Date of Graduation

Spring 2026

Degree

Master of Science in Geography and Geology

Department

School of Earth, Environment & Sustainability

Committee Chair

Mélida Gutiérrez

Abstract

Groundwater salinization poses a critical environmental concern for water resource sustainability in arid and semi-arid regions. This study evaluates spatial and temporal patterns of groundwater salinity across the state of Durango, Mexico, using total dissolved solids (TDS), sodium adsorption ratio (SAR), as salinity indicators and nitrate-nitrogen (NO₃–N) as an anthropogenic indicator. Groundwater quality data were obtained from (CONAGUA), a Mexican water agency. To assess salinity variations with respect to time, while minimizing interannual sampling bias, two multi-year sampling periods were selected: 2012-2013, and 2020-2021. Final datasets consisted of 122 wells for 2012–2013 and 131 wells for 2020–2021. The wells were spatially classified into exorheic (open-basin) and endorheic (closed-basin) hydrologic regions using watershed boundaries in ArcGIS Pro. Spatial distribution maps were generated using Empirical Bayesian Kriging interpolation. Descriptive statistics and Spearman’s rho correlation coefficient analyses were applied separately to each basin system. Statistical results indicated consistently higher salinity within the endorheic system across both periods. Mean TDS concentrations in the endorheic system increased from approximately 583 mg/L (2012–2013) to 628 mg/L (2020–2021), with maximum values exceeding 2,000 mg/L, whereas the exorheic system maintained lower mean TDS values (≈282–320 mg/L) and maximum concentrations below 750 mg/L. The endorheic system also exhibited stronger positive correlations between TDS and NO₃–N (ρ = 0.535 in 2012–2013; ρ = 0.498 in 2020–2021), reflecting solute accumulation processes under restricted drainage conditions. In contrast, exorheic systems displayed weak correlations between NO₃–N and TDS (|ρ| < 0.25) and persistent negative correlations between NO₃–N and SAR (ρ ≈ −0.46 to −0.56) indicative of minimal agriculture activity and climatic differences, resulting in reduced solute accumulation.

Keywords

salinity, cluster analysis, GIS, water quality, endorheic, exorheic, groundwater, Durango, Mexico, EBK

Subject Categories

Applied Statistics | Climate | Environmental Chemistry | Environmental Indicators and Impact Assessment | Environmental Monitoring | Geology | Hydrology | Multivariate Analysis | Other Earth Sciences | Statistical Methodology | Water Resource Management

Copyright

© Juan Lopez-Sierra

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Open Access

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