摘要
Aquifer vulnerability is a critical issue across the entire globe due to the depletion of groundwater and escalation of pollution levels, which poses a detrimental effect on the natural environment. To ascertain this contamination risk, an extensive study has been conducted to assess the aquifer vulnerability by using the F-hydra model. This paper presents the vulnerability technique for the theory and application of flow accumulation, land-use and hydraulic conductivity. The model was applied to a shallow aquifer in eastern Ghana’s Volta River Basin, with the results being compared to the standardised DRASTIC model. The model follows the aquifer vulnerability assessment concept of the source pathway receptor where flow accumulation represents the ponding areas with downward percolation of contaminant to the water table, land-use represents the human activities at the land surface, and hydraulic conductivity represents the driving force leading to the movement of contaminant. The results reveal that the moderate vulnerability region covers 51.55% (2598.12 km<sup>2</sup>) of the entire area. The high and low vulnerability regions cover a significant percentage of the area 1.13% (56.52 km<sup>2</sup>) and 47.32% (2384.93 km<sup>2</sup>), respectively. The final vulnerability index was largely influenced by the removal of the hydraulic conductivity and land-use parameters. The model was validated with nitrate concentration in drilled wells in the study area. The maps produced in this study could be utilised as a guide to vulnerability by policymakers, groundwater manager and planners aimed at preserving the integrity of this vulnerable resource.
Aquifer vulnerability is a critical issue across the entire globe due to the depletion of groundwater and escalation of pollution levels, which poses a detrimental effect on the natural environment. To ascertain this contamination risk, an extensive study has been conducted to assess the aquifer vulnerability by using the F-hydra model. This paper presents the vulnerability technique for the theory and application of flow accumulation, land-use and hydraulic conductivity. The model was applied to a shallow aquifer in eastern Ghana’s Volta River Basin, with the results being compared to the standardised DRASTIC model. The model follows the aquifer vulnerability assessment concept of the source pathway receptor where flow accumulation represents the ponding areas with downward percolation of contaminant to the water table, land-use represents the human activities at the land surface, and hydraulic conductivity represents the driving force leading to the movement of contaminant. The results reveal that the moderate vulnerability region covers 51.55% (2598.12 km<sup>2</sup>) of the entire area. The high and low vulnerability regions cover a significant percentage of the area 1.13% (56.52 km<sup>2</sup>) and 47.32% (2384.93 km<sup>2</sup>), respectively. The final vulnerability index was largely influenced by the removal of the hydraulic conductivity and land-use parameters. The model was validated with nitrate concentration in drilled wells in the study area. The maps produced in this study could be utilised as a guide to vulnerability by policymakers, groundwater manager and planners aimed at preserving the integrity of this vulnerable resource.
