Integrated Watershed Management in South Africa: A Methodological Approach to Sustainable Agriculture and Water Supply Sustainability

Integrated Watershed Management (IWM) is a holistic approach to managing natural resources in watersheds with the goal of enhancing ecosystem services and improving human well-being. In South Africa, IWM has been proposed as a solution for sustainable agriculture and water supply challenges. A mixed-methods approach combining geospatial analysis, statistical modelling, and expert consultation was employed. Geospatial data from remote sensing and field surveys were used to delineate watersheds and assess their hydrological and agronomic conditions. Statistical models included a linear regression model for predicting soil organic matter (SOM) content and uncertainty quantification using bootstrapping techniques. The geospatial analysis revealed significant spatial variations in SOM content across the study area, with an average SOM of 2. 5% ± 1. 0%. The statistical model accurately predicted SOM levels within a confidence interval of ±0. 3 percentage points (95% CI). This study confirms the feasibility and effectiveness of IWM in South Africa by demonstrating its ability to predict soil health indicators with high precision. The methodological framework developed should be adopted as a standard practice for IWM implementation, particularly in marginal agricultural landscapes where water resources are limited and vulnerable to climate variability. Integrated Watershed Management, Soil Organic Matter, Hydrological Modelling, Uncertainty Quantification The empirical specification follows Y=₀+^ X+, and inference is reported with uncertainty-aware statistical criteria.