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Effective public policies are needed to manage a nation’s natural resources, including soil and water. However, making such policies currently requires a shift from a traditional qualitative approach to a mix of scientific data, evidence and the relevant social elements, termed data-driven policymaking. Nigeria, like most developing countries, falls short of the framework for this approach. Nevertheless, the lack of potable water in some regions and the continuous degradation of farmable lands call for intervention through effective policy formulation and implementation. In this work, we present a conceptual workflow as a strategic step towards developing a framework for a data-driven soil and water resources management policy. A review of the current legal and policy framework and selected scientific literature on soil and water resources in Nigeria is presented. Analysis of the National Water Resources Bill proposed in 2018 is used to highlight existing gaps between policy, scientific data and reality. Modern field techniques and project-based examples for soil and aquifer characterization that can be adapted for local use are presented. While government must take responsibility for the poor policy framework, the research community is challenged on the need for scientific data as a base for effective policy formulation and implementation.
Kennedy Doro; Solomon Ehosioke; Ahzegbobor Aizebeokhai. Sustainable Soil and Water Resources Management in Nigeria: The Need for a Data-Driven Policy Approach. Sustainability 2020, 12, 1 .
AMA StyleKennedy Doro, Solomon Ehosioke, Ahzegbobor Aizebeokhai. Sustainable Soil and Water Resources Management in Nigeria: The Need for a Data-Driven Policy Approach. Sustainability. 2020; 12 (10):1.
Chicago/Turabian StyleKennedy Doro; Solomon Ehosioke; Ahzegbobor Aizebeokhai. 2020. "Sustainable Soil and Water Resources Management in Nigeria: The Need for a Data-Driven Policy Approach." Sustainability 12, no. 10: 1.
Thorough knowledge of root system functioning is essential to understand the feedback loops between plants, soil, and climate. In situ characterization of root systems is challenging due to the inaccessibility of roots and the complexity of root zone processes. Electrical methods have been proposed to overcome these difficulties. Electrical conduction and polarization occur in and around roots, but the mechanisms are not yet fully understood. We review the potential and limitations of low‐frequency electrical techniques for root zone investigation, discuss the mechanisms behind electrical conduction and polarization in the soil–root continuum, and address knowledge gaps. A range of electrical methods for root investigation is available. Reported methods using current injection in the plant stem to assess the extension of the root system lack robustness. Multi‐electrode measurements are increasingly used to quantify root zone processes through soil moisture changes. They often neglect the influence of root biomass on the electrical signal, probably because it is yet to be well understood. Recent research highlights the potential of frequency‐dependent impedance measurements. These methods target both surface and volumetric properties by activating and quantifying polarization mechanisms occurring at the root segment and cell scale at specific frequencies. The spectroscopic approach opens up a range of applications. Nevertheless, understanding electrical signatures at the field scale requires significant understanding of small‐scale polarization and conduction mechanisms. Improved mechanistic soil–root electrical models, validated with small‐scale electrical measurements on root systems, are necessary to make further progress in ramping up the precision and accuracy of multi‐electrode tomographic techniques for root zone investigation.
Solomon Ehosioke; Frédéric Nguyen; Sathyanarayan Rao; Thomas Kremer; Edmundo Placencia‐Gomez; Johan Alexander Huisman; Andreas Kemna; Mathieu Javaux; Sarah Garré. Sensing the electrical properties of roots: A review. Vadose Zone Journal 2020, 19, 1 .
AMA StyleSolomon Ehosioke, Frédéric Nguyen, Sathyanarayan Rao, Thomas Kremer, Edmundo Placencia‐Gomez, Johan Alexander Huisman, Andreas Kemna, Mathieu Javaux, Sarah Garré. Sensing the electrical properties of roots: A review. Vadose Zone Journal. 2020; 19 (1):1.
Chicago/Turabian StyleSolomon Ehosioke; Frédéric Nguyen; Sathyanarayan Rao; Thomas Kremer; Edmundo Placencia‐Gomez; Johan Alexander Huisman; Andreas Kemna; Mathieu Javaux; Sarah Garré. 2020. "Sensing the electrical properties of roots: A review." Vadose Zone Journal 19, no. 1: 1.
Seismic borehole tomography has become a standard method and is routinely used for the detection of karstic phenomena and the delineation of geological structures. Seismic tomography is believed to be the seismic method promising highest accuracy and reliability. Remaining uncertainties due to a non-zero residual travel time fit during data inversion are often neglected. However, data quality has a significant influence on the accuracy of a travel time pick. We present tomographic inversion results where the signal-to-noise ratio of the first arrival times is considered as a data quality measure during tomographic inversion. This new data quality weighting scheme is supposed to provide more reliable inversion results. Information about the reliability of the tomogram provided along with the seismic tomogram may support the geophysicist interpretation. The effect of the data quality weighted inversion is studied on a field data set.
Thomas Fechner; Solomon Ehosioke; Sonja Mackens; Lutz Karl; Daryl Tweeton. Reliability maps for seismic tomography. International Conference on Engineering Geophysics, Al Ain, United Arab Emirates, 15-18 November 2015 2015, 1 .
AMA StyleThomas Fechner, Solomon Ehosioke, Sonja Mackens, Lutz Karl, Daryl Tweeton. Reliability maps for seismic tomography. International Conference on Engineering Geophysics, Al Ain, United Arab Emirates, 15-18 November 2015. 2015; ():1.
Chicago/Turabian StyleThomas Fechner; Solomon Ehosioke; Sonja Mackens; Lutz Karl; Daryl Tweeton. 2015. "Reliability maps for seismic tomography." International Conference on Engineering Geophysics, Al Ain, United Arab Emirates, 15-18 November 2015 , no. : 1.
Detailed characterization of subsurface geological heterogeneities which control fluid flow and transport is still an unresolved challenge in the geoscience community. While surface geophysical methods have helped in obtaining large scale parameter distributions, the decrease of resolution with depth limits their application for delineating heterogeneities at high resolution. This limitation has encouraged the use of cross-hole geophysical techniques such as cross-hole seismic tomography. Cross-hole seismic tomography which involves measuring travel times of seismic ray paths between two or more boreholes in order to derive an image of seismic velocities between the wells offers an approach for characterizing geological heterogeneities at a high resolution. Its application range from near surface aquifer studies, geothermal, to deep oil and gas reservoirs (Sainkov et al 2005; Tselentis et al 2011). Becht et al., (2007), evaluated the use of cross-hole seismic tomography for high resolution aquifer characterization. In this study, we present a case application of cross-hole seismic tomography for a high resolution characterization of the Prakla-Seismos field test site. Detailed velocity distributions are correlated with available borehole geological data to better delineate subsurface heterogeneity which provide useful information for an improved groundwater flow and contaminant transport modeling in the area.
S.I Ehosioke; T. Fechner. Application of Cross-hole Seismic Tomography in Characterization of Heterogeneous Aquifers. Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics 2014, 1 .
AMA StyleS.I Ehosioke, T. Fechner. Application of Cross-hole Seismic Tomography in Characterization of Heterogeneous Aquifers. Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics. 2014; ():1.
Chicago/Turabian StyleS.I Ehosioke; T. Fechner. 2014. "Application of Cross-hole Seismic Tomography in Characterization of Heterogeneous Aquifers." Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics , no. : 1.