Processes Governing Alkaline Groundwater Chemistry within a Fractured Rock (Ophiolitic Mélange) Aquifer Underlying a Seasonally Inhabited Headwater Area in the Aladağlar Range (Adana, Turkey)

Abstract

The aim of this study was to investigate natural and anthropogenic processes governing the chemical composition of alkaline groundwater within a fractured rock (ophiolitic mélange) aquifer underlying a seasonally inhabited headwater area in the Aladaglar Range (Adana, Turkey). In this aquifer, spatiotemporal patterns of groundwater flow and chemistry were investigated during dry (October 2011) and wet (May 2012) seasons utilizing 25 shallow hand-dug wells. In addition, representative samples of snow, rock, and soil were collected and analyzed to constrain the PHREEQC inverse geochemical models used for simulating waterrock interaction (WRI) processes. Hydrochemistry of the aquifer shows a strong interseasonal variability where Mg-HCO 3 and Mg-Ca-HCO 3 water types are prevalent, reflecting the influence of ophiolitic and carbonate rocks on local groundwater chemistry. R-mode factor analysis of hydrochemical data hints at geochemical processes taking place in the groundwater system, that is, WRI involving Ca-and Si-bearing phases; WRI involving amorphous oxyhydroxides and clay minerals; WRI involving Mg-bearing phases; and atmospheric/anthropogenic inputs. Results from the PHREEQC modeling suggested that hydrogeochemical evolution is governed by weathering of primary minerals (calcite, chrysotile, forsterite, and chromite), precipitation of secondary minerals (dolomite, quartz, clinochlore, and Fe/Cr oxides), atmospheric/anthropogenic inputs (halite), and seasonal dilution from recharge.

Estimation of recharge in mountain hard-rock aquifers based on discrete spring discharge monitoring during base-flow recession

“…Such values are in the low range of EC previously observed in literature for groundwater in ophiolitic aquifers (typically up to 2,000 μS/cm; e.g. Abdalla et al 2016;Dewandel et al 2005;Güler et al 2017), suggesting a short groundwater-rock interaction time. In particular, EC values <850 μS/cm are representative of quick shallow groundwater circulation following Dewandel et al (2005).…”

Estimation of Physical and Chemical Properties of Groundwater of Selected Area From Al-Dhalia Directorate, Al-Dhalia Gov., Yemen

“…In Yemen, groundwater is considered as the main water source for drinking, domestic uses and irrigation purposes [6]. The mountainous headwater systems and the impacts of anthropogenic activities on headwater-scale has been largely impeded by their small size, large numbers, remote locations, rugged terrain, harsh climate conditions, and lack of road access, logistics, and available data [7]. In the study area of the Al-Dhalia District, Al-Dhalia governorate, surface and groundwater suffer from accelerated chemical contamination from domestic wastewater, nitrogenous fertilizers and pesticides.…”

Relationship Between Aquifer Processes and Groundwater Quality: A Case of Olbanita Aquifer System, Lower Baringo Basin, Kenya Rift

“…Large field experimental and geochemical laboratory data sets require proper management, elaboration, and interpretation tools and techniques. 6 Güler et al 10 noted that the interpretation of associations exclusively based on graphical techniques is fraught with difficulties owing to the simultaneous nature of aquifer processes and their effects. Recent studies by Nwankwoala, 11 Pazand, 9 Moghimi, 12 and Rotiroti et al 6 established the value of multivariate techniques such as principal component analysis (PCA) and hierarchical clustering analysis (HCA) in the provision of quantitative measures of correlation between water quality parameters and fundamental aquifer processes.…”