DOI: 10.5061/dryad.0cfxpnw9t
title: Isogeochemical characterization of mountain system recharge processes in the Sierra Nevada, California

description: Mountain System Recharge processes are significant natural recharge
 pathways in many arid and semi-arid mountainous regions. However, Mountain
 System Recharge processes are often poorly understood and characterized in
 hydrologic models. Mountains are the primary water supply source to valley
 aquifers via lateral groundwater flow from the mountain block (Mountain
 Block Recharge) and focused recharge from mountain streams contributing to
 focused Mountain Front Recharge at the piedmont zone. Here, we present a
 multi-tool isogeochemical approach to characterize mountain flow paths and
 Mountain System Recharge in the northern Tulare Basin, California. We used
 groundwater chemistry data to delineate hydrochemical facies and explain
 the chemical evolution of groundwater from the Sierra Nevada to the
 Central Valley aquifer. Stable isotopes and radiogenic groundwater tracers
 validated Mountain System Recharge processes by differentiating focused
 from diffuse recharge, and estimating apparent groundwater age,
 respectively. Novel application of End-Member Mixing Analysis (EMMA) using
 conservative chemical components revealed three Mountain System Recharge
 end-members: (1) evaporated Ca-HCO3 water type associated with focused
 Mountain Front Recharge, (2) non-evaporated Ca-HCO3 and Na-HCO3 water
 types with short residence times associated with shallow Mountain Block
 Recharge, and (3) Na-HCO3 groundwater type with long residence time
 associated with deep Mountain Block Recharge. We quantified the
 contribution of each Mountain System Recharge process to the valley
 aquifer by calculating mixing ratios. Our results show that deep Mountain
 Block Recharge is a significant recharge component, representing 31 to 53
 % of the valley groundwater. Greater hydraulic connectivity between the
 Sierra Nevada and Central Valley has significant implications for
 parameterizing groundwater flow models. Our framework is useful for
 understanding Mountain System Recharge processes in other snow-dominated
 mountain watersheds.
description: We used hydrochemical and isotope data from the US Geological
 Survey Groundwater Ambient Monitoring and Assessment (GAMA) program
 (Bennett et al., 2017) and processed these data for End-Member Mixing
 Analysis (EMMA) and mixing ratio calculations using MIX program.
description: This README.txt file was generated on 2024-06-03 by Hoori Ajami GENERAL
 INFORMATION 1. **Title of Dataset:** Isogeochemical Characterization of
 Mountain System Recharge Processes in the Sierra Nevada, California 2.
 **Author Information** A. Researcher Contact Information Name: Sandra
 Armengol Vall Institution: Universidy of California at Riverside Address:
 Department of Environmental Sciences, University of California, Riverside,
 CA 92521, USA Email:
 [sandra.armengol.vall@gmail.com](mailto:sandra.armengol.vall@gmail.com) B.
 Principal Investigator Contact Information Name: Hoori Ajami Institution:
 Universidy of California at Riverside Address: Department of Environmental
 Sciences, University of California, Riverside, CA 92521, USA Email:
 [hooria@ucr.edu](mailto:hooria@ucr.edu) 3. **Date of data collection**:
 2020-05-01 - 2023-06-01 4. **Geographic location of data collection**:
 Northern Tulare Basin, California, USA 5. **Information about funding
 sources that supported the collection of the data**: National Science
 Foundation, Award: 1944161 **SHARING/ACCESS INFORMATION** 1.
 Licenses/restrictions placed on the data: CC0 1.0 Universal (CC0 1.0)
 Public Domain Dedication license. 2. Recommended citation for this
 dataset: Armengol Vall, Sandra; Ajami, Hoori; Acero Triana, Juan S.;
 O'Sickman, James; Ortega, Lucia (2024), [Model Outputs]
 Isogeochemical Characterization of Mountain System Recharge Processes in
 the Sierra Nevada, California, Dryad, Dataset,
 [https://doi.org/10.5061/dryad.0cfxpnw9t](https://doi.org/10.5061/dryad.0cfxpnw9t) **METHODOLOGICAL INFORMATION** 1. Description of methods used for collection/generation of data: Water Resources Research paper 2. Methods for processing the data: Water Resources Research paper 3. Instrument- or software-specific information needed to interpret the data: Excel, text editor, The EMMA and MIX code is open source and available on [https://idaea.csic.es/software/mix/](https://idaea.csic.es/software/mix/) **DATA-SPECIFIC INFORMATION** 1.     **Tables.zip**  A Zipped folder. Contains eight Excel files as follows: 1.1    **Table S1.xlsx** *Excel File*  Table S1. Noble gases, tritium, X2, and 3H-3He apparent ages for the Valley Aquifer wells calculated from the US Geological Survey (GAMA) Program dataset (Bennett et al., 2017). 3H-3He apparent age was computed in iNovel using a closed system equilibration model (Aeschbach-Hertig et al., 2000; Jung et al., 2013). Nobel gas concentration is in cm3STP/g, tritium is in TU, and 3H-3He apparent age is in years. 3H/4H corresponds to uncorrected value. NA = no data, LE = large error, X2&gt;1 and NT = no tritium, TU&lt;0.5. 1.2.   **Table S2.xlsx** *Excel File* Table S2. Isotope carbon ranges of C-sources used in the uncertainty analysis. 1.3    **Table S3.xlsx** *Excel File* Table S3. Well location and carbon isotope composition of groundwater samples with δ13C close to the soil (-23‰) from the 2008 GAMA database in the Mountain Aquifer Range Aquifer of the northern Tulare Basin. NA=no reported data. 1.4   **Table S4.xlsx** *Excel File* Table S4. Amount of dissolved C attributed to recharge water (Crecharge), calcite dissolution (Ccalcite), reduction of SO4 (C SO4) and methanogenesis (C CH4) and measured Ca, SO4 and Ct in groundwater. Units are mmol/L. 1.5.  **Table S5.xlsx** *Excel File* Table S5. Measured 14C values (pmC), carbon percentages for each process, determination of the initial 14C activity, and 14C apparent age (years before 1950). The 14C non-corrected age was obtained using 14Cmeasured as A0. 1.6.  **Table S6.xlsx** *Excel File* Table S6. Total CEC and composition of the exchange complex of 11 sediment samples from the Tokopah Watershed and 20 sediment samples from the Pear Watershed in Sierra Nevada (in meq/100g soil). 1.7.   **Table S7.xlsx** *Excel File* Table S7. Measured chemical composition and calculated ion imbalance and mineral saturation indices of northern Tulare Basin groundwater samples from the US Geological Survey (GAMA) Program (Bennett 287 et al., 2017). NA= no reported data, * = reported value below the analytical detection limit (4 µg L-1). 1.8.   **Table S8.xlsx** *Excel File* Table S8. Mixing ratios, along with the averages and standard deviations of 5 MIX runs with the smallest differences between the measured and estimated values using end-members from Model F. 2.      **2A.prn** *MIX Input file*  Input file for EMMA model 2a to generate Figure 10 and perform MIX analysis 3.      **B.prn** *MIX Input file*    Input file for EMMA model B to perform MIX analysis 4.      **C.prn** *MIX Input file*    Input file for EMMA model C to perform MIX analysis 5.      **D.prn** *MIX Input file*   Input file for EMMA model D to perform MIX analysis 6.      **E.prn** *MIX Input file*    Input file for EMMA model E to perform MIX analysis 7.      **F.prn** *MIX Input file*    Input file for EMMA model F to perform MIX analysis