Current rainfall Intensity-Duration-Frequency (IDFs) curves generally were developed based on stationary extreme value assumption. However, climate change is expected to alter extreme rainfalls and invalidate the stationary assumption. So, it is crucial to develop future rainfall IDFs taking into account the impacts of climate change. Difficulty in preparing reliable rainfall time series with fine time step and capturing extremes for future climate scenarios has led to limited studies aimed at investigating the change of IDF curves due to climate change. In this paper, a robust stochastic rainfall model (NSRP) is employed to produce future rainfall IDFs for five stations across Karkheh and Karun basins in Iran. NSRP can generate long-term realistic rainfall series containing extremes. Moreover, it applies changes in different rainfall statistical characteristics, projected by GCMs, in the downscaling procedure. For each station, the model was calibrated using observed rainfalls series. Then, 3000-year daily rainfall series were generated, and historical IDFs were developed. Consequently, NSRP parameters were perturbed based on GCM projections. Then, 3000-year future rainfall series were generated, and future IDFs were developed. The climate change uncertainties were represented by employing two GCM (CanESM2 and HadGem2) and three emission scenarios (RCP2.6, RCP4.5, and RCP8.5). The results showed NSRP is able to reproduce observed extreme rainfalls in a wide range of time scales. Also, climate change will lead to a considerable increase in future extreme rainfall intensity in the study basins. As averages of all considered scenarios, rainfall intensities will increase between 22 and 206% in the future.

当前的降雨强度-持续时间-频率（IDF）曲线通常是基于平稳极值假设得出的。但是，预计气候变化会改变极端降雨，并使固定假设无效。因此，考虑到气候变化的影响，发展未来的降雨IDF至关重要。难以准备具有精细时间步长的可靠降雨时间序列并难以捕捉未来气候情景的极端情况，导致旨在调查IDF曲线因气候变化而变化的研究有限。在本文中，采用了鲁棒的随机降雨模型（NSRP）来为伊朗Karkheh和Karun盆地的五个站点生成未来的降雨IDF。NSRP可以生成包含极端值的长期实际降雨序列。此外，它在缩小程序中应用了GCM预测的不同降雨统计特征的变化。对于每个站点，使用观测到的降雨序列对模型进行校准。然后，产生了3000年的日降雨序列，并建立了历史IDF。因此，基于GCM预测扰动了NSRP参数。然后，产生了3000年的未来降雨序列，并开发了未来的IDF。通过使用两个GCM（CanESM2和HadGem2）和三个排放情景（RCP2.6，RCP4.5和RCP8.5）来表示气候变化的不确定性。结果表明，NSRP能够在很宽的时间范围内再现观测到的极端降雨。另外，气候变化将导致研究盆地未来极端降雨强度的显着增加。作为所有已考虑方案的平均值，