Abstract:
study examines the impact of sediment transport indices (STI) on nitrate concentration in downstream water
bodies. The research highlights rainfall’s significant role in predicting seasonal nitrate levels. Employing GISSWPT
tools and hydro-geomorphologic analysis, cropland sub-watersheds, particularly sub-watersheds one
and three, are prioritized for their high contribution to downstream surface and groundwater nitrate contamination,
with prioritization values of 105.58 and 180.63, respectively. Statistical analysis, conducted using Python’s
scikit-learn library, validated the findings of the study, with the model’s F-statistic of 79.63 and a
corresponding p-value of 0.0147 underscoring its overall significance. However, while STI alone showed a prioritization
parametric correlation coefficient of 0.5077, suggesting other external factors also contribute to nitrate
loading, a strong relationship between STI and nitrate concentration was revealed (R2 of 0.993). This
integrated approach enhances understanding of how geomorphologic parameters of cropland sub-watersheds
influence water quality downstream. By clarifying the complex interactions between sediment transport and
nitrate concentration, evidence-based strategies can be developed to mitigate surface and groundwater nitrate
pollution. This research provides valuable insights into cropland sub-watershed pollution dynamics and informs
targeted management interventions
