[A-HW19] Hydrology & Water Environment

[AHW19-13] Dry gets drier and wet gets wetter (DDWW) paradigm is subject to the choice of datasets

*Abhishek Abhishek^1,2, Jinghua Xiong³, Shenglian Guo³, Jie Chen³, Jiabo Yin³ (1.Indian Institute of Science, India, 2.Tokyo Institute of Technology, Japan, 3.Wuhan University, China)

Keywords:Climate change, DDWW paradigm, Multimodal assessments

In the premise of intensifying hydrological cycle, the DDWW (Dry gets drier, and wet gets wetter) paradigm has been used to quantify the impact of climate change on various hydrometeorological variables (e.g., precipitation, evaporation) or a combination thereof. However, no one has attempted to examine the validity of this much-debated paradigm from the terrestrial water storage (TWS) change perspective. Considering the essential role of TWS in the wetting and drying of the land system, here (Hydrol. Earth Syst. Sci., 26, 6457–6476, https://doi.org/10.5194/hess-26-6457-2022), we built upon a large ensemble of TWS datasets, including different satellite-based products, global hydrological models, and land surface models to evaluate the DDWW hypothesis during the historical period (1985–2014) with a 0.05 significance level. We find that 11.01%–40.84% (range by various datasets) of global land confirms the DDWW paradigm, while 10.21% –35.43% of the area shows the opposite pattern. We demonstrate that different choices of data sources can reasonably influence the test results up to a four-fold difference. Our findings will provide insights and implications for global wetting and drying trends from the perspective of TWS change under climate change and highlight the need for careful inferences from the DDWW paradigm.