CURRENT ISSUE

Vol. 3 No. 2 – October 2019

Articles


Spatial pattern of Land Surface Temperature over Umuahia North and Bende LGA, Abia State, Nigeria

Uchendu U. I, Kanu C., Kanu K. C. and Mpamah C. I.

https://doi.org/10.36263/nijest.2019.02.0138

ABSTRACT
This study evaluated the Spatial pattern of Land Surface Temperature (LST) over Umuahia North (Urban Area) and Bende LGA (Rural Area), Abia State, Southeast Nigeria. LANDSAT Imagery spanning Row 056 and Path 188, with 30m spatial resolution was captured on the 17th of May, 2018. Temperature and relative humidity were measured using a thermometer and multi-purpose Hydro-20 – 100 % model. Eight measurements were taken for each parameter at an interval of 8 hours at an elevation of 1.5m above the ground. Coordinates and elevation of the points were captured using a Garmin Handheld GPS. Data obtained were imported in compatible formats with ArcGIS 10.5 and the values for the un-sampled locations within the study area was determined through the interpolation of the collected data. A subset covering the study area was extracted for bands 1,2,3,4 and 5. Bands 1, 2 and 3 which are visible bands were used in generating a true colour composite image of the study area; the bands 4 and 5 which are not visible bands were used for the NDVI (Normalized Differential Vegetation Index). Result showed that Bende LGA had a vegetal cover of 45,741.26hectares out of a total of 60,152.76 hectares while Umuahia North had 19,689.09 hectares of vegetal cover out of a total of 24,459.75 hectares. Umuahia North had an average daily temperature of 31.309̊ C while Bende had 27.405̊ C. The average relative humidity in Bende LGA was 82.37% while Umuahia North was 67.274%. In conclusion, the study showed the existence of heat islands in the urban areas in Umuahia North LGA which was characterized by higher temperature but lower relative humidity. The heat island could be attributed to the gradual loss of vegetation cover and the increase in built-up environments in Umuahia North LGA.

Keywords: Land uses, soil depth, soil physical and chemical properties, watershed

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Impact of Land Use Types and Soil Depths on the Distribution of Soil Physical and Chemical Properties in Soils of Aboy Gara Watershed, at Gidan District, North Wollo Zone, Ethiopia

Gebeyaw, T. Y.

https://doi.org/10.36263/nijest.2019.02.0102

ABSTRACT
The study was conducted at the degraded land soils of the Abuhoy Gara Catchment, which is located in the Gidan District of North Wello Zone, Ethiopia to determine the impact of land use type and soil depth on the distribution of soil physical and chemical properties. Soil samples were collected from representative locations with four replications at two depths, surface (0-15 cm) and subsurface (15-30 cm) of cultivated, grazing and bush land use types. One hundred eighty soil samples were collected from the depths of 0-15 and 15-30 cm each in a radial sampling scheme using an auger. Totally, twelve composite soil samples were collected using flexible grid survey method of 1:30,000 scales. The collected samples were air-dried, homogenized and sieved to pass a 2 mm mesh sieve for the standard physical and chemical analyses. Results showed that the soil physical and chemical properties were significantly affected by the interaction of land uses and soil depths. Silt content decreases while clay content increases across depth from surface to subsurface soils. The lowest pH-H2O was registered at the subsurface soils of the grazing lands, while the highest was recorded at the surface soils of the bush land. The interaction effect of land use by soil depth on the variability of soil organic matter was significantly higher at surface layer of the grazing land and lower at surface layer of cultivated land. Similarly, soil total nitrogen was highest in surface layer of the grazing land, while it was lowest in subsurface layer of the bush land. Exchangeable bases were highest in surface soils of the bush land and lowest in the surface soils of cultivated land. The contents of both exchangeable bases were decreasing with soil depth in all land uses except the bush land. Significant difference in cation exchange capacity contents was observed as highest in surface soil layer of the bush land and lowest in surface soil layer of the cultivated land. From the results of the study, it can be concluded that the interaction of land use with soil depth showed negative effects especially disturbance of soil nutrient status on cultivated land in surface soils. In general, the spatial variability of soil properties indicates the soil conditions were strongly affected by inappropriate land use and soil management practices including soil depth. Therefore, reducing intensity of cultivation, adopting integrated soil fertility management and application of organic fertilizers could maintain the existing soil condition and replenish degraded soil properties.

Keywords: Land uses, soil depth, soil physical and chemical properties, watershed

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Implementation of Condition Equation Model in Geodetic Observation: A Case Study of Circular Reservoir Structure

Oladosu, S. O., Okonofua, S. E. and Ehigiator-Irughe, R.

https://doi.org/10.36263/nijest.2019.02.0120

ABSTRACT
In engineering projects involving the construction of above-ground storage tank big enough to retain and/or accommodate large quantities of petroleum products such as crude oil and condensate, mathematical reduction of obtained field data using condition equation method is always appropriate for an onward monitoring of those structures. This paper demonstrates how condition equation method can be used to adjust geodetic surveying measurements in relation to above-ground storage tank. Accuracy is in the order of σa = 5.66e-4 and σb = 1.113e-3 while σsmax and σsmin are 0.0522 and -0.0511 respectively. The results obtained revealed that the method can be satisfactorily implemented for above-ground circular reservoir storage tank structural modelling and monitoring for a similar scenario.

Keywords: Crude oil, Condition equation, Observation, Storage tank

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Finite Element Application in Reservoir Deformation analysis (Part 1)

Ehigiator-Irughe, R.

https://doi.org/10.36263/nijest.2019.02.0135

ABSTRACT
Finite element method (FEM) is a numerical technique for solving engineering problem and mathematical physics, useful problems with complicated geometries, loading, and material properties where analytical solutions may not be obtained. Some of the complicated problems involving load is a cylindrical reservoir structure where crude oil is stored in a tank farm. This paper demonstrates the use of Finite Element Analysis in above surface cylindrical reservoir engineering structure. The reservoir which has sixteen (16) monitoring station was monitored using reflectorless Total station. This paper is a pilot model and it is hoped to be developed further in two more phases to cover the entire reservoir under study. Only two studs in the North East and South East directions were selected to test the FEM forming a triangular shade (Truss) with three elements. The 2-D horizontal displacement was found to be 0.02 mm, while the vertical displacement was found to be -0.03 mm.

Keywords: Crude oil, Finite element, Reservoir, Stiffness matrix, Strain and stress analysis

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