Accounting for Climate Variability in the Design of Rain-fed Water Supply Systems in Papua New Guinea

Climate variability and El Nino Southern Oscillation (ENSO) driven weather extremes that trigger drought and flood have devastating impacts on food and water availability across Papua New Guinea. Recent El Nino driven drought has shown to be increasing in frequency and intensity. This trend will likely to continue into the future and potentially cause degradation of the natural resources that sustain the livelihood of the rural communities. Rain-water availability in PNG is strongly affected by climate drivers including ENSO and Madden Julian Oscillation, and predicting outcomes based on these drivers is essential for planning future food and water security throughout the nation. The main aim of this dissertation is to build support systems that may contribute to minimizing the impacts of climate variability in PNG. This can be possible through developing a climate-resilient sustainable design for rain-fed water systems. This dissertation addresses the research undertaken to source information on ENSO including MJO and their relationship to PNG rainfall. Research concluded that a relationship exists. Therefore, this relationship was investigated and it has confirmed that the two key climate drivers strongly impact on PNG rainfall. The impacts were found to be heterogeneous across PNG. Therefore 3 case study locations were nominated based on regional difference and climatic conditions to analyse climatic data from ENSO and MJO against rainfall data. The findings were used to enhance a typical rain-fed water supply design in each case study location. As a result, a water balance model was built that incorporated infrastructure and climate management rules designed to offset climate variability and predict upcoming dry periods. This in-turn is a climate-resilient sustainable design that can be used to counteract the impacts of climate variability on rain-fed water supply systems