a predictive machine learning model of gentrification in Sydney

2021 ◽  
Author(s):  
William Thackway ◽  
Matthew Kok Ming Ng ◽  
Chyi Lin Lee ◽  
Christopher Pettit
Keyword(s):  
Machine Learning ◽  
City Centre ◽  
North West ◽  
Vulnerable Communities ◽  
Policy Interventions ◽  
South West ◽  
Socioeconomic Index ◽  
Machine Learning Model ◽  
Neighbourhood Change ◽  
The City

In an era of rapid urbanisation and increasing wealth, gentrification is an urban phenomenon impacting many cities around the world. The ability of policymakers and planners to better understand and address gentrification-induced displacement hinges upon proactive intervention strategies. It is in this context that we build a tree-based machine learning (ML) model to predict neighbourhood change in Sydney. Change, in this context, is proxied by the Socioeconomic Index for Advantage and Disadvantage, in addition to census and other ancillary predictors. Our models predict gentrification from 2011-2016 with a balanced accuracy of 74.7%. Additionally, the use of an additive explanation tool enables individual prediction explanations and advanced feature contribution analysis. Using the ML model, we predict future gentrification in Sydney up to 2021. The predictions confirm that gentrification is expanding outwards from the city centre. A spill-over effect is predicted to the south, west and north-west of former gentrifying hotspots. The findings are expected to provide policymakers with a tool to better forecast where likely areas of gentrification will occur. This future insight can then inform suitable policy interventions and responses in planning for more equitable cities outcomes, specifically for vulnerable communities impacted by gentrification and neighbourhood change.

scholarly journals EVALUATION OF POLLUTION LEVEL CAUSED BY DOMESTIC EFLUENT IN THE POTY RIVER – TERESINA PI - BRAZIL

2017 ◽  
Vol 37 (1) ◽  
pp. 51
Author(s):  
Izabele Folha Damasceno ◽  
Vivane Lopes Leal ◽  
Ronaldo Cunha Coelho ◽  
Carla Verônica Rodarte de Moura ◽  
Edmilson Miranda de Moura
Keyword(s):  
River Water ◽  
Water Samples ◽  
The Body ◽  
Pollution Level ◽  
Chemical Parameters ◽  
River Water Samples ◽  
Physico Chemical ◽  
The City

This article reports on the level of contamination of effluents, sediments and water in the Poty River, within the city of Teresina. The samples were collected in the months of September 2009, December 2009 and March 2010. The results of some physico-chemical parameters investigated, as well as the concentrations of lead, copper and nickel found in the river water samples showed that the body of water in the Poty River is unsuitable for use in various activities. These activities include direct recreational usage and primary irrigation of vegetables that are eaten raw as well as fruits that are eaten without removing films, among others.

scholarly journals Hydro-biological characterization and efficiency of natural waste stabilization ponds in a desert climate (city of Assa, Southern Morocco)

2021 ◽  
Author(s):  
Badre Achag ◽  
Hind Mouhanni ◽  
Abdelaziz Bendou
Keyword(s):  
Principal Component ◽  
Water Clarity ◽  
Organic Load ◽  
Low Oxygen ◽  
Rapid Urbanization ◽  
Waste Stabilization Ponds ◽  
Stabilization Ponds ◽  
Waste Stabilization ◽  
Physico Chemical ◽  
The City

Abstract The city of Assa is located in a Saharian area characterized by an arid climate and water scarcity. Like any other Saharian city in a developing country, the city is facing the challenges of rapid urbanization and the need to improve wastewater treatment and management. The main objective of this work is to assess the performance of waste stabilization ponds in an arid area. This evaluation concerns microbiological and physico-chemical monitoring over three and twelve months respectively. Microbiological results indicate bacterial elimination rates of over 90% in autumn–winter due to the effectiveness of facultative ponds with 20–25 days of retention time, water clarity, ponds depth, and high sunlight exposure and penetration. Physico-chemical parameters surpass the Moroccan standards for reuse except Ph and T0 by 20–30%, this wastewater is relatively loaded with various pollutants, especially high organic load and low oxygen content. Statistical analysis has been made by principal component analysis (PCA), and confirms that dissolved oxygen, total suspended solids, COD and BOD5 do not reach the threshold for discharge into the natural environment, and moreover their reuse. For the improvement of the quality of these waters, it is legitimate to provide an upgrade of this plant by a tertiary treatment with maturation ponds.

The aquatic oligochaetes (Annelida: Clitellata) of eight lakes in the Aşği Firat River Basin (Lower Euphrates, Turkey)

Biologia ◽  
2016 ◽  
Vol 71 (1) ◽  
Author(s):  
Seval Aras ◽  
Özlem Fındik
Keyword(s):  
River Basin ◽  
Principal Component ◽  
Point Sources ◽  
Eastern Anatolia ◽  
Chemical Parameters ◽  
Aquatic Oligochaetes ◽  
Physico Chemical ◽  
The Family ◽  
Species Composition And Distribution

AbstractThe Aşağ Fırat River is located in the south-eastern Anatolia, Turkey. The water quality of the Aşağ Fırat River basin has been degrading for some time, primarily as the result of pollutants associated with the discharges from numerous domestic and agricultural point sources. Aquatic macroinvertebrate samples were collected from eight lakes conducted by using both hand-nets and an Ekman-Birge grab sampler during the summer and autumn of 2014, focusing on the species composition and distribution of aquatic oligochaetes in eight lakes of the Aşağ Fırat River basin, and their relationships with physico-chemical parameters measured in those lakes using Principal Component Analysis. Results of analyses of all identified benthic macroinvertebrates clearly indicate the percent dominance of oligochaetes in benthic samples in the eight dam lakes that were sampled: Hacıhıdır lake (62.9%); Atatürk lake (49.6%); Üçöz lake (28.9%); Dumluca lake (22.01%); Seve lake (13.9%); Çat lake (8.5%); Karakaya lake (7.8%) and Birecik lake (5%). During this study, 1044 oligochaete specimens representing 10 species of two subfamilies within the family Naididae were identified. The most abundant taxa were

scholarly journals Feline patent Toxoplasma-like coccidiosis among feral cats (Felis catus) in Doha city, Qatar and its immediate surroundings

2014 ◽  
Vol 59 (3) ◽  
Author(s):  
Marawan Abu-Madi ◽  
Jerzy Behnke
Keyword(s):  
Felis Catus ◽  
City Centre ◽  
Clear Pattern ◽  
Hospital Records ◽  
Feral Cat ◽  
Feral Cats ◽  
North West ◽  
The City ◽  
Annual Period

AbstractDoha city has a high feral cat population and studies of hospital records in Doha have shown that human toxoplasmosis also occurs. Clearly, there is a need to understand the role of cats as vectors of human toxoplasmosis in the city and as a first step we assessed the extent of patent Toxoplasma-like coccidial infections among feral cats. Oocysts in cat faeces were detected between June 2008 and April 2010, from a range of locations radiating out of the city centre in concentric semi circular/elliptic rings and by north, west and south divisions within each of the rings. In total 4,652 cats were sampled and overall prevalence of oocysts was 9.1%. Prevalence was 10.1% in the first summer, and then dropped to 8.4% in the following winter and further to 6.8% in the next summer before rising to 10.6% in the final winter of the study; this interaction between annual period and season was significant. There were also significant changes in prevalence across each of the consecutive months of the study, but no clear pattern was evident. Prevalence did not vary significantly by city sector and there was no difference in prevalence between the host sexes. We conclude therefore, that despite minor and significant perturbations, the prevalence of patent Toxoplasma-like coccidial infections among cats in Doha is remarkably stable throughout the year, across years and spatially within the city’s districts.

scholarly journals Analysis of Water Quality of the Meghna River Using Multivariate Analyses and Rpi

2017 ◽  
Vol 43 (1) ◽  
pp. 23-35 ◽  
Author(s):  
Md Simul Bhuyan ◽  
Muhammad Abu Bakar ◽  
Aysha Akhtar ◽  
M Belal Hossain ◽  
Md Shafiqul Islam
Keyword(s):  
River Water ◽  
Pollution Index ◽  
Principal Component ◽  
River Pollution ◽  
Multivariate Statistical ◽  
Factors Analysis ◽  
Physico Chemical ◽  
Water Ph ◽  
Temperature Water

The present study was carried out to measure the physico-chemical variables of surface water of the Meghna River from September 2015 to March 2016. Air temperature, water temperature, soil pH, water pH, DO, BOD5, COD, TSS, TDS, PO4-P, NO3-N and EC concentrations in water samples were found to range from 14-29°C, 11-28°C, 5.9-6.9, 7.2-7.5, 4.2-6.71 mg/L, 0.67-3.71 mg/L, 2.5-5.9 mg/L, 8-20 mg/L, 72-130 mg/L, 0.11- 0.90 μg/l, 0.115-0.90 μg/l and 115.8-220 μScm-1 respectively. River Pollution Index (RPI) indicated that the water of river at impacted site was less to moderately polluted. Unimpacted site was also less polluted as per RPI and mostly used for agriculture. Correlation Matrix (CM) and Multivariate statistical analyses namely Cluster Analysis (CA), Principal Component Analysis (PCA) and Factors Analysis (FA) indicated that river water was polluted. The principal causes of the pollution of the river were haphazard industrialization, domestic sewage and agricultural inputs. Using of river water can pose serious problems to human health by biological food chain. This research suggests to proper management of the river with eco-friendly industrialization and urbanization for sustainable development of the country. Asiat. Soc. Bangladesh, Sci. 43(1): 23-35, June 2017

scholarly journals Direct determination of highly size-resolved turbulent particle fluxes with the disjunct eddy covariance method and a 12 – stage electrical low pressure impactor

2008 ◽  
Vol 8 (3) ◽  
pp. 8997-9034 ◽  
Author(s):  
A. Schmidt ◽  
O. Klemm
Keyword(s):  
Eddy Covariance ◽  
Aerosol Particles ◽  
Direct Determination ◽  
Low Pressure ◽  
West Germany ◽  
City Centre ◽  
Eddy Covariance Method ◽  
North West ◽  
Particle Fluxes ◽  
The City

Abstract. During summer 2007, turbulent vertical particle fluxes were measured for a period of 98 days near the city centre of Münster in north-west Germany. For this purpose, a valve controlled disjunct eddy covariance system was mounted at 65 m a.g.l. on a military radio tower. The concentration values for 11 size bins with aerodynamic diameters (D50) from 0.03 to 10 μm were measured with an electrical low pressure impactor. After comparison with other fluxes obtained from 10 Hz measurements with the classical eddy covariance method, the loss of information concerning high frequent parts of the flux could be stated as negligible. The results offer an extended insight in the turbulent atmospheric exchange of aerosol particles by highly size-resolved particle fluxes covering 11 size bins and show that the city of Münster acts as a relevant source for aerosol particles. Significant differences occur between the fluxes of the various particle size classes. While the total particle number flux shows a pattern which is strictly correlated to the diurnal course of the turbulence regime and the traffic intensity, the total mass flux exhibits a single minimum in the evening hours when coarse particles start to deposit. As a result, a mean mass deposition of about 10 g m−2 per day was found above the urban test site, covering the aerosol size range from 40 nm to 2.0 μm. By contrast, the half-hourly total number fluxes accumulated over the lower ELPI stages range from –4.29×107 to +1.44×108 particles m−2 s-1 and are clearly dominated by the sub-micron particle fraction of the impactor stages with diameters between 40 nm and 320 nm. The averaged number fluxes of particles with diameters between 2.0 and 6.4 μm show lower turbulent dynamics during daytime and partially remarkably high negative fluxes with mean deposition velocities of 2×10−3 m s−1 that appear temporary during noontime and in the evening hours.

scholarly journals Assessment of the seasonal variations in hydrochemistry of Oued Fodda dam, Algeria

2021 ◽  
Vol 9 (3) ◽  
pp. 78-90
Author(s):  
Abdelkader Bouderbala
Keyword(s):  
Surface Water ◽  
Seasonal Variations ◽  
Principal Component ◽  
Pollution Level ◽  
Water Type ◽  
Chemical Parameters ◽  
Multivariate Statistical ◽  
Physico Chemical ◽  
Water Volumes ◽  
And Cluster Analysis

Abstract This study was carried out on the surface water of Oued Fodda dam in western Algeria, and aimed to evaluate the seasonal variations of chemical characteristics with the aim to define the processes controlling the mineralization of surface water in this dam. The results showed significant variations in the majority of parameters during the study period from 2009 to 2013, indicating slightly alkaline water, and a SO4-Cl-Ca-Mg water type. Principal component analysis (PCA) and cluster analysis (CA) were used to explain the correlations between the parameters analysed, and the probable sources of surface water contamination. The calculation of saturation indices (SI) of water indicated undersaturated water with respect to halite (NaCl), and equilibrium with respect to the other minerals. While, the temporal variation of physico-chemical parameters such as EC, TDS, SO4 2-, Cl-, Ca2+, Mg2+ indicated a reverse adjustment between physico-chemical parameters and water volumes (WV) in this dam, which can be explained by the weathering of silicate and carbonate minerals, these were justified by the use of ionic ratios, diagrams and scatter plots and multivariate statistical techniques. Conversely, evaluation of the organic water pollution level in this dam showed a water quality from moderately to severely polluted.

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