Groundwater Characterization and Ecological Assessment: A Case Study of Lagos State University, Ojo, Lagos
Majolagbe Abdulrafiu Olaiwola,
Yusuf Kafeelah Abosede,
Tovide Oluwakemi Omotunde,
Alegbe Monday John,
Tiamiyu Yusuf Ademola
Issue:
Volume 11, Issue 1, March 2023
Pages:
1-10
Received:
17 January 2023
Accepted:
6 February 2023
Published:
16 February 2023
Abstract: The only source of water supply in Lagos State University Ojo, Lagos State is sub surface water. Despite being under possible threats (natural and anthropogenic), the water is used for irrigation, domestic, recreation and drinking purposes, hence the need for quality verification so as to be sure of the safety of man. Therefore, this study sought the physicochemical quality assessment of groundwater in Lagos State University, main campus, employing standard procedures of American Public Health Association. Groundwater samples collected bimonthly from twenty five (25) wells were chemically investigated for pH, acidity, alkalinity, electrical conductivity, total dissolved solids, total hardness, anions and trace metals. Groundwater data generated from chemical laboratory were subjected to factor and cluster analyses. Six principal components (PCs) extracted 79.3 % of the total variance and five clusters of wells with distinct characteristics were also revealed. The order of exceedance of some quality parameters above WHO limits was NO32- > Mg > Fe > SO42- >TH, raising the question of safety on its potability. The sodium adsorption ratio (SAR), however showed that over 95% of the water samples analyzed are fit for irrigation purposes, thus portends safety for human health. The impact of agricultural activities among others are apparent on the quality of groundwater, hence the need for regular monitoring by relevant agency, in order to safeguard the safety of man and ensure sustainability of the environment.
Abstract: The only source of water supply in Lagos State University Ojo, Lagos State is sub surface water. Despite being under possible threats (natural and anthropogenic), the water is used for irrigation, domestic, recreation and drinking purposes, hence the need for quality verification so as to be sure of the safety of man. Therefore, this study sought t...
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Prerequisite Condition of Diffuse Attenuation Coefficient Kd(490) for Detecting Seafloor from ICESat-2 Geolocated Photons During Shallow Water Bathymetry
Dandabathula Giribabu,
Rohit Hari,
Jayant Sharma,
Aryan Sharma,
Koushik Ghosh,
Apurba Kumar Bera,
Sushil Kumar Srivastav
Issue:
Volume 11, Issue 1, March 2023
Pages:
11-22
Received:
9 April 2023
Accepted:
23 April 2023
Published:
17 May 2023
Abstract: Bathymetry refers to the depth measurement of the topographic seafloor surface and is essential geophysical data for understanding the land-ocean interplay. Recently, researchers have taken advantage of photon penetration of the green laser of NASA ICESat-2 to profile the seafloor as a part of the bathymetric mapping of shallow nearshore coastal waters. Prerequisite conditions for using the ICESat-2 geolocated photons for reconstructing the bathymetric profiles include a preference for using nighttime acquisitions followed by applying refraction correction to the water column returned photons to correct the apparent depths due to the change in the speed of light that occurs at the air-water interface. The success of detecting the seafloor from the bathymetric profiles from ICESat-2 photons will depend on the optical clarity of the water. The diffuse attenuation coefficient for downwelling irradiance, Kd(490), measures how light dissipates with depth in water and indicates how strongly light intensity at 490 nm of wavelength is attenuated in the water column, providing a hint about the water clarity. In this research, we have explored ICESat-2's photon-based bathymetric mapping potential in relation to the Kd(490). ICESat-2 photon data and Kd(490) data from level-2 OLCI of Sentinel-3 A/B mission were acquired with overlapping dates to investigate the possible depth penetration of ICESat-2 photons in the shallow waters during clear water conditions and sediment load periods. Two nearshore study sites were chosen that are located at the head of the Bay of Bengal. This research proves that the ICESat-2 photons can successfully reflect from the seafloor in shallow waters while the optical water condition is clear, during which the Kd(490) is less than 0.12 m-1. On the contrary, during the periods of sediment load in the water, where the Kd(490) is above 0.15 m-1, the ray tracing mechanism of ICESat-2 photons has been impacted due to absorption and scattering caused by the sediments load in the water column; thus, seafloor detection by ICESat-2 photons will not be successful in sediment loaded waters. The results from this research suggest the necessity of Kd(490) to be complementary data with ICESat-2 photons for successful bathymetric applications.
Abstract: Bathymetry refers to the depth measurement of the topographic seafloor surface and is essential geophysical data for understanding the land-ocean interplay. Recently, researchers have taken advantage of photon penetration of the green laser of NASA ICESat-2 to profile the seafloor as a part of the bathymetric mapping of shallow nearshore coastal wa...
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