Simulating hourly rainfall occurrence within an equatorial rainforest, Borneo Island / Simulation de l'occurrence de pluie horaire au sein de la forêt équatoriale, Ile de Bornéo

• Published in: Hydrological sciences journal 2009-06, Vol.54 (3), p.571-581
• Main Authors: CHAPPELL, NICK A., DISCENZA, ANTONIO R., TYCH, WLODEK, WHITTAKER, JOE, BIDIN, KAWI
• Format: Article
• Language: English
• Subjects: chaîne de Markov; climat tropical; generalized linear model (GLM); générateur météorologique; hourly rainfall; Markov chain; modèle linéaire généralisé (GLM); Monte Carlo simulation; pluie horaire; probabilités de transition évolutives; simulation de Monte-Carlo; time-varying transition probabilities; tropical climate; weather generator
• ISSN: 0262-6667; 2150-3435
• DOI: 10.1623/hysj.54.3.571

The ability to simulate characteristics of the diurnal cycle of rainfall occurrence, and its evolution over the seasons is important to the forecasting of hydrological impacts resulting from land-use and climate changes within the humid tropics. This stochastic modelling study uses a generalized linear model (GLM) solution to second-order Markov chain models, as these discrete models are better at describing binary occurrence processes on an hourly time-scale than continuous-time approaches such as stochastic state-space models. We show that transition probabilities derived by the Markov chain method need to be time-varying rather than stationary to simulate the evolution of the diurnal cycle of rainfall occurrence over a Southeast Asian monsoon sequence. The conceptual and pragmatic links between discrete diurnal processes and continuous processes occurring over seasonal periods are thereby simulated within the same model.