A new climate scenario for assessing the climate change impacts on soil moisture over the Huang–Huai–Hai Plain region of China

Abstract

To assess the impacts of temperature and precipitation changes on surface soil moisture (SSM) in the Huang–Huai–Hai Plain (3H) region of China, the approach of conditional nonlinear optimal perturbation related to parameters (CNOP-P) and the Common Land Model are employed. Based on the CNOP-P method and climate change projections derived from 22 global climate models from CMIP5 under a moderate emissions scenario (RCP4.5), a new climate change scenario that leads to the maximal change magnitudes of SSM is acquired, referred to as the CNOP-P type temperature or precipitation change scenario. Different from the hypothesized climate change scenario, the CNOP-P-type scenario considers the variation of the temperature or precipitation variability. Under the CNOP-P-type temperature change, the SSM changes in the last year of the study period mainly fluctuate in the range from −0.014 to +0.012 m3 m−3 (−5.0% to +10.0%), and from +0.005 to +0.018 m3 m−3 (+1.5% to +9.6%) under the CNOP-P-type precipitation change scenario. By analyzing the difference of the SSM changes between different types of climate change scenarios, it is found that this difference associated with SSM is obvious only when precipitation changes are considered. Besides, the greater difference mainly occurs in north of 35°N, where the semi-arid zone is mainly situated. It demonstrates that, in the semi-arid region, SSM is more sensitive to the precipitation variability. Compared with precipitation variability, temperature variability seems to play little role in the variations of SSM.