Výsledky vyhľadávania

Nájdených záznamov: 2  
Vaša požiadavka: Autor-kód záznamu = "^umb_un_auth 0295701^"
  1. NázovDirect detection of groundwater accumulation zones in saprock aquifers in tectono-thermal environments
    Aut.údajeAnthony E. Akpan ... [et al.]
    Autor Akpan Anthony E. (20%)
    Spoluautori Ekwok Stephen Eguba (10%)
    Ben Ubong Camilus (5%)
    Ebong Ebong Dickson (5%)
    Thomas Jewel Emem (5%)
    Ekanem Aniekam Martin (5%)
    George Nyaknno J. (5%)
    Abdelrahman Kamal (5%)
    Fnais Mohammed S. (5%)
    Eldosouky Ahmed M. (5%)
    Andráš Peter 1953- (20%) UMBFP01 - Katedra geografie a geológie
    Alarifi Saad S. (10%)
    Zdroj.dok. Water. Vol. 15, no 22 (2023), pp. 1-21. - Basel : Multidisciplinary Digital Publishing Institute, 2023
    Kľúč.slová podzemné vody   podzemné termálne vody   saprockové vodonosné vrstvy - saprock aquifers  
    Form.deskr.články - journal articles
    Jazyk dok.angličtina
    KrajinaŠvajčiarsko
    AnotáciaVES data acquired in tectono-thermally disturbed environments sometimes contain outliers when plotted on a bi-logarithmic graph. These noisy datasets usually distort the discernible trend of the VES curve, by plotting abnormally above or below its dominant trend at the point of their occurrence. This type of distortion is different from those arising from other causes such as galvanic and static distortions, which usually affect a segment of a curve without changing the curve’s trend. Allowing these unusual points to remain within the datasets during the data processing and modelling phases always produces unsatisfactory results because their presence usually causes the root-mean-square error to exceed the preset acceptable limit. Consequently, such data points are usually deleted to recover the trend of the curve and generate interpretable models during the traditional curve-smoothening (data processing) phase. This study has shown that these unusual data points are indicative of groundwater accumulation zones in porous medium and can also estimate likely borehole productivities in tectono-thermally disturbed environments. A single-point drop signifies a low-yielding fracture characterized by small apertures. The groundwater yield from this group of fractures can barely support the daily domestic water needs of some families. However, VES curves where two or more points break away from the trend of the curve indicate high-yielding fractures or nonconformities, provided that the resistivity value of the first break-point is lower than those of subsequent ones. The productivity level of this category of fractures is high enough to support the water needs of families. The apparent resistivities of these saturated fractures usually vary between 40 and 500 Wm, depending on the nature of the host rock. These qualitative interpretations have been confirmed by drilling and Water 2023, 15, 3946 17 of 21 pumping test results. Depths to these water-filled fractures, though location-dependent, typically vary between 40 and 100 m in the study area. These saturated fractures are common in locations with high lineament density. Optimal data-quality-management practices—including determining the sensitivity level of the equipment, repeating the measuring process, and changing the potential electrode positions and, where possible, the VES profile orientation—must be implemented to confirm the integrity and subterranean nature of the break-off points.
    URLLink na plný text
    Kategória publikačnej činnosti ADC
    Číslo archívnej kópie53990
    Katal.org.BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici
    Báza dátxpca - PUBLIKAČNÁ ČINNOSŤ
    OdkazyPERIODIKÁ-Súborný záznam periodika
    článok

    článok

  2. NázovTowards understanding the extent of saltwater incursion into the coastal aquifers of Akwa Ibom State, Southern Nigeria using 2D ERT
    Aut.údajeStephen E. Ekwok ... [et al.]
    Autor Ekwok Stephen Eguba (30%)
    Spoluautori Ben Ubong Camilus (10%)
    Eldosouky Ahmed M. (10%)
    Qaysi Saleh (5%)
    Abdelrahman Kamal (10%)
    Akpan Anthony E. (10%)
    Andráš Peter 1953- (25%) UMBFP04 - Katedra životného prostredia
    Zdroj.dok. Journal of King Saud University - Science. Vol. 34, no. 8 (2022), pp. [1-8]. - Amsterdam : Elsevier B.V., 2022
    Kľúč.slová slané vody   pobrežia  
    Heslá geogr. Nigéria
    Form.deskr.články - journal articles
    Jazyk dok.angličtina
    KrajinaVeľká Británia
    AnotáciaThe hydro-lithostratigraphic units of the coastal area of Akwa Ibom State, Southern Nigeria were investigated involving electrical resistivity tomography (ERT) and Wenner array. This procedure and electrode configuration were adopted because of their wide range of sensitivity and inherent characteristics to geological materials. This study is aimed at defining the extent of saltwater invasions into the coastal and inland aquifers. The investigated area is divided into three zones A ( 0 < 20 km), B (<20 < 40 km), and C (>40 km)) based on the distance from the survey locations to the shoreline. The saline aquifer of the control tomogram obtained at the shoreline (Ibeno Beach) is characterized by the electrical resistivity of 0.159–3.55 Om. Within Zone A, (Ukpenekang, Eastern Obolo, and Okoro Ette), the saline aquifer is defined by electrical resistivity values of 0.33–44.0 Om, 2.07–48.5 Om, and 8.0–60.0 Om respectively. In general, the Zone B saline aquifers are defined by electrical resistivity values of 0.602–64.5 Om. Furthermore, the third zone which is situated a distance >40 km from the shoreline, is described by relatively higher electrical resistivity values (38.9–3260 Om) and indicates a region free from saltwater incursions. Generally, the 2D ERT models showed that electrically resistivity values increase progressively inland.
    URLLink na plný text
    Kategória publikačnej činnosti ADM
    Číslo archívnej kópie52293
    Katal.org.BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici
    Báza dátxpca - PUBLIKAČNÁ ČINNOSŤ
    OdkazyPERIODIKÁ-Súborný záznam periodika
    článok

    článok



  Tieto stránky využívajú súbory cookies, ktoré uľahčujú ich prezeranie. Ďalšie informácie o tom ako používame cookies.