47 cut across the mining areas and are inferred to be in hydraulic connection with the aquifer system. Two previous numerical groundwater flow models have been developed for the area: an initial Lubambe model in MINEDW (2017, updated 2018) and a subsequent FEFLOW model (2018). Both models share important limitations: each was originally focused on a single mine site with limited representation of others, both relied on the 2018 Leapfrog geologic model, and both reported limited model calibration data. Predictive simulations from these models indicate that pumping (or absence of pumping) at Konkola alone may change Mingomba dewatering requirements by 30 to 40 percent, illustrating both the importance of regional connectivity and the substantial uncertainty in any single deterministic forecast. Effective dewatering planning at Mingomba therefore requires a methodology that explicitly quantifies pre-operational uncertainty rather than relying on a single calibrated base case, and that can be applied at a stage when site-specific dewatering data does not yet exist. 2. OBJECTIVES This study has three linked objectives: 1. To quantify pre-operational uncertainty in pore pressure evolution at Mingomba under a defined five-year dewatering scenario, by sampling probabilistic prior distributions over different stratigraphic units, vertical permeability anisotropy in confining layers, a bulk fracture permeability multiplier, and regional aquifer recharge boundaries. 2. To identify, through global sensitivity analysis, which uncertain hydrogeological parameters most strongly control predicted pressure evolution and therefore which parameters represent the highest-priority targets for further data acquisition. 3. To structure the modelling work as a sequential test of two competing hydrogeological hypotheses of increasing complexity, identifying the minimum model complexity that observed pressure data at the site can support, and that decisions about dewatering design require. The two competing hypotheses are formulated as follows: H1: Hydraulic anisotropy at Mingomba, represented as a directionally variable permeability tensor in a single-porosity continuum model, is sufficient to reproduce observed pressure data and predict pore pressure evolution under dewatering. Fracture effects are captured implicitly through bulk directional permeability without explicit fracture geometry. H2: Where H1 is insufficient, pressure evolution is governed by dual porosity behaviour, in which the rock matrix and fracture system constitute two interacting domains that exchange fluid through a transfer coefficient, producing delayed drainage responses that a single-porosity model cannot reproduce. Explicit representation of discrete fracture networks and individual faults is excluded from the present scope due to limited structural data at the site; their effects are represented
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