Investigating regional groundwater flow systems in baja california central desert region

Abstract

In Northern Baja California, environmental conservation may not be fully accomplished in the absence of a clear understanding of key factors controlling and protecting biodiversity. Groundwater is an environmental agent triggering the presence of a wide range of arid ecosystems; therefore, any sustainable development in the region has to maintain a balance between environmental, social and economical benefits. The present study has placed a great emphasis on the understanding and distribution of groundwater flow systems, and their environmental interactions in the protected area of the Valle de Los Círios, using physical-chemical and isotope methods. Results show the presence of three groundwater groups portraying contrasting flow systems conditions. Analyzed samples have been classified as fresh-brackish, and thermal alkaline groundwater as suggested by pH, temperature and TDS. The Br/Cl ratio in most samples was close to the ocean molar value (1.5x10 -3 ) indicating the importance of marine aerosol fraction in the recharged waters; however, Mg/Cl,Na/Cl,Ca/Cl,SO 4 / Cl and Cl/HCO 3 +Cl ratios were significantly different to those of seawater mixing conditions. Dominant ions (Na,Ca and Cl), chemical age proxies (Li), and δ 18 O suggest waters with long residence time, with the possibility of been recharge during the late glacial period. Thermal ground water shows low minor and trace element content and exhibits the dominance of Na-plagioclase hydrolysis; their low levels of Sr and Ba suggest negligible contact with calcareous rocks and their estimated temperature at depth (80to100°C) and TDS suggest groundwater has travelled through fractured media. This introduction study suggests that desertic species in Valle de Los Cirios are highly sustained by groundwater of local and intermediate flows.

Volcanic and Saline Lithium Inputs to the Salar de Atacama

“…The high pH, Na concentration and alkalinity of WC1 indicate high CO 2 inputs and hydrolysis of Na-rich silicates. Similar compositions were reported for groundwater in Baja California, which had undergone deep but rapid flow through fractured igneous and metamorphic rocks [50]. However, the high TDS of WC1 suggests a long residence time or higher weathering rates, possibly influenced by elevated temperatures.…”

Geochemistry and Provenance of Springs in a Baja California Sur Mountain Catchment

“…Down‐canyon, the spring waters were associated slightly more with Na–K–Cl type waters, suggesting moderate dissolution of the rhyolitic aquifer material (Figure 3B). Major ion compositions of samples in this study showed less fluid‐rock interaction than regional groundwaters published by Ouysse et al (2018). The ranges found for Ca/Na (0.8 to 2.4) and Alkalinity/Na (1.5 to 4.2) correspond to silicate weathering with Ca/Na relatively larger values compared with the one found in large rivers (0.3 to 1) but well below the typical range for carbonate weathering (20 to 80) (Gaillardet et al 1999).…”

“…These values are consistent with the conclusion of Eastoe et al (2015) that recharge to groundwater systems is primarily from tropical storms. δ 18 O and δ 2 H isotopes of spring water collected in this study were representative of the range of the regional shallow groundwaters (Wassenar et al 2009;Kretzschmar and Frommen 2013;Birkle et al 2016;Tamez-Meléndez et al 2016;Ouysse et al 2018).…”

Enfoque regional de manejo integrado del agua en la microcuenca El Pantano, Morelos, México

“…Los complejos procesos que actúan sobre múltiples escalas espaciales y temporales complican el nivel de acción; la cuenca hidrológica debe ser la base para entender la función adecuada de los sistemas de flujo y los procesos, así como para la correcta planificación y gestión del agua y el territorio (Carrillo-Rivera y Cardona, 2008;Ouysse et al, 2018;Yu y Duffy, 2018).…”