Impact of Agriculture on the Quality of Groundwater Resources in Peri-Urban Zone of Songon (Cote D'ivoire)

Abstract

The expansion of agro-industrial exploitations and the increased use of pesticides is a major concern for the quality of groundwater resources in the Abidjan area. The objective of this study is to assess the global vulnerability to pollution of these resources. Therefore, two methods based on the DRASTIC model were used. These methods are DRASTICLU and DRASTICLU-P in which land use is considered as a parameter, extending to 8 the number of analyze parameters in order to make the results more robust. To assess the significance of different parameters, a sensitivity test has been calculated. Validation of the results was made from the calculation of map error (Er) on the resulting maps, to see which is best suited for this study. The results show that the global vulnerability to pollution remains generally high in the area. These areas of high and very high vulnerability are found on almost all of the study areas, but with a strong presence in center and north. Together, high and very high vulnerability cover almost 84% of the study area. These areas are highly dependent on the recharge, aquifer media, soil media and the vadose zone. The calculation of uncertainties gave relatively high values due to high overall standard deviations. Calculated map errors are 22% and 21.5% respectively for DRASTICLU-P and DRASTICLU. Although these values are substantially equal, show that the DRASTICLU-P method remains the most suitable.

GIS-based DRASTIC and composite DRASTIC indices for assessing groundwater vulnerability in the Baghin aquifer, Kerman, Iran

“…This could be due to the high theoretical weight assigned to this factor (weight = 5). These findings are similar to those obtained by Dibi et al (2012), who have shown that, in addition to this parameter, topography, net recharge, and water table depth have a high impact on the vulnerability index. In addition, according to Samake et al (2011), the vadose zone and hydraulic conductivity had a significant impact on the vulnerability index that appears to have a moderate sensitivity to the deletion of water table depth (1.48 %), net recharge (1.36 %), and hydraulic conductivity (1.25 %).…”

“…Most of these techniques are based on analytic tools to associate groundwater contamination with land operations. There are three types of evaluation methods: process-based simulations, statistic procedures, and overlay and index approaches (Neshat et al, 2014;Dixon, 2004).…”

Contribution of the Sensitivity Analysis in Groundwater Vulnerability Assessing Using the DRASTIC and Composite DRASTIC Indexes

“…This could be due to the high theoretical weight allocated to this factor (weight = 5). These findings are similar to those obtained by Dibi et al (2012) who have shown that in addition to this parameter, topography, net recharge, and water table depth have a high impact on the vulnerability index. Also, in Samake et al (2011) study, the impact of the vadose zone and the hydraulic conductivity parameters had a considerable impact on the vulnerability index.…”

Development of a Model for Assessing Vulnerability to Pollution of Groundwater in Fissured Aquifers: The Case of the Ehania Watershed (South-Eastern Côte d’Ivoire)

“…Several methods have been adopted to assess the vulnerability. There are DRASTIC [5], GOD [6], AVI [7], SINTACS [8] and many other small methods including the properties of the environment (DISCO, DRASTIC-fm, DRATIC-P, DRASTICLU) have been studied [9]. However, all these methods, although effective, only allow the evaluation of vulnerability to pollution in a punctual way, i.e.…”