Due to the inherent hazardous characteristics associated with dolomite and development on dolomite, quantification of the stability attributes related to dolomite is essential. In large parts of South Africa, development on dolomite is inevitable due to the location thereof. The purpose of this study is to define an implementation framework for decision-making with regards to development on dolomite. The decision-making process is based on a dolomite stability investigation conducted by AGES North West (AGES, 2012) within Sarafina, Ikageng. The results from this study are interpreted by means of a decision support system that is based on the geo-environmental setting of the study area and the geotechnical properties related to the subsurface profile. This includes but is not limited to: Geo-environmental site conditions: • Drainage • Topography • Geophysical conditions • Regional geological conditions • Local geological conditions • Regional groundwater conditions • Local groundwater conditions Geotechnical stability of the dolomite based on the hazard characterisation and evaluation procedures: • Percussion drilling data • Receptacle development • Mobilisation agencies • Potential surface manifestation development space • Nature and mobilisation potential of the blanketing layer • The bedrock morphology These parameters are all inter-related and affect each other in various ways. During the study the importance of site specific observations and interpretations are emphasized. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013

Due to the inherent hazardous characteristics associated with dolomite and development on dolomite, quantification of the stability attributes related to dolomite is essential. In large parts of South Africa, development on dolomite is inevitable due to the location thereof. The purpose of this study is to define an implementation framework for decision-making with regards to development on dolomite. The decision-making process is based on a dolomite stability investigation conducted by AGES North West (AGES, 2012) within Sarafina, Ikageng. The results from this study are interpreted by means of a decision support system that is based on the geo-environmental setting of the study area and the geotechnical properties related to the subsurface profile. This includes but is not limited to: Geo-environmental site conditions: • Drainage • Topography • Geophysical conditions • Regional geological conditions • Local geological conditions • Regional groundwater conditions • Local groundwater conditions Geotechnical stability of the dolomite based on the hazard characterisation and evaluation procedures: • Percussion drilling data • Receptacle development • Mobilisation agencies • Potential surface manifestation development space • Nature and mobilisation potential of the blanketing layer • The bedrock morphology These parameters are all inter-related and affect each other in various ways. During the study the importance of site specific observations and interpretations are emphasized. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013

Joint probability methods for assessing storm surge flood risk involve the use of a collection of hydrodynamic storm simulations to fit a response surface model describing the functional relationship between storm surge and storm parameters like central pressure deficit and the radius of maximum wind speed. However, in areas with a sufficiently low probability of flooding, few storms in the simulated storm suite may produce surge, with most storms leaving the location dry with zero flooding. Analysts could treat these zero-depth, “non-wetting” storms as either truncated or censored data. If non-wetting storms are excluded from the training set used to fit the storm surge response surface, the resulting suite of wetting storms may have too few observations to produce a good fit; in the worst case, the model may no longer be identifiable. If non-wetting storms are censored using a constant value, this could skew the response surface fit. The problem is that non-wetting storms are indistinguishable, but some storms may have been closer to wetting than others for a given location. To address these issues, this thesis proposes the concept of a negative surge, or “pseudo-surge”, value with the intent to describe how close a storm came to causing surge at a location. Optimal pseudo-surge values are determined by their ability to improve the predictive performance of the response surface via minimization of a modified least squares error function. We compare flood depth exceedance estimates generated with and without pseudo-surge to determine the value of perfect information. Though not uniformly reducing flood depth exceedance estimate bias, pseudo-surge values do make improvements for some regions where <40% of simulated storms produced wetting. Furthermore, pseudo-surge values show potential to replace a post-processing heuristic implemented in the state-of-the-art response surface methodology that corrects flood depth exceedance estimates for locations where very few storms cause wetting.