关键词: 综合生态风险评价, 不确定性分析, 敏感性分析, 蒙特卡洛模拟

Abstract: On the basis of the integrated ecological risk assessment of China, this research chooses the risk sources data as the main source of uncertainties to analyze their impact to the risk value calculation and the sensitivities of the risk value to them. Monte Carlo smulation method is used to perform these proprieties for each pixel throughout the country with the special scale of 10 km×10 km. In the simulation progress for each pixel, the uncertainty is set firstly, and then the probability distribution of the risk source levels are computed according to their frequency statistics for at least last 50 years. At last, the simulation of risk value is carried out reference to the equitation of integrated ecological risk assessment. Meanwhile, the sensitivities of the risk value to all risk sources are got in term of Spearman rank correlation coefficients, the variance contribution of which can be used to figure out the sensitivity structure of all risk sources. The uncertainties are set as 50% and 25% to indicate high uncertainty and low uncertainty respectively, and the simulation times is set as 10000 for each pixel. The results show that 1) the simulated mean risk values are close to the calculated risk values, the ratio of them for all pixels are concentrated in 0.80?1.20 with either high or low uncertainty, and 0.95?1.05 for low uncertainty, although some differences exist between different hazard regions; 2) the simulated maximum risk values are also close to the calculated risk values, which are mostly less than one and a half of the calculated, except for the Qinghai-Tibet region; 3) for the whole country, three main risk sources that the risk value most sensitive to are droughts, floods and landslides/debris flows.

Key words: integrated ecological risk assessment, uncertainty analysis, sensitivities analysis, Monte Carlo simulation