The Impact of Climate Change on the Upper Navet Reservoir, Trinidad

Abstract

A hydrologic study of the Upper Navet Reservoir and its catchment was conducted to investigate and evaluate the potential impacts of climate change on it, using the soil moisture accounting algorithm in HEC-HMS to perform continuous simulations. The catchment is partially gauged, with a single rainfall gauge located within it. With the absence of a stream gauge, recorded stage data from the reservoir was used to evaluate catchment response. The selection of model parameters was based on previous work on the nearby Nariva catchment that was improved by a manual optimisation technique. The model was subject to a split-sample test with a calibration period of 24 months (2003-2004) on a daily time-step followed by validation over a period of 60 months (2005-2009). The validated model was used to evaluate the system’s response to climate change. The meteorological data for this was generated by the PRECIS software for this region. The model was subject to three data sets based on the SRES A1B scenario. The results of simulations conducted for the period 2030-2096 showed that for continuous operation, production rates at the Navet reservoir require a 40% reduction of present values for two of these scenarios and 30% for the most optimistic scenario.