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Numerical wind mapping is currently the wind power industry's standard for preliminary assessments for sites of good wind resources. Of the various available numerical models, numerical weather prediction (NWP) models are best suited for modeling mesoscale wind flows across small islands. In this study, the Weather Research and Forecast (WRF) NWP model was optimized for simulating the wind resources of the Caribbean islands of Trinidad and Tobago in terms of spin-up period for developing mesoscale features, the input initial and boundary conditions, and the planetary boundary layer (PBL) parameterizations. Hourly model simulations of wind speed and wind direction for a one-month period were compared with corresponding 10 m level wind observations. The National Center for Environmental Prediction (NCEP)-Department of Energy (DOE) reanalysis of 1.875° horizontal resolution was found to be better suited to provide initial and boundary conditions (ICBCs) over the 1° resolution NCEP final analysis (FNL); 86% of modeled wind speeds were within ±2 m/s of measured values at two locations when the coarse resolution NCEP reanalysis was used as compared with 55--64% of modeled wind speeds derived from FNL. Among seven PBL schemes tested, the Yonsei University PBL scheme with topographic drag enabled minimizes the spatial error in wind speed (mean bias error +0.16 m/s, root-mean-square error 1.53 m/s and mean absolute error 1.21 m/s) and is capable of modeling the bimodal wind speed histogram. These sensitivity tests provide a suitable configuration for the WRF model for mapping the wind resources over Trinidad and Tobago, which is a factor in developing a wind energy sector in these islands. [ABSTRACT FROM AUTHOR]

Underestimating costs in major public sector social infrastructure development projects is a highly contested and problematic issue. Several gaps exist in the identification of root causes of cost overruns. Behavioural science academics advocate political and psychological explanations as root causes for cost overruns against technical factors, such as errors and omissions by engineers, practitioners and scientists. Most studies in this field primarily concentrate on developed countries. Although some studies have been undertaken in developing countries, very little attention is given to the Small Island Developing States (SIDS). This paper presents a case study of public sector social housing construction programmes in a Caribbean SIDS to further understand the root causes of cost overruns. Primary and secondary data spanning across two different political cycles were collected to test the concepts of whether political influences or technical influences are the true root causes of cost overruns. It was found that political explanations based on the psycho-strategic concept are the leading sources of cost risks on the final estimated contract price. This study strengthens the argument and discusses how strategic decisions emanating from the political directorate outweigh and influence informed technical decisions formulated during the planning stages. [ABSTRACT FROM AUTHOR]