Time-lapse Agricultural Pollution Study at a Tranche of 4 km2 Survey at the Gidan Kwano Campus Development Phase II, Minna, Nigeria

Abstract

The result of interpretation of the data-field of a 4 km2 dual vertical electrical sounding (VES)induced polarisation (IP) survey at the planned Gidan Kwano Campus Development Phase II, Federal University of Technology (FUT), Minna, northcentral Nigeria, indicated groundwater prospect locations predominantly along the southernmost cross-profiles. It is instructive to investigate whether the applications of pesticides and inorganic fertilisers have had any deleterious effects on the properties of the near-surface soil of the region of a groundwater location or locations along particular cross-profiles. Three passes of VES in-line and cross-line survey [traditional three dimensional (3-D) layout] over two-weekly interval were conducted in the local farming season for both the in-line and cross-line grids. For the agricultural pollutants leaching regime aspect of this study, the “correlation threshold” parameter was set at 70%. For P4-1: the suite of correlations is 70%:51%:72% for the three time sequences (thus, the groundwater prospect location is not at risk from agrochemical pollution). For P6-2: the suite of correlations is 60%:-55%:41% (thus, the groundwater prospect location is at risk from agrochemical pollution). For P15-3: the suite of correlations is -103%:-107%:-109% (thus, the groundwater prospect location is at risk from agrochemical pollution). For P20-4: the suite of correlations is 96%:80%:89% (thus, the groundwater prospect location is not at risk from agrochemical pollution). For P1-5: the suite of correlations is 76%:82%:84% (thus, the groundwater prospect location is not at risk from agrochemical pollution). Ultimately, a novel “Agricultural Pollutants Leaching Regime” was created from the tandem surveys conducted at the five southernmost cross-profiles of the area of study, and it is recommended that a broader “Threat Indicator” for the larger 4km2 tranche of the Gidan Kwano Campus Development Phase II be produced in subsequent studies; this “Threat Indicator” document should be produced yearly, especially to keep tab on the prospect locations that have not yet been drilled for boreholes. The result of such an audit mechanism process would then be a public enlightenment advocacy geared towards the reduction of indiscriminate use of agrochemicals.