Sensitivity analysis of the rice model WARM in Europe: exploring the effects of different locations, climates and methods of analysis on model sensitivity to crop parameters

摘要

An application of Morris and Sobol' sensitivity analysis methods to the rice model WARM is presented to assess model sensitivity to its parameters. The output considered is aboveground biomass at maturity, simulated at five European rice districts (France, Greece, Italy, Portugal, Spain) for years characterized by low, intermediate, and high continentality. The total-effect index of Sobol' and Morrisindices (mean µ and standard deviation of the ratios output changes/parameter variations) were used as sensitivity measures. Radiation use efficiency (RUE), optimum temperature (Topt), and leaf area index at emergence (LAIini) were generally ranked as first, second and third most relevant parameters. Exceptions were observed, depending on the sensitivity method (e.g. LAIini resulted not relevant by the Morris method), or site-continentality pattern (e.g. with intermediate continentality in Spain, LAIini and Topt were second andthird ranked; with low continentality in Portugal, RUE was outranked by Topt). Low s values associated with the most relevant parameters indicated limited parameter interactions. The importance of sensitivity analyses by exploring location × climate combinations is discussed as pre-requisite to evaluate either novel crop modelling approaches or the application of known modelling solutions to conditions not exploredpreviously. The need of developing tools for sensitivity analysis within the modelling environment is also emphasized.