Quantitative Analysis of Safety Risks and Relationship with Delayed Project Completion Times.

Dynamic work environments in construction and civil infrastructure sectors remain susceptible to safety risks. Although previous research has resulted in improvements, there is currently a gap in measuring temporal impacts of safety risks quantitatively. Precise modeling of potential delays caused by safety incidents is vital for efficient management of risks and making informed decisions on project contingency. Toward this aim, the current research adopts a nondeterministic modeling method to simulate and quantify safety incidents and find correlations with project delays. Using a deductive approach, three research questions were formulated, and investigations conducted on Australian data collected from 2016 onwards. Quantitative impacts of safety risks on project completion times were numerically measured. Furthermore, safety risks were ranked based on their significance of temporal impacts on project performance. This paper contributes to the theory of safety management by developing a nondeterministic method to model impacts of safety risks at both industry and project levels. Practical contributions and outcomes can facilitate using machine learning methods to plan proportionate time buffers to address safety risks.

Modeling hydrological impacts of afforestation on intermittent streams.

Although the majority of river networks across the world are intermittent or ephemeral, afforestation management of these catchments is mostly founded on studies in perennial catchments. The hydrological model CATHY (CATchment HYdrology) was used here to simulate the effects that different degrees of progressive conversion from pasture to plantation have on the streamflow generation in intermittent streams. The model was applied to two rural catchments with different size and topographic features in southwest Victoria, Australia. Simulated scenarios included different levels of plantation establishment in pasture areas planting gradually from downslope to upslope and vice versa. Different models for root water uptake were compared to account for water stress, oxygen stress, and root water compensation. A function of root growth over time was also explored to see how it affected model results. The model results show that complex interactions between topographic features and afforestation patterns are crucial in controlling catchments hydrological behavior. In particular, results show that planting in the prone-saturation areas has the largest effects on streamflow. Oxygen stress has a more significant impact than root water compensation on streamflow changes. A time dependent root growth results in smaller streamflow reduction on average, although with different impacts on the two catchments, also due to the interplay between topography and plantation patterns. Overall, our results show that there are multiple factors affecting the water balance when a catchment is partially or completely afforested and those must be taken into account when implementing forestry management strategies.