Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Hydrol. Earth Syst. Sci., 21, 2233-2248, 2017
http://www.hydrol-earth-syst-sci.net/21/2233/2017/
doi:10.5194/hess-21-2233-2017
© Author(s) 2017. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
26 Apr 2017
Historical and future trends in wetting and drying in 291 catchments across China
Zhongwang Chen1,2, Huimin Lei1,2, Hanbo Yang1,2, Dawen Yang1,2, and Yongqiang Cao3 1Department of Hydraulic Engineering, Tsinghua University, Beijing, 100084, China
2State Key Laboratory of Hydro-Science and Engineering, Tsinghua University, Beijing, 100084, China
3School of Urban Planning and Environmental Science, Liaoning Normal University, Dalian, 116029, China
Abstract. An increasingly uneven distribution of hydrometeorological factors related to climate change has been detected by global climate models (GCMs) in which the pattern of changes in water availability is commonly described by the phrase dry gets drier, wet gets wetter (DDWW). However, the DDWW pattern is dominated by oceanic areas; recent studies based on both observed and modelled data have failed to verify the DDWW pattern on land. This study confirms the existence of a new DDWW pattern in China after analysing the observed streamflow data from 291 Chinese catchments from 1956 to 2000, which reveal that the distribution of water resources has become increasingly uneven since the 1950s. This pattern can be more accurately described as drier regions are more likely to become drier, whereas wetter regions are more likely to become wetter. Based on a framework derived from the Budyko hypothesis, this study estimates runoff trends via observations of precipitation (P) and potential evapotranspiration (Ep) and predicts the future trends from 2001 to 2050 according to the projections of five GCMs from the Coupled Model Intercomparison Project Phase 5 (CMIP5) under three scenarios: RCP2.6, RCP4.5, and RCP8.5. The results show that this framework has a good performance for estimating runoff trends; such changes in P play the most significant role. Most areas of China, including more than 60 % of catchments, will experience water resource shortages under the projected climate changes. Despite the differences among the predicted results of the different models, the DDWW pattern does not hold in the projections regardless of the model used. Nevertheless, this conclusion remains tentative owing to the large uncertainties in the GCM outputs.

Citation: Chen, Z., Lei, H., Yang, H., Yang, D., and Cao, Y.: Historical and future trends in wetting and drying in 291 catchments across China, Hydrol. Earth Syst. Sci., 21, 2233-2248, doi:10.5194/hess-21-2233-2017, 2017.
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Short summary
The significant climate changes remind us to characterize the hydrological response to it. Based on the long-term observed hydrological and meteorological data in 291 catchments across China, we find a pattern of the response stating that drier regions are more likely to become drier, whereas wetter regions are more likely to become wetter. We also reveal that the precipitation changes play the most significant role in this process.
The significant climate changes remind us to characterize the hydrological response to it. Based...
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