scholarly journals Geomorphometric and Terrain Analysis of the Nigerian Section of the Chad Basin (Bornu Basin) Northeastern Nigeria

2019 ◽  
Vol 11 (4) ◽  
pp. 1
Author(s):  
Yakubu Mohammed ◽  
Ibrahim B. Wulo ◽  
John Abdullahi ◽  
Aishe K. Gazali ◽  
Zanna A. Lawan ◽  
...  
Keyword(s):  
Sand Dunes ◽  
Morphological Characteristics ◽  
Holistic Approach ◽  
Landscape Configuration ◽  
Mapping Technique ◽  
Terrain Analysis ◽  
Land Form ◽  
Lake Chad ◽  
Shuttle Radar Topographic Mission ◽  
Temporal Dimensions

The aim of this paper is to characterize the geomorphology and analyze the terrain of the Bornu basin. This is critical to the understanding of the general landscape configuration, its evolution and morphodynamics in the basin. Mapping was carried using the Shuttle Radar Topographic Mission (SRTM) and Digital Elevation Model (DEM) data of the area. These set of data compliments the data generated from an extensive and detailed mapping of the area adopting the holistic approach geomorphologic field mapping technique. The basins slope generated from DEM of the area indicated five terrain categories. The western end of the basin has the highest slope of 755 to 1582m denoting the margins of the Biu and Jos plateau which slopes down to the lowest slope category of 256m at the shores of Lake Chad. These slope categories exhibits a variety of land forms ranging from rills, gullies, ponds, rivers, deltas, alluvial plains, ridges, hills and sand dunes of variable sizes, shapes and morphological characteristics. The Bama ridge which rises to height of 363m covering a distance of about 340 Km is a major land form in the basin. These land forms and others identified have been formed and are being fashioned by interplay of fluvial and Aeolian processes whose linkages are found to vary both in spatial and temporal dimensions.

A new species of short-fingered geckos Stenodactylus (Squamata, Geckonidae) from South Iran with taxonomic notes on validity of the genus Trigonodactylus Hass, 1957

Zootaxa ◽  
2018 ◽  
Vol 4457 (1) ◽  
pp. 93 ◽  
Author(s):  
ROMAN A. NAZAROV ◽  
DANIEL A. MELNIKOV ◽  
MEHDI RADJABIZADEH ◽  
NIKOLAY A. POYARKOV
Keyword(s):  
New Species ◽  
Sand Dunes ◽  
Morphological Characteristics ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
Color Pattern ◽  
Khuzestan Province ◽  
Longitudinal Line ◽  
Southwestern Iran ◽  
A New Species

In the present study we provide evidence for the validity of the genus Trigonodactylus Hass, 1957, improve the diagnosis for this genus and describe a new species that belongs to it—Trigonodactylus persicus sp. nov., from the sand dunes in Khuzestan Province, southwestern Iran. The new species is closely related to Trigonodactylus [Stenodactylus] arabicus sensu Hass, and can be distinguished by the following morphological characteristics: small size, maximum SVL 34 mm; SVL/TailL—approximately 1:1; ventral scales roundish, weakly keeled, 54–61 longitudinal rows at midbody and 190–25 along midbody. No enlarged postmentals. Fingers and toes slightly flattened dorso-ventrally. Lateral edge of digits fringed by series of projecting triangular scales. No web between digits. No preanal and femoral pores. Dorsal color pattern formed by thin, dark, irregular vermicular patches and spots. Sometimes these dark dorsal patterns blend with each other and form transverse bands. There is a narrow, dark, longitudinal line between forelimbs and hindlimbs on lateral sides. Dark, well developed ʌ-shaped marking on snout, which continues behind orbit on tympanum region, approaches the upper ear opening and ends on the pectoral arch. Labial scales white, in some cases with grey-brown dots. Dorsal surfaces of limbs and digits with irregular dark bands. Dorsal surface of tail with 8–10 wide, dark brown bands with irregular margins, same size as alternating light bands. Ventral surface of body and limbs white, tail with dark spots that become more distinct posteriorly.

scholarly journals The Use of SAR Offset Tracking for Detecting Sand Dune Movement in Sudan

2020 ◽  
Vol 12 (20) ◽  
pp. 3410
Author(s):  
Ahmed Mutasim Abdalla Mahmoud ◽  
Alessandro Novellino ◽  
Ekbal Hussain ◽  
Stuart Marsh ◽  
Panagiotis Psimoulis ◽  
...  
Keyword(s):  
Wind Speed ◽  
Rural Communities ◽  
Sand Dunes ◽  
Mapping Technique ◽  
Dune Field ◽  
High Resolution Images ◽  
Sand Movement ◽  
Different Characteristics ◽  
Offset Tracking ◽  
The Impact

Sand movement is one of the main environmental hazards in Northern Sudan that threaten livelihood and rural communities. This paper investigates for the first time the use of the Synthetic Aperture Radar (SAR) offset tracking technique for detecting sand movement in Northern Sudan, and distinguishes the impact of the movement influencing factors: wind speed/direction, vegetation and topography. High-resolution images from the Sentinel-1 satellite were used for the generation of displacement maps. Three different dune fields with different characteristics were investigated for a study period between 4 June and 14 October 2017 (133 days). Dune field 1 is vegetated and near a built-up area, dune field 2 is in an open environment with sand dunes overlaying rocky substrate, and dune field 3 is located near mountains. The cumulative east displacement over the study period was 1.8 m, −1.1 m and 4.8 m for the three dune fields, respectively, while the cumulative north displacement was 0.7 m, 2.9 m and 4.2 m. Large movement is detected in the non-vegetated dune fields, with an average dune velocity of 0.18 m/d, while the vegetated dune field had a velocity of 0.09 m/d, which emphasizes the fact that vegetation is an effective stabiliser of dune movement. The pixel offset results showed a positive correlation between the wind speed/direction and the dune movement. In addition to vegetation, topography also played a major role in diverting the direction of the blown sand mainly near the edges to the mountains and the vegetation barriers. This technique showed high competency in monitoring the movement of sand dunes, in addition to identifying areas exposed to large sand drifting as a risk mapping technique.

A new saprotrophic species of Amanita (Amanitaceae, Agaricales) from Inner Mongolia, China

Phytotaxa ◽  
2021 ◽  
Vol 527 (4) ◽  
pp. 284-292
Author(s):  
XIAOLIANG LIU ◽  
TOLGOR BAU ◽  
ZHU L. YANG
Keyword(s):  
Related Species ◽  
Internal Transcribed Spacer ◽  
Inner Mongolia ◽  
Northeast China ◽  
Large Subunit ◽  
Sand Dunes ◽  
Morphological Characteristics ◽  
The Common

A new saprotrophic species in Amanita sect. Lepidella, A. orientisororia, was discovered on lawn and sand dunes in Northeast China. This species was macroscopically characterized by a small white pileus, conical to subconical to pyramidal volval remnants on pileal surface, large broadly ellipsoid to ellipsoid basidiospores measuring 9–13×7–9.5 μm, and the common presence of clamps in all parts of basidiomata. It was described and compared with related species in the genus, based on morphological characteristics and phylogenetic evidence inferred from sequences of the nuclear ribosomal internal transcribed spacer (ITS) and the large subunit of the nuclear ribosomal region (nrLSU).

scholarly journals Discovering the Health Promoting Potential of Fermented Papaya Preparation—Its Future Perspectives for the Dietary Management of Oxidative Stress During Diabetes

Fermentation ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 83 ◽  
Author(s):  
Jhoti Somanah ◽  
Manish Putteeraj ◽  
Okezie Aruoma ◽  
Theeshan Bahorun
Keyword(s):  
Oxidative Stress ◽  
Free Radical ◽  
Stress Reduction ◽  
Senile Dementia ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Morphological Characteristics ◽  
Holistic Approach ◽  
Amino Acid Profile ◽  
Protective Effects

The simplistic morphological characteristics of Carica papaya fruit or “pawpaw” should not be the cause for underestimating its potential as a nutraceutical. The market for papaya has been expanding at a staggering rate, partly due to its applicability as a biofortified product, but also due to its phytochemical properties and traditional health benefits. Papaya or formulations of fermented papaya promotion (FPP) display effective free radical scavenging abilities thought to be influenced by its phenolic, carotenoid, flavonoid, or amino acid profile. The antioxidant properties of FPP have been extensively reported in literature to potently target a broad spectrum of free radical-induced diseases ranging from neurological impairments, such as senile dementia, to systemic diseases, to its interference at the cellular level and the support of normal biological ageing processes. FPP has thus been extensively investigated for its ability to exert cellular protective effects and reduce oxidative stress via the mitigation of genetic damage, reduction of lipid peroxidation, and enzymatic inactivation in specific diseases. The focus of this review is to appraise the potential of oxidative stress reduction strategies of FPP and discuss its holistic approach in disease prevention and management, with a particular focus on diabetes and cancer. However, with the current lack of information surrounding its mechanism of action, this review wishes to set the stage and aspire researchers to more profoundly investigate molecular pathways related to how FPP can unequivocally contribute to wellness in an aging population.

Nitrate pollution in groundwater in two selected areas from Cameroon and Chad in the Lake Chad basin

Water Policy ◽  
2010 ◽  
Vol 12 (5) ◽  
pp. 722-733 ◽  
Author(s):  
Benjamin Ngounou Ngatcha ◽  
Djoret Daira
Keyword(s):  
Urban Area ◽  
Urban Expansion ◽  
Sand Dunes ◽  
Shallow Aquifer ◽  
Lake Chad ◽  
Chad Basin ◽  
Lake Chad Basin ◽  
Nitrate Concentrations ◽  
Primary Origin ◽  
High Concentrations

The shallow aquifer in the Lake Chad basin is highly vulnerable to pollution. Analysis carried out on 316 wells and boreholes have showed a tendency towards an increase of nitrate values, exceeding 50 mg l−1. Nitrate concentrations ranged between about 1 and 300 mg l−1. Large variation in concentration was observed in wells and boreholes that are only short distances apart. High concentrations of nitrate in wells, especially in a recharge area along the sand dunes, or via infiltration from river banks, irrigation channels, and infiltration of urban wastewater into groundwater from septic tanks, pose a serious problem for drinking water supply. In Cameroon and Chad, the results of the investigation indicate a variation of nitrate concentration in groundwater between the two areas. The primary origin of this pollution is agricultural proliferation activities that are developed and stressed by socio-economic needs outside the urban area, and by urban expansion within the area served by a decrepit network of urban area sewers. Substancial differences in values of nitrate concentrations were observed in groundwater from adjacent wells and boreholes, indicating local rather than regional contamination.

scholarly journals GIS-Based Digital Terrain Analysis of Assam-Meghalaya Foothills in Kamrup District, Assam

2021 ◽  
Vol 20 (4) ◽  
Author(s):  
C. Borpujari ◽  
A. K. Bora
Keyword(s):  
Geographical Information ◽  
Terrain Analysis ◽  
Gis And Remote Sensing ◽  
Shuttle Radar Topographic Mission ◽  
Detailed Assessment ◽  
Spatio Temporal ◽  
Remote Sensing Techniques ◽  
Elevation Model ◽  
The Impact ◽  
Terrain Characteristics

Terrain characteristics and their evaluation usually come under geomorphological study and more particularly the applied geomorphological study (Prasad & Sarkar 2011). Foothills are a geographically defined zone having a gradual increase in elevation at the base of a mountain or hill range. Detailed assessment of the present terrain parameters of the study area using GIS is significant as it shows the influence on the landscape of the area. It is a prerequisite in effective management of the impact of transition upon the landscape and its natural resources for sustainable management. In the study, an attempt has been made to delineate the foothill belt of the Assam-Meghalaya border in Kamrup District, Assam using Geographical Information system (GIS), and remote sensing techniques. Datasets available from USGS Earth Explorer, i.e. Shuttle Radar Topographic Mission (SRTM) and Digital Elevation Model (DEM) are used for analyzing the elevation, contour, slope, and terrain characteristics. The present study aims at getting an information archive of the geomorphological and terrain characteristics of the Assam-Meghalaya foothills in Kamrup District, Assam, and its spatio-temporal variation.

scholarly journals Numerical classification and digital mapping of coastal plain sands of Southeastern Nigeria

Agro-Science ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 13-22
Author(s):  
J.C. Obi ◽  
I.B. Udoh ◽  
F.R. Adefila ◽  
U.E. Brownson
Keyword(s):  
Coastal Plain ◽  
Flow Direction ◽  
Morphological Characteristics ◽  
Mapping Technique ◽  
Regression Kriging ◽  
Soil Series ◽  
Digital Technique ◽  
Southeastern Nigeria ◽  
Digital Mapping ◽  
Terrain Attributes

The study classified the coastal plain sands of south-eastern Nigeria at the series level and modeled the classification using digital terrain attributes. The study utilized 72 secondary and 12 primary profile pits data generated from 24 and 4 locations (at 3 per location) for classification/modelling and validation respectively. The three profile pits per location represents the three topographic positions of upper, middle and lower slopes. Digital elevation model was also utilized for the generation of terrain attributes. Soil morphological characteristics were coded for suitability in statistical analysis. Hierarchical clustering was utilized in the grouping of the soil into 17 homogeneous groups referred to as soil series. Regression kriging was used to model the predicted soil series within the area covered by coastal plain sands in Akwa Ibom State. The variables that could be used in the modelling of the different classified soil series include Sand Content, aspect, flow accumulation, compound topographic index (CTI), elevation, hill shade, slope, curvature, flow direction, stream power index (SPI), profile curvature, tangential curvature (R2 = 0.21).Out of the 17 soil series classified, 14 was successfully mapped using digital technique. It was observed that 66.7% of the classified soil series were accurately predicted using digital mapping technique. The classifications carried out numerically made use of morphological discrete variables whereas digital used empirically determined continuous variables which could be more accurate. Therefore it could be inferred that the digitally produced soil  classification is more accurate and 14 soil series could be identified and mapped in the study area. Key words: pedogenesis, digital soil mapping, soil series, hierarchical clusters, regression kriging

scholarly journals Modelagem automática e cálculo da precipitação média da Bacia Hidrográfica do Rio Mundaú

2020 ◽  
Vol 9 (10) ◽  
pp. e4919108867
Author(s):  
Anderson Santos da Silva ◽  
Mário Melquíades Silva dos Anjos ◽  
Anthony Wellington Almeida Gomes ◽  
Alan Cézar Bezerra ◽  
Miguel Julio Machado Guimarães
Keyword(s):  
Digital Elevation Models ◽  
Terrain Analysis ◽  
Shuttle Radar Topographic Mission ◽  
Digital Elevation

As bacias hidrográficas desempenham um papel fundamental no desenvolvimento territorial desde que a exploração dos recursos naturais seja equilibrada tanto pela população quanto na gestão dos órgãos competentes. Assim, objetivou-se nessa pesquisa a delimitação automática e cálculo da precipitação média da Bacia Hidrográfica do Rio Mundaú (BHRM). A imagem foi processada no software livre QGIS 2.18.7 utilizando o conjunto de ferramentas embarcado no TauDEM (Terrain Analysis Using Digital Elevation Models) que dimensiona toda malha hidrológica através do uso de Modelo digital de Elevação (MDE) provenientes de dados altimétricos de imagem SRTM (Shuttle Radar Topographic Mission). Foi realizado todo tratamento na modelagem da rede de drenagem observando as remoções de depressões, declividades, canal principal, direções dos fluxos simples e múltiplos. Em seguida foi realizado o cálculo de precipitação média pelo método de Thiessen com subsídio de dados pluviométricos coletados em estações meteorológicas presentes no perímetro da bacia. Para complementação do trabalho, foram feitas umas caracterizações do relevo com uso do MDE obtido e assim corroborar com a interpretação dos resultados encontrados. Ficaram constatadas diferenças significativas entre os índices pluviométricos da BHRM entre o período de 2013 até 2019, pois no início da observação, o estado de Pernambuco e Alagoas vinha passando por um período de estiagem significativo justificando assim o reduzido volume pluviométrico. Em relação ao cômputo da área, houve uma diferença de mais de 400 km² na área da BHRM quando correlacionado com as informações dos órgãos oficiais, representando uma redução de aproximadamente 10%.

scholarly journals Generating and analyzing Terrain characteristics from Shuttle Radar Topographic Mission (SRTM), DEM

2021 ◽  
Vol 10 (3) ◽  
pp. 198-206
Author(s):  
Ugbelase Vincent Nwacholundu ◽  
Igbokwe Joel Izuchukwu ◽  
Emengini Josephine Ebele ◽  
Ejikeme Joseph Onyedika ◽  
Igbokwe Esomchukwu Chinagorom
Keyword(s):  
Flow Direction ◽  
Digital Elevation Models ◽  
Random Noise ◽  
Analysis Tool ◽  
Terrain Analysis ◽  
Srtm Dem ◽  
Hydrologic Modelling ◽  
Shuttle Radar Topographic Mission ◽  
Digital Terrain ◽  
Digital Elevation

Terrain analysis is the quantitative analysis of topographic surfaces. The purpose of a digital terrain system is to provide the digital representation of terrain so that environmental problem like soil erosion may be approached accurately and efficiently through automated means. Traditionally this was (and still is!) being done manually by using topographic/contour maps. With the availability of Digital Elevation Models (DEM) and GIS tools, watershed properties can be extracted by using automated procedures. Remote Sensing and Digital elevation models (DEMs) are known to be very useful data sources for the automated delineation of flow paths, sub watersheds and flow networks for hydrologic modelling and watershed characterization. The digital terrain model was extracted from a 90m resolution Shuttle Radar Topographic Mission (SRTM) of the study area. The SRTM data was corrected by removing voids, striping, tree offsets and random noise. The SRTM DEM data was projected from geographic coordinate WGS 84 to UTM zone 32 of the study area. The 3-D analysis tool of the ArcGIS 10.1 was used for this process. The DEM was processed to obtain the Slope, Contour, Flow direction, Flow accumulation, Flow length, Stream power Index of the study area. The study proved that SRTM elevation dataset has the ability to obviate the lack of terrain data for hydrologic modelling using ArcGIS where appropriate data for terrain modelling and simulation of hydrological processes is unavailable.

scholarly journals Conceptualising the Circular Economy Potential of Construction and Demolition Waste: An Integrative Literature Review

Recycling ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 61
Author(s):  
Vasilios Papastamoulis ◽  
Kerry London ◽  
Yingbin Feng ◽  
Peng Zhang ◽  
Robert Crocker ◽  
...  
Keyword(s):  
Literature Review ◽  
Circular Economy ◽  
Holistic Approach ◽  
The Body ◽  
Construction And Demolition Waste ◽  
Future Research ◽  
Demolition Waste ◽  
Five Dimensions ◽  
Body Of Knowledge ◽  
Temporal Dimensions

Traditionally, construction and demolition waste (CDW) materials have been considered to be unwanted, surplus, or wastage materials or materials with zero value. Such a conceptualisation only embraces a negative aspect, which underpins the disposal of reusable and recyclable CDW materials in landfills, thus damaging the circular economy and the environment. The scope of this research was to conceptualise the circular economy potential of non-hazardous construction and demolition waste, which can be used as a resource for advancing the circular economy and sustainability in the built environment. Thus, the abbreviation ‘CEPCDR’ is used for this purpose. The study employs an integrative literature review to understand in depth whether the rationale in the existing CDW definitions advocates for the circular economy. Instead, the literature showed that the current definitions mainly support quantitative, economic, or classification needs, respectively. That is because they lack consideration of the dynamic nature of CDW materials, which embraces the spatial and temporal dimensions. The former involves the geographic context in which the CDW phenomenon eventuates, while the latter concerns the lifecycle of materials. This study contributes to the body of knowledge by conceptualising the CEPCDR using a holistic approach that includes five dimensions: the social, economic, environmental, spatial, and temporal perspectives. Furthermore, the study seeks to drive future research in measuring the CEPCDR.

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