Origen, potential and water quality of a perennial spring in Juárez city mountains, Chihuahua, México

Abstract

A Small Perched Perennial Spring has been used for Irrigation for 25 years. With an area of 23.3 ha its water potential basin varies from 90.7 to 979 m3/day so water conductivity of (k=62 cm/day producing between 0.30 to 3.17 lt/sec for lowest to highest rain return period (PR1 to PR100). Water Quantity and Hydraulic conductivity already mentioned were evaluated: Firstly, RPS structure were formed for 100 m of thick impervious lowermost member Lagrima Formation (Kli) overloading for a medium porosity (Klm, Klu) as well as high porosity of Finlay and del Norte Formations (Kf, Kdn). Secondly, Rainfall-Runoff-Recession hydrology model with Recession constant of 0.6 and ratio to pick of 0.2 in the threshold were used trough the simulation. Thus, Base (underground) and Direct (surface) runoff were separated. Finally, water quality and its interaction with host rocks were performed so; two water samples were collected and studied. Both samples were qualified as: Calcic-Bicarbonated (6f-C2) with low salinization risk (C3-S2). Therefore, water could be used for irrigation. In addition, water interaction among Cretaceous rocks of Sierra de Juárez as Lagrima (Kl), Finlay (Kf) and del Norte (Kdn) formations suggests three cases; One; If Calcium reduces Sodium increases given a sodic shale-slate system as: Ca2+HCO3+shales+Na+→Na++HCO3+shales+Ca2, this suggests that water have been confined by rock sourced Cretaceous Lagrima formation (Kli). Two, RPS overloaded recharge layers; Finlay (Kf) and (Kdn) with high karstification potential as high porosity is evident so: Three. If Na+ differ from Cl- thus, the cationic exchange has more Na+ than Cl- so more risk to karstification arises as mentioned before.