scholarly journals Groundwater exploitation in Awka (Anambra – Nigeria) and environs: Prospects, and challenges while drilling and its mitigation measures

2021 ◽  
Vol 10 (4) ◽  
pp. 27-33
Author(s):  
Ifeanyi Emmanuel Anyanwu ◽  
Sodiq Solagbade Oguntade

Groundwater exploitation (borehole drilling) was carried out around Awka and environs in Anambra State, Southeastern Nigeria, to understand the underlying rock units encountered while drilling, differentiate boreholes with confined aquifers from those with unconfined aquifers, delineate the probable aquiferous zones from the borehole data, evaluate the challenges encountered while drilling (both geologic and technical), and identify mitigation measures employed to address these challenges. Detailed geologic log information of the boreholes was produced to illustrate the rock units encountered while drilling. Four rock units were identified, namely: shale, sandstone, clay, and gravel. These rock units were exposed within the Imo Formation and the Nanka Formation that underlie the study area. Results from the geologic log information of the boreholes indicate that the water table within the study area ranges from 11.2 m to 56.5 m from the soil surface, and the probable aquiferous zones vary from 6.8 m to 23.3 m in thickness. A detailed look at the lithologic logs of the boreholes show that 50% of the drilled boreholes possess confined aquifers while the remaining 50% have unconfined aquifers. A careful appraisal of the challenges encountered, which are mainly geologic, is strictly attributed to the geologic formation of the study area. Other technical challenges have been derived from mechanical faults developed during drilling.

2021 ◽  
Vol 61 (2) ◽  
pp. 389
Author(s):  
Rebecca Doble ◽  
Dirk Mallants ◽  
Yousef Beiraghdar Aghbelagh ◽  
Dennis Gonzalez ◽  
Phil Davies ◽  
...  

The Geological and Bioregional Assessment Program examines the potential impacts of shale, tight and deep coal gas development on water and the environment. A key part of the project was quantifying the potential for a decline in the water quality of unconfined aquifers due to unintentional chemical release at the soil surface. To assess this hazard, a quantitative analysis of chemical migration pathways was undertaken, which involved the estimation of contaminant attenuation by dilution and dispersion in soil and groundwater. This provided a conservative screening approach to identify areas for further analysis. Attenuation calculations involved one-dimensional advection-dispersion (AD) simulations through the unsaturated zone, and three-dimensional AD solute transport within the surficial aquifers. Dilution factor (DF) relationships for the combined effect of attenuation in the unsaturated and saturated zone were used to construct spatial maps of the potential for impact on aquifer properties after accidental chemical spills. A higher DF (therefore lower consequence of the surface contamination) was associated with deeper unsaturated zones characterized by heavier soils near the surface, and lower ground water velocities due to lower hydraulic conductivity and/or hydraulic gradient in the saturated zone. The framework was applied across the Cooper Basin and Beetaloo Sub-basin and resulted in two types of maps. The first identified areas being more susceptible to contamination if soil remediation does not occur within a 10-year period. The second map shows the spatially variable combined DFs for a ground water receptor, which may be used to develop site-specific management plans and mitigation measures.


2006 ◽  
Vol 41 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Nicolas Stämpfli ◽  
Chandra A. Madramootoo

Abstract Recent studies have shown subirrigation (SI) to be effective in reducing nitrate losses from agricultural tile drainage systems. A field study was conducted from 2001 to 2002 in southwestern Québec to evaluate the effect of SI on total dissolved phosphorus (TDP) losses in tile drainage. In an agricultural field with drains installed at a 1-m depth, a SI system with a design water table depth (WTD) of 0.6 m below the soil surface was compared with conventional free drainage (FD). Subirrigation increased drainage outflow volumes in the autumn, when drains were opened and water table control was interrupted for the winter in the SI plots. Outflows were otherwise similar for both treatments. Throughout the study, the TDP concentrations in tile drainage were significantly higher with SI than with FD for seven out of 17 of the sampling dates for which data could be analyzed statistically, and they were never found to be lower for plots under SI than for plots under FD. Of the seven dates for which the increase was significant, six fell in the period during which water table control was not implemented (27 September 2001 to 24 June 2002). Hence, it appears that SI tended to increase TDP concentrations compared with FD, and that it also had a residual effect between growing seasons. Almost one-third of all samples from the plots under SI exceeded Québec's surface water quality standard (0.03 mg TDP L-1), whereas concentrations in plots under FD were all below the standard. Possible causes of the increase in TDP concentrations in tile drainage with SI are high TDP concentrations found in the well water used for SI and a higher P solubility caused by the shallow water table.


Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 961
Author(s):  
Meryem Touzani ◽  
Ismail Mohsine ◽  
Jamila Ouardi ◽  
Ilias Kacimi ◽  
Moad Morarech ◽  
...  

The main landfill in the city of Rabat (Morocco) is based on sandy material containing the shallow Mio-Pliocene aquifer. The presence of a pollution plume is likely, but its extent is not known. Measurements of spontaneous potential (SP) from the soil surface were cross-referenced with direct measurements of the water table and leachates (pH, redox potential, electrical conductivity) according to the available accesses, as well as with an analysis of the landscape and the water table flows. With a few precautions during data acquisition on this resistive terrain, the results made it possible to separate the electrokinetic (~30%) and electrochemical (~70%) components responsible for the range of potentials observed (70 mV). The plume is detected in the hydrogeological downstream of the discharge, but is captured by the natural drainage network and does not extend further under the hills.


Author(s):  
Abdel-Rahman A. Abueladas ◽  
Tina M. Niemi ◽  
Abdallah Al-Zoubi ◽  
Gideon Tibor ◽  
Mor Kanari ◽  
...  

The cities of Aqaba, Jordan and Elat, Israel are vulnerable to seismic damage because they are built over the active faults of the Dead Sea Transform that are the source of historically destructive earthquakes. A liquefaction susceptibility map was generated for the Aqaba–Elat region. Borehole data from 149 locations and the water table depth were used to calculate effective overburden stress in the Seed–Idriss simplified method. The liquefaction analysis was based on applying a cyclic loading scenario with horizontal peak ground acceleration of 0.3 g in a major earthquake. The liquefaction map, compiled using a GIS platform, shows high and moderate liquefaction susceptibility zones along the northern coast of the Gulf of Aqaba that extend 800 m inland from the shoreline. In Aqaba, several hotels, luxury apartment complexes, archaeological sites, ports and commercial districts are located within high and moderate liquefaction zones. In Elat, the seaport and the coastal hotel district are located within a high susceptibility zone. Most residential areas, schools and hospitals in both cities are located within zones not susceptible to liquefaction based on the methods of this study. The total area with the potential to be liquefied along the Gulf of Aqaba is c. 10 km2. Given predictions for global sea-level, we ran three liquefaction models utilizing projected water table rises of 0.5, 1 and 2 m. These models yielded an increase in the area of high liquefaction ranging from 26 to 49%. Given the high potential of future earthquakes, our liquefaction susceptibility maps should help inform city officials for hazard mitigation planning.


1981 ◽  
Vol 97 (3) ◽  
pp. 557-568 ◽  
Author(s):  
R. K. Belford

SUMMARYThe response of winter wheat cv. Maris Huntsman to waterlogging was studied in two experiments in soil columns outdoors. Winter waterlogging treatments increased nodal root production and the proportion of aerenchyma within roots, but caused chlorosis and premature senescence of leaves, and decreased tillering. For all treatments, grain losses were much less than expected from the extent of tiller loss in winter; losses after single waterlogging events ranged from 2% (after 47 days with the water-table at 5 cm) to 16% (after 80 days with the water-table at the soil surface). Yield losses after three waterloggings at the seedling, tillering and stem elongation stages of growth were additive, and totalled 19%. In many treatments, grain loss was associated with lighter individual grain weights, suggesting that the size of the root system or efficiency of water and nutrient uptake by roots at the later stages of growth may have been less after earlier waterlogging. The importance of nitrogen fertilizer in maintaining a satisfactory plant nitrogen status was shown when nitrogen was with held before a 3-week waterlogging treatment during stem elongation; tiller and floret survival was subsequently greatly restricted and grain yields decreased 22% below those of plants waterlogged at the same stage of growth but supplied with nitrogen.


Author(s):  
Reem Ismail ◽  
Saeid Shafieiyoun ◽  
Riyadh Al Raoush ◽  
Fereidoun Rezanezhad

Most of the prediction theories regarding dissolution of organic contaminants in the subsurface systems have been proposed based on the static water conditions; and the influence of water fluctuations on mass removal requires further investigations. In this study, it was intended to investigate the effects of water table fluctuations on biogeochemical properties of the contaminated soil at the smear zone between the vadose zone and the groundwater table. An automated 60 cm soil column system was developed and connected to a hydrostatic equilibrium reservoir to impose the water regime by using a multi-channel pump. Four homogenized hydrocarbon contaminated soil columns were constructed and two of them were fully saturated and remained under static water conditions while another two columns were operated under water table fluctuations between the soil surface and 40 cm below it. The experiments were run for 150 days and relevant geochemical indicators as well as dissolved phase concentrations were analyzed at 30 and 50 cm below the soil surface in all columns. The results indicated significant difference in terms of biodegradation effectiveness between the smear zones exposed to static and water table fluctuation conditions. This presentation will provide an overview of the experimental approach, mass removal efficiency, and key findings.


2020 ◽  
Vol 1 (1) ◽  
pp. 181-186
Author(s):  
I Gusti Agung Gede Catra Artawan ◽  
I Nyoman Budiartha ◽  
I Nyoman Sutama

Underground water is water that is contained in a layer of soil or rock below the soil surface. This study aims to determine the government's authority in regulating groundwater permits and what are the legal consequences of violating unlicensed groundwater use. The research was conducted using empirical legal research methods, source of the data which was used are primary and secondary sources of legal materials, methods of collecting legal materials using documentation studies and field research, and analyzing legal materials using descriptive analysis methods. The results of this study indicate that the Government's authority in permitting groundwater is regulated in the Bali Governor Regulation Number 5 of 2016 concerning Groundwater Permits, particularly in Article 3 paragraph (1), it is explained that the Governor has the authority to manage groundwater in CAT in the province. In Article 3 paragraph (2), the authority of the Government (Governor) is reaffirmed, including several things, namely: granting permits for groundwater drilling; give permission to extract groundwater; grant permits for the use of groundwater; granting permits for groundwater exploitation; grant permits to groundwater drilling companies; provide guidance, supervise technical investigations and use of Groundwater. As a result of violations of the use of groundwater by violating the parties in accordance with Article 15 paragraph (1) of Law Number 11 of 1974 concerning Irrigation, it is stated that anyone who deliberately runs water and / or water sources business without permission from the Government is punishable by imprisonment. 2 (two) years and or a maximum fine of Rp. 5,000,000 (five million rupiah).


Irriga ◽  
2001 ◽  
Vol 6 (2) ◽  
pp. 62-68
Author(s):  
Marcos Henrique Sias Silveira ◽  
Antonio Evaldo Klar

PRODUÇÃO DE MATÉRIA SECA E EVAPOTRANSPIRAÇÃO REAL DA AVEIA PRETA (Avena strigosa S.) EM SEIS NÍVEIS FREÁTICOS  Marcos Henrique Dias SilveiraAntonio Evaldo KlarDepartamento de Engenharia Rural –  Faculdade de Ciências Agronômicas – UnespBotucatu – SP  Cep: 18603-970Fone: (0xx14) 6802-7165 – [email protected]  1  RESUMO Para avaliar os efeitos de seis diferentes níveis freáticos na produção de matéria seca e na evapotranspiração real ou de cultura da aveia preta (Avena strigosa S.) foi conduzido um experimento em casa de vegetação, no Departamento de Engenharia Rural da FCA - Campus de Botucatu - UNESP.  Foram semeadas 21 sementes de aveia por vaso, construído de anéis de PVC, com diâmetro nominal de 0,15m x 0,07m de comprimento e alturas totais variando entre 0,21m e 0,91m, de modo a simular os efeitos de níveis freáticos de 0,17m, 0,31m, 0,45m, 0,59m, 0,73m e 0,87m de profundidade.  Após a emergência das plântulas procedeu-se ao desbaste,  deixando-se 8 plantas por vaso, com 06 repetições (seis vasos) para cada nível freático, totalizando 36 vasos em delineamento inteiramente casualizado.  Dados de evapotranspiração real foram coletados diariamente e computados semanalmente.  As plantas foram cortadas rente ao solo ao final da 12.ª semana após a semeadura.  Foram avaliadas as produções de matéria seca da parte aérea e do sistema radicular em cada nível freático.  Os resultados mostraram maior produção de matéria seca para o nível freático mais superficial (0,17m), com queda gradativa à medida que o nível freático se aprofundava. A evapotranspiração da cultura  mostrou a mesma tendência, variando entre 591,6 mm  no tratamento com nível freático a 0,17m de profundidade e 215,4 mm para o de 0,87m de profundidade. UNITERMOS: evapotranspiração, níveis freáticos, aveia preta.  SILVEIRA, M. H. D., KLAR, A. E.  DRY MATTER PRODUCTION AND EVAPOTRANSPIRATION OF OAT         ( Avena strigosa S.) UNDER  SEVERAL TABLE LEVELS.  2  ABSTRACT The aim of this study was to evaluate the influence of six different water table levels on yield and evapotranspiration of oat (Avena strigosa S.) .  21 seeds were sowed  per  pot, which was built with PVC rings (0.15m nominal diameter x 0.07m lenght).  6 water table levels were used: 0.17; 0.31; 0.45; 0.59; 0.73; and 0.87 m measured from the soil surface replicated  6  times.  The completely randomised design was used.  After seedling emergency, 8 plants were maintained  per  pot.  The evapotranspiration were daily measured from reservoirs connected to the pots.  The plants were cut at the soil surface level after 12 weeks from the sowing.The results showed greater dry matter production at the most superficial water table level with progressive decrease with water level distance from the soil surface.  The  evapotranspiration  showed  the  same tendency: the higher values occurred on the 0.17m water table (591.6 mm) until 0.87m water table (215.4 mm). KEYWORDS:  water table, evapotranspiration, Avena strigosa S.


Agro-Science ◽  
2020 ◽  
Vol 19 (3) ◽  
pp. 51-61
Author(s):  
F.C. Okenmuo ◽  
C.O. Anochie ◽  
M.E. Ukabiala ◽  
C.L.A. Asadu ◽  
P.K. Kefas ◽  
...  

The soils of Atani floodplain in Anambra State of Nigeria contribute significantly to the food production of the State, hence the need to understand their behavior in order to enhance their management and productivity. Profile pits were sited along three physiographic units viz: levee crest, levee  slope and flood basin. Soil samples were collected from the profile horizons and subjected to standard laboratory procedures. Characterization of the soils was based on their morphological, physical and chemical properties. Soil classification was carried out using the USDA Soil Taxonomy and correlated with FAO/IUSS World Reference Base. Its agricultural potential was assessed using the fertility capability classification. The soils were deep. Topsoil colour was dominantly blackish black (10YR 3/2). Mottles were pervasive; an indication of impeded drainage conditions. The soils were predominantly fine textured. Soil pH values ranged from 4.8 to 6.2. Exchangeable Calcium was low to moderate (2.6-8.2 cmol kg−1); Magnesium was moderate to high (1.6-6.8 cmol kg−1); Sodium was high to very high (1.0-2.5 cmol kg−1), while potassium was high (1.2-4.2 cmol kg−1). Cation  exchange capacity values ranged from 11.6 to 42.6 cmol kg−1. Total nitrogen was very low to low (0.14-1.12 g kg−1), while organic carbon was low to moderate (0.4-15.2 g kg−1). Available phosphorus was very low to high ranging from 0.93 to 31.71 mg kg−1 while base saturation ranged from 64 to 93%. The soils were classified as Typic Fluvaquents (Typic Fluvisols), Fluvaquentic Endoaquepts (Endostagnic Cambisols) and Fluventic Endoaquepts (Endostagnic Cambisols) according to the USDA and FAO/IUSS. The fertility capability evaluation of the soils revealed that the pedons were Lgn in classification due to limitations in drainage. Key words: alluvium, cambic horizon, Inceptisols, lithologic discontinuity


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