A multi-approach assessment of land use effects on groundwater quality in a karstic aquifer

Abstract

Groundwater represents almost half of the drinking water worldwide and more than one third of water used for irrigation. Agro-industrial activities affect water resources in several manners; one of the most important is leaching of agrochemical residues. This research identifies the major contributors of changes in groundwater quality comparing two contrasting land uses in a karstic area of the Yucatan peninsula as case study. Using a multiple approach, we assess the impact of land use with physicochemical data, multivariate analyses, hydrogeochemistry and nitrate isotopic composition. We confirmed that agricultural land use has a greater impact on groundwater quality, observed in higher concentration of nitrates, ammonium, potassium and electrical conductivity. Seasonality has an influence on phosphates and the chemical composition of the groundwater, increasing the concentration of dissolved substances in the rainy season. There was a clear effect of manure application in the agricultural zone and the nitrate isotopic composition of groundwater points toward recharge in certain areas. We consider that seasonality and land use effects are intertwined and sometimes difficult to separate, likely because of land use intensity and hydrogeochemical process at a local scale. Finally, we observed poor groundwater quality in the agricultural area during the wet season; thus, it is desirable to maintain nonagricultural areas that provide groundwater of appropriate quality.

Water Quality and Hydrogeochemical Characteristics of Some Karst Water Sources in Apuseni Mountains, Romania

“…In Dobrogea, another important karst area in Romania, Moldovan et al reported excellent to good water quality and, for a couple of sources, the presence of possible health risk due to the high content of NO 3 − , Cd and Cr [47]. Nitrate pollution is one of the most important causes of groundwater pollution, being the main reason for poor groundwater quality in a karst region in Central America [54], while TDS is reported to be the reason for the poor quality of a groundwater in Tefenni, Turkey [55]. Water with low quality is mainly characterized by high values of NO 3 − , Cl − , SO 4 2− , Ca, Mg and Na, due to natural interactions such as weathering of rocks and evaporation processes, or to anthropogenic influences, especially pollution with organic materials subject to underground nitrification processes.…”

Physical and Biogeochemical Characterization of a Tropical Karstic Marsh in the Yucatan Peninsula, Mexico.

“…IW has a more de ned chemical composition, the carbonate minerals are around equilibrium, but it also acquired characteristics of in ltrating water that has passed through the soil, such as acidic pH, reductive conditions and organic matter decomposition (Craft et al 1991). Similar electrical conductivity in GW and IW is assumed as comparable amount of dissolved solids was found in those compartments; the former due to the water-rock interaction (Smith et al 2020), the latter due to the solubilisation of several substances around the rhizosphere (Raghavendra et al 2016). In summary, this marsh is a good site to evaluate in detail the water in ltration process and the chemical changes that occur in the water during this process.…”

Contaminated Groundwater by Nitrate in Sidoarum Village, Godean District, Sleman Regency, Special Region of Yogyakarta

“…32 ISSN 2549-7197 (cetak), ISSN 2549-564X (online) JMEL, Volume 5 Nomor 1, 2021 Smith et al (2020) stated that residential areas could be a nitrate contributor to the environment associated with septic tank leakage with higher concentrations. So it is necessary to control and monitor good sanitation channels in waste disposal so that it does not become a source of pollution.…”