ABSTRACT

Climate change impact analysis in urban hydrology involves downscaling of coarse climate model outputs. This study evaluates the downscaling skill of four change factor methods for impact analysis on urban hydrology in Belgium. The downscaling methods are applied to precipitation observations. For this, the 100-year Uccle time series is split in observations, in pseudo-climate model runs and in an evaluation period. Conceptual models for a retention basin and sewer system are thereafter forced with the downscaled time series and the time series for the evaluation period. The downscaling skill is determined based on the reproduction of precipitation and impact statistics. Results show that the skill depends on the stormwater system and the impact variable. Due to climate variability, none of the methods is found outperforming. It is therefore recommended to apply a more thorough analysis, which also employs the long-term projections.

摘要

城市水文学中的气候变化影响分析涉及粗略气候模型输出的缩减。本研究评估了四种改变因子方法在比利时城市水文学影响分析中的降尺度技巧。降尺度方法适用于降水观测。为此，将100年的Uccle时间序列分为观测值，伪气候模型运行和评估期。此后，使用缩减的时间序列和评估期的时间序列来强制执行保留池和下水道系统的概念模型。降级技巧是根据降水和影响统计数据的再现来确定的。结果表明，该技能取决于雨水系统和影响变量。由于气候多变性，没有发现任何一种方法的效果好。