Defining climate zone of Borneo based on cluster analysis

Although Borneo Island is one of the most vulnerable tropical regions to climate change, maps depicting the local climate conditions employing climate classification are still not well defined. The present study attempted regional climate classification to divide the Borneo region into several homogenous groups based on long-term average climate behavior. Daily gridded rainfall and temperature (Tavg, Tmax, and Tmin) data at 0.25° resolution spanning 56 years (1960–2016) was used. The classification was done using non-hierarchical k-mean and several hierarchical methods, namely, Single , Complete , McQuitty , Average , Centroid , Median , and two algorithms of Ward’s method, wardD , and wardD2 . The results showed that k-mean , wardD , and wardD2 were able to classify the climate of Borneo into four zones, namely ‘dry and hot’ (DH), ‘wet and hot’ (WH), ‘wet’ (W), and ‘wet and cold’ (WC) with a considerable difference at the boundaries. Spatial relevancy, stability, and variability of the clusters based on correlation and compromise programming showed that the wardD method was the most likely to yield acceptable results with optimum 4-cluster to partition the area into four principal climate zones. The constructed cluster plot, centroid plot, and probability distribution function (PDF) showed a distinct climatic characteristic between the climate zones in terms of rainfall, temperature, and seasonality. The proposed climate zonation for Borneo can help in better understanding climate regionality and climate-related development planning.