Contribution of Soil Physical Propreties in The Assessment of Flood Risks in Tropical Areas. Case of The Mbo Plain

Author(s):  
Sylvie Noelle DJUKEM FENGUIA ◽  
David Guimolaire Nkouathio

Abstract Flooding occurs when water is in excess and can no longer be evacuated normally. The nature of the soil has been identified as one of the major causes of flooding, hence this study aimed is to show the influence of the physico-chemical properties of the soil on the recurrence of flooding in the Mbo plain. Four soil profiles were carried out on the alluviums according to the altitudes. These profiles were described and undisturbed soil samples were taken. Then, measurements of the infiltration rate of water in the soil by the Porchet method were carried out in sixteen sites. Finally, soil samples taken by auger and core sampling were studied in the laboratory. Physico-chemical parameters such as grain size, porosity, moisture, pH, compactness and organic matter were determined. Infiltration tests carried out in situ using the Porchet method revealed a hydraulic conductivity between 10−5 and 10−7 m/s, characteristic of a semi-permeable soil. This low value of permeability results from the morpho-structural arrangement and the chemical composition of the soils of the plain. These soils are hydromorphic, which means that they are constantly flooded and temporarily waterlogged. They are more or less sandy-clay on the surface, and very clayey at depth, generally from 25 cm. The very clayey soils at the base considerably slow down infiltration and act as a real barrier layer that prevents water from infiltrating, resulting to intense runoff. These soils are very porous and compact with a fairly high water content of up to 71%. This work allows us to conclude on the role of intrinsic soil properties on the genesis of floods in lowland areas. As in many plains in Africa and in the world, the nature of the soil in the Mbo plain is a natural predisposing factor to flood risks. The methods used can be applied in areas with the same characteristics as the Mbo Plain.

2021 ◽  
Author(s):  
Birtukan Amare Kebede ◽  
Eyayu Fetene Molla ◽  
Yihenew G.Selassie Mengesha ◽  
Habtamu Tadele Belay ◽  
Tesfaye Bayu Zeleke

Abstract Background: Understanding the soil reaction (pH) is relevant for improving crop productivity. Soil acidity is one of the restraining factors to crop production in the highlands of Ethiopia. This study was carried out on the nitisols of Burie District to examine the effect of integrated use of Calcite and Nitrogen fertilizer on soil physico-chemical properties. Treatments were two levels of lime (0 and 0. 50 t ha-1) and five-level of nitrogen (0,100, 200, 300, and 400 kg ha-1). The experiment was laid out in randomized complete block design (RCBD) with ten treatments replicated three times. Before and after harvest, both disturbed and undisturbed soil samples were collected. Analysis of variance (ANOVA) and bivariate correlations was employed using SAS statistical package program version 9.0. After harvesting thirty soil samples were collected from each treatment and then ten composite soil samples within a block were arranged for laboratory analysis. Result: The result indicated that among the soil properties before planting the crop soil bulk density (BD), pH, organic carbon (OC), total nitrogen (TN), available P and CEC were 1.43g cm-3, 5.2 (strongly acidic), 1.32% (very low), 0.12% (low), 8.86 mg kg-1 (very low), and 19.57 cmolc kg-1 (medium), respectively. After harvesting, most of the surface physico-chemical properties except bulk density increased. The lowest soil BD was 1.21 g m-3 from plots treated with 0.5 t ha-1 lime and 400 kg ha-1 urea. The maximum soil pH (6.85) was obtained from plots treated with 400 kg ha-1 N and 0.5 t ha-1 lime. The maximum soil CEC (35.38 (cmolc kg-1) was obtained from plots treated with 400 kg ha-1 N and 0.5 t ha-1 lime. Level of lime, nitrogen fertilizer and interaction effects of lime and nitrogen fertilizer (L*N) significantly affected maize yield (p<0.001). Yield of maize have positive correlations with most soil physico-chemical properties but negative with BD (r=-0.543).The adjusted yield and net benefit was 6,410.20 kg ha-1 and 58,891.47 Ethiopian Birr (ETB), respectively.Conclusion: Inherent physicochemical properties of the soil is changed either by sole or combined use of lime and N fertilizer. Soils tilled with 0.5 t ha-1 lime and 138 kg ha-1 nitrogen was found in maximum net benefit. Residual long-term effects should be researched. Thus, liming should be given emphasis in acidic soil amelioration. Moreover, the government may facilitate the supply of calcite (CaCO3) and urea fertilizer to the farmers.


2019 ◽  
Vol 12 (04) ◽  
pp. 2011-2017
Author(s):  
Mohd Hafiz Mail ◽  
Nurhidayah Ab. Rahim ◽  
Azimah Amanah ◽  
Muhammad Hidhir Khawory ◽  
Mohd Anuar Shahudin ◽  
...  

Honey is at high risk for the adulteration in global trade. Studies on the authenticity of stingless bee honey from Trigona spp. is necessary since the market demand for this product is increasing, particularly in Malaysia, due to its high nutritional value. FTIR spectroscopy has recently been used approach for a rapid and non-destructive measurement of honey quality and discriminate adulterated honey. The purpose of this study is to determine the FTIR and elementary content of Trigona spp. and Apis spp. honey, and further investigate the influence of the additional adulterants to the measured spectra absorbance. Both Trigona spp. and Apis spp. honey exhibit almost identical IR spectra curves, but there are notable different of their absorbance peak at the identified functional group regions. There is a correlation of the measured absorbance to the actual composition of Trigona spp. honey, which emphasized the low carbohydrate but high water content of the honey. Water or vinegar diluted honey has segregated absorbance peak from the pure honey. Our finding indicated that the FTIR is applicable in discriminate of pure and adulterated Trigona honey, but a further investigation on physico-chemical properties such as elementary content is needed for a comprehensive analysis.


2021 ◽  
Vol 11 (5) ◽  
Author(s):  
Fethi Medjani ◽  
Mohamed Djidel ◽  
Sofiane Labar ◽  
Louiza Bouchagoura ◽  
Chouaib Rezzag Bara

AbstractShallow aquifers are vulnerable to natural geogenic processes as well as anthropogenic influences, and this is especially apparent in desert regions. Within arid and hyperarid climates, evaporation is a controlling hydrologic process leads to an important increase in the concentration of dissolved minerals of both surface water and groundwater. In groundwater, this increase is not only dependent on shallow water table depth, but also on the hydraulic properties of sediments present within the unsaturated zone of the aquifer itself. The main objective of this research is to investigate possible mechanisms that might influence water quality changes under seasonal conditions in shallow aquifers situated within the Saharan desert region of Algeria. In this work, we focus on observed changes in hydrogeochemical characteristics, and the possible responsible processes. Under arid conditions, high water mineralization results in hypersaline water or brine solution formation within shallow aquifers. Due to active physico-chemical mechanisms such as Na+/Ca2+ ion exchange, the successive precipitation of calcite, gypsum, mirabilite or blœdite and halite is induced. Biological processes were also observed as prevalent; evidenced by large measured variations in CO2 load concentrations. These processes contributed to an inverse relationship between CO2 and O2 concentrations within the shallow aquifers studied.


2020 ◽  
Vol 5 (2) ◽  
pp. 65-71
Author(s):  
Israt Jahan ◽  
AKM Abul Ahsan ◽  
MMR Jahangir ◽  
Mahmud Hossain ◽  
Md Anwarul Abedin

Soil physico-chemical properties are an important phenomenon for sustainable crop production and maintenance of optimum soil health. Hence, a laboratory measurement was conducted with soil samples of three years long experimental field of the Department of Soil Science, Bangladesh Agricultural University, Mymensingh to assess the changes in five selected soil physico-chemical properties viz. soil texture, bulk density, soil pH, total nitrogen and organic matter. The experiment was laid out in a split plot design with two water regimes (continuous flooding and alternate wetting & drying) in the main plots and five fertilizer treatments (N0 - control, N1- 140 kg N/ha as PU, N2- 104 kg N/ha as USG (2× 1.8 g/ 4 hills), N3 - 5 t CD + PU @ 140 kg N /ha on IPNS basis and N4- 5 t CD + USG (2× 1.8 g/ 4 hills @ 104 kg N/ha)) in the subplots under rice-rice cropping pattern with three replications. After three years, soil samples were collected at 0-5 and 5-10 cm soil depths for measuring bulk density and at 0-10 cm depth for other soil properties and analyzed. Results found that % sand, % silt, % clay, bulk density and soil pH was not changed significantly compared to initial status. Percentage of total nitrogen and organic matter was significantly affected by irrigation and fertilization. Total nitrogen (%) was higher in AWD whereas organic matter (%) was higher in CF practice. The highest total nitrogen (%) and organic matter (%) was found in N4 treatment in which USG was applied in combination with cowdung as organic manure. It can be suggested that N4 treatment was formed good combination for sustaining chemical properties of soil. Further long- term experimentation will be needed to know the changes in soil properties for sustainable crop production and improving soil health. Asian Australas. J. Biosci. Biotechnol. 2020, 5 (2), 65-71


Author(s):  
J. M. Madu ◽  
A. I. Ogbonna ◽  
C. I. C. Ogbonna

Aim: Bioremediation of soil play a critical role in removing pollutants from crude oil polluted soil. To investigate the mycoflora of crude oil polluted area of Ukwa West Local Government in the present Abia State. Methodology: Portions of the soil samples collected from three (3) locations were plated out separately on Yeast Starch Agar, Starch Agar, and Cellulose Agar using soil plate methods. The culture plates were examined after 5-7 and 14 days for the presence of fungi. Pure cultures of the isolates were obtained by subculturing and the physico-chemical properties of the soil samples were determined using standard methods. Results: Twenty species (20) of fungi were isolated from the crude oil polluted soil sample and represented by their respective genera. Eight (8) species of Aspergillus representing 40%, two (2) species of Thermomyces representing 10% each, and one (1) species of Penicillium, Cladosporium, Cunninghamella, Curvularia, Trichoderma, Scopulariopsis, Sporotrichum and Basipetospora representing 5% each. Aspergillus species were predominant which include among others A. fumigatus, A. niger, A. parasiticus, A. oryzae, A. terreus. The physico-chemical properties of the soil sample were found to be varied and have affected the distribution and population of fungi. The pH values ranged from 4.81- 5.58 as compared to the control ranging from 5.72- 6.50 for soil samples A, B and C. The moisture content values ranged between 26.46-29.59% as compared to the control ranging from 29.41-32.51%. The soil was found to be high in organic matter content with values of 70.3-82.7% as compared to the control which was 94% for each of the locations. Conclusion: Crude oil polluted soils of Ukwa West of Abia State, Nigeria is rich in fungal biodiversity with the soil’s samples having different physico-chemical properties.


Author(s):  
Z. Abdulhamid ◽  
E.B. Agbaji ◽  
C.E. Gimba ◽  
A.S. Agbaji

Physico-chemical properties and heavy metals content of soils were determined from seven farms in Minna, central Nigeria. Conventional analytical methods were employed to determine the physico-chemical properties and the heavy metals were analysed by atomic absorption spectrometry. The result showed that pH values ranged from 6.64 - 7.70 indicating slight acidity to slight alkalinity of the soils. The total organic carbon values ranged from 0.95-2.25 % resulting in the presence of organic matter (1.63-3.87). The electrical conductivity values ranged from 17-37 μS/cm. The cation exchange capacity of the soil samples ranged from 3.68-5.15 cmol/kg. The heavy metals levels were in the following range: Cd (0.00018-0.00134 mg/g), Cu (0.0069-0.0476 mg/g), Fe (1.942-2.2059 mg/g), Mn (0.1825-0.3696 mg/g), Ni (0.0065-0.0069 mg/g) and Zn (0.0157-0.2252 mg/g). The concentration of the metals in the soil samples varied according to the following trend: Fe>Mn>Zn> Cu>Ni>Cd. The average concentration of all the metals in each farm also gave the trend Farm B>Farm G>Farm E>Farm C>Farm F>Farm D>Farm A. The findings indicate the presence of heavy metals in all the farms but only Fe was above the FAO/WHO standards.


Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7981
Author(s):  
Roxana P. F. de Sousa ◽  
Glauco S. Braga ◽  
Raphael R. da Silva ◽  
Giovanna L. R. Leal ◽  
Júlio C. O. Freitas ◽  
...  

This work has developed and evaluated a microemulsion-based drilling fluid formulation with characteristics to be applied in oil wells. The microemulsion was formulated with a solution of water/glycerol, pine oil, and Tween 80, a nonionic and biodegradable surfactant. The physical and chemical properties of the drilling fluid obtained in this work were investigated through rheology and filtration analysis, solids content, aging, lubricity, toxicity, and thermal degradation. A non-toxic microemulsion-based drilling fluid oil-in-water (O/W) with high lubricity (0.07638) and thermal stability was obtained with suitable viscosity, gel strength and low fluid loss (4.0 mL), low solids content (6%), stability in a wide range of salinity conditions, and the possibility of high water content (above 85% in mass fraction). The fluid presented a pseudoplastic behavior, and statistically significant Herschel–Bulkley parameters were obtained.


2019 ◽  
Vol 32 (1) ◽  
pp. 1-8
Author(s):  
N. Sharma ◽  
T. Sinderpal

Physico-chemical properties are crucial characteristics of hydrocolloids as they decide the applicability of them. Rheology of system, flow behaviour and mechanical properties make hydrocolloids suitable for food industry. Modification of consistency or texture properties of functional polymers also controls their sensory characteristics, thereby they become significant essences such as thickener, gelling agents, foaming agent, texture modifier, viscosifier, emulsifier, stabilizer and binder. Industrial and pharmaceutical applications are also controlled by some suitable physico-chemical properties of hydrocolloids. The polysaccharide gum exudates constitute a architecturally distinct class of complex biomacromolecules having unique physico-chemical properties. Due to their good bio/tissue compatibility, non-toxicity, they are extensively used in the field of tissue engineering, drug delivery and wound healing. Chemical and molecular architecture of hydrocolloids in turn controls their physico-chemical and functional properties. Sterculia gum is a substituted rhamnogalacturonoglycan (pectic) type exudate gum used as suspending agent, gelling agents, emulsifier, bulk laxative, dental adhesive, drug delivery agent and wound healing agent. It exhibits high water retention capacity, high viscosity and least solubility. Solutions of sterculia gum are viscoelastic and thixotropic. Sterculia gum has been recommended as effective wound dressing material as it can form a intensely adhesive gel when dispersed in minimum ammount of water. Owing to wide applications and distinctive properties of sterculia gum, present work is an endeavor to summarize the molecular organization, chemical configuration and physico-chemical properties of sterculia gum and the factors affecting physico-chemical properties of sterculia gum.


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