Key hydrological processes in the Del Azul Creek basin, sub-humid Pampean Plain.

Groundwater plays an important role in the economic development of the Chaco-Pampean Plain (Argentina), where industry, agriculture and cattle farming are the main economic activities. The 66% of the country's popu-lation lives in this area. The low slopes of this region condition the water mov...

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Detalles Bibliográficos
Autores: Zabala, M. Emilia, Gorocito, Martín, Dietrich, Sebastián, Varni, Marcelo, Sánchez Murillo, Ricardo, Manzano Arellano, María del Sol, Ceballos, Elina
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2021
País:España
Institución:Universidad Politécnica de Cartagena(UPCT)
Repositorio:Repositorio Digital UPCT
OAI Identifier:oai:repositorio.upct.es:10317/13357
Acceso en línea:http://hdl.handle.net/10317/13357
https://www.sciencedirect.com/science/article/pii/S0048969720357879?via%3Dihub
Access Level:acceso abierto
Palabra clave:Hydrological-physical processes
Stable isotopes
Rainwater
Surface water
Groundwater
Pampeano aquifer
Explotación de Minas
2506.05 Hidrogeología
2503 Geoquímica
2508.10 Precipitación
Descripción
Sumario:Groundwater plays an important role in the economic development of the Chaco-Pampean Plain (Argentina), where industry, agriculture and cattle farming are the main economic activities. The 66% of the country's popu-lation lives in this area. The low slopes of this region condition the water movement and the occurrence of phys-ical and chemical processes. The aim of this work is to update the hydrological conceptual model of the Del Azul Creek basin (Buenos Aires Province), a sub-humid and continental plain, using environmental tracers. In total, the study was based on the analysis of 201 samples (stable isotopes) and 184 samples (chemical data) including rain-water, surface water and groundwater. The temporal and spatial variation in the isotopic composition of rainfall and the hydrological physical-processes, evaporation, surface water-groundwater interaction and recharge were studied. Isotopic compositions of rainfall revealed a seasonal variation across the basin. Low δ18O rainfalls occur during the coldest seasons, while high δ18O rainfalls occur during the warmest seasons. The isotopic composi-tions of rainfall varied only during the cold period in the upper basin. At this time, the lowest δ18O rainfall fell in the upper basin, while in the other areas and during the warmer seasons, no differences were observed. Evap-oration was a relevant process in the flatter area of the basin, mainly during the warmest seasons. Samples taken from the wetlands and from the lower section of the Del Azul Creek were strongly evaporated. In the first 30 m depth of the aquifer, groundwater reflected the isotopic composition of rainfall from the warmest seasons, thus revealing seasonal preferential recharge and a good hydraulic connection. This study provides direct evidence showing that both evaporation and the surface water-groundwater interaction are processes that play a key role in the control of the isotopic and chemical composition of water.