Acta Geographica Sinica ›› 2020, Vol. 75 ›› Issue (11): 2307-2318.doi: 10.11821/dlxb202011003

• Climate and Environment Change • Previous Articles     Next Articles

Impacts of climate and land use/cover changes on runoff in the Hanjiang River basin

TIAN Jing(), GUO Shenglian(), LIU Dedi, CHEN Qihui, WANG Qiang, YIN Jiabo, WU Xushu, HE Shaokun   

  1. State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
  • Received:2019-05-09 Revised:2020-08-25 Online:2020-11-25 Published:2021-01-25
  • Contact: GUO Shenglian E-mail:jingtian@whu.edu.cn;slguo@whu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(51539009)

Abstract:

As a link between the atmosphere and the geosphere, the hydrological cycle is affected by both climate change and Land Use/Cover Change (LUCC). However, most existing research on runoff response focused mainly on the impact of the projected climate variation, neglecting the influence of future LUCC variability. Therefore, the objective of this study is to examine the co-impacts of both projected climate change and LUCC on runoff generation. Firstly, the future climate scenarios under BCC-CSM1.1 and BNU-ESM are both downscaled and corrected by the Daily Bias Correction (DBC) model. Secondly, the LUCC scenarios are predicted based on the Cellular Automaton-Markov (CA-Markov) model. Finally, the Soil and Water Assessment Tool (SWAT) model is used to simulate the hydrological process under different combinations of climate and LUCC scenarios, with the attempt to quantitatively evaluate the impacts of climate change and LUCC on runoff generation. In this study, the Hanjiang River basin is used as the case study area. The results show that: (1) compared with the base period (1966-2005), the annual rainfall, daily maximum and minimum air temperatures during 2021-2060 will have an increase of 4.0%, 1.8 ℃, 1.6 ℃ in RCP4.5 scenario, respectively, while 3.7%, 2.5 ℃, 2.3 ℃ in RCP8.5 scenario, respectively. (2) During 2010-2050, the area proportions of forest land and construction land in the study area will increase by 2.8% and 1.2%, respectively, while those of farmland and grassland will decrease by 1.5% and 2.5%, respectively. (3) Compared with the single climate change or LUCC scenario, the variation range of future runoff under both climate and LUCC is the largest, and the influence of climate change on future runoff is significantly greater than that of LUCC. This study is helpful to maintain the future water resources planning and management of the Hanjiang River basin under future climate and LUCC scenarios.

Key words: climate change, LUCC, CA-Markov model, runoff responses, Hanjiang River basin