Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Hydrol. Earth Syst. Sci., 21, 183-196, 2017
http://www.hydrol-earth-syst-sci.net/21/183/2017/
doi:10.5194/hess-21-183-2017
© Author(s) 2017. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
10 Jan 2017
Effects of land use/land cover and climate changes on surface runoff in a semi-humid and semi-arid transition zone in northwest China
Jing Yin1, Fan He1, Yu Jiu Xiong2,3, and Guo Yu Qiu4 1State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
2Department of Water Resource and Environments, School of Geography and Planning, Sun Yat-Sen University, Guangzhou 510275, China
3Department of Land, Air and Water Resources, University of California at Davis, Davis, CA 95618, USA
4Shenzhen Engineering Laboratory for Water Desalinization with Renewable Energy, School of Environment and Energy, Peking University, Shenzhen 518055, China
Abstract. Water resources, which are considerably affected by land use/land cover (LULC) and climate changes, are a key limiting factor in highly vulnerable ecosystems in arid and semi-arid regions. The impacts of LULC and climate changes on water resources must be assessed in these areas. However, conflicting results regarding the effects of LULC and climate changes on runoff have been reported in relatively large basins, such as the Jinghe River basin (JRB), which is a typical catchment (> 45 000 km2) located in a semi-humid and arid transition zone on the central Loess Plateau, northwest China. In this study, we focused on quantifying both the combined and isolated impacts of LULC and climate changes on surface runoff. We hypothesized that under climatic warming and drying conditions, LULC changes, which are primarily caused by intensive human activities such as the Grain for Green Program, will considerably alter runoff in the JRB. The Soil and Water Assessment Tool (SWAT) was adopted to perform simulations. The simulated results indicated that although runoff increased very little between the 1970s and the 2000s due to the combined effects of LULC and climate changes, LULC and climate changes affected surface runoff differently in each decade, e.g., runoff increased with increased precipitation between the 1970s and the 1980s (precipitation contributed to 88 % of the runoff increase). Thereafter, runoff decreased and was increasingly influenced by LULC changes, which contributed to 44 % of the runoff changes between the 1980s and 1990s and 71 % of the runoff changes between the 1990s and 2000s. Our findings revealed that large-scale LULC under the Grain for Green Program has had an important effect on the hydrological cycle since the late 1990s. Additionally, the conflicting findings regarding the effects of LULC and climate changes on runoff in relatively large basins are likely caused by uncertainties in hydrological simulations.

Citation: Yin, J., He, F., Xiong, Y. J., and Qiu, G. Y.: Effects of land use/land cover and climate changes on surface runoff in a semi-humid and semi-arid transition zone in northwest China, Hydrol. Earth Syst. Sci., 21, 183-196, doi:10.5194/hess-21-183-2017, 2017.
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Short summary
Conflicting results on the effect of the land use/land cover (LULC) and climate changes on runoff have been reported for relatively large basins. After quantifying the impacts of LULC and climate changes on surface runoff using the Soil and Water Assessment Tool, we concluded that large-scale LULC has had an important effect on the water cycle and that the conflicting findings on the effect of the LULC and climate changes on runoff are likely caused by uncertainty in hydrological simulations.
Conflicting results on the effect of the land use/land cover (LULC) and climate changes on...
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