Hydrogeological connectivity and microbiological contamination by Escherichia coli: A GIS application in the Santa Marta Micro-Watershed, Tarrazú, Costa Rica
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| Auteurs: | , |
|---|---|
| Formaat: | artículo original |
| Status: | Versión publicada |
| Publicatiedatum: | 2026 |
| Omschrijving: | Introduction: In the Santa Marta micro-watershed, Tarrazú, Costa Rica, high concentrations of Escherichia coli (E. coli) have been reported, although the specific sources and mechanisms for this contamination were unclear. Objective: To analyze the influence of land use and hydrogeological conditions on E. coli. microbiological contamination in a tropical micro-watershed. Methods: We produced a relative concentration GIS (Geographic Information System) map of E. coli based on 64 water analyses conducted between July 2022 and October 2023. This was compared with potential concentration models integrating three main factors: land use, hydrogeological vulnerability, and basic soil infiltration capacity. Results: Sixty percent of the river network was classified within the High fecal contamination range, with average concentrations exceeding 1,600 MPN. Land use was dominated by agricultural crops (55% of the area), followed by urban areas (15%) and forest cover (25%). The first model (soil use + hydrogeologic vulnerability) achieved better adjustment in agricultural and forested areas, while the second (soil use + hydrogeologic vulnerability + soil infiltration) performed better in urban sectors. Conclusion: E. coli contamination in the Santa Marta micro-watershed is primarily associated with residential occupation of sites with hydrogeological vulnerability and flood-prone areas. Septic tanks were a key source of coliforms, which infiltrate groundwater and are later discharged into rivers. This process may also include contributions from sources located outside the topographic watershed, underscoring the importance of considering the hydrological basin as the functional unit of analysis. |
| Land: | Portal de Revistas UNED |
| Instelling: | Universidad Estatal a Distancia |
| Repositorio: | Portal de Revistas UNED |
| OAI Identifier: | oai:revistas.uned.ac.cr:article/6179 |
| Online toegang: | https://revistas.uned.ac.cr/index.php/index/article/view/6179 |
| Keyword: | Escherichia coli soil infiltration test hydrogeological vulnerability urban encroachment multi-criteria evaluation GIS micro-watershed management pruebas de infiltración vulnerabilidad hidrogeológica invasión urbana evaluación multicriterio SIG manejo de microcuencas |