Spatio-temporal dynamics of soil moisture driven by ‘Grain for Green’ program on the Loess Plateau, China

Abstract. To resolve a series of ecological and environmental problems over the Loess Plateau, the Grain for Green Program (GFGP) was initiated at the end of 1990s. Following the conversion of croplands and bare land on hillslopes to forests, the Loess Plateau has displayed a significant greening trend with soil erosion being reduced. However, the GFGP has also affected the hydrology of the Loess Plateau which has raised questions whether the GFGP should be continued in the future. We investigated the impact of revegetation on the hydrology of the Loess Plateau using high resolution simulations and multiple realisations with the Weather Research and Forecasting (WRF) model. Results suggests that land cover change since the launch of the GFGP has reduced runoff and soil moisture due to enhanced evapotranspiration. Further revegetation associated with the GFGP policy is likely to increase evapotranspiration further, and thereby reduce runoff and soil moisture. The increase in evapotranspiration is associated with biophysical changes, including deeper roots that deplete deep soil moisture stores. However, despite the increase in evapotranspiration our results show no impact on rainfall. Our study cautions against further revegetation over the Loess Plateau given the reduction in water available for agriculture and human settlements, without any significant compensation from rainfall.

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Satellite evidence for significant biophysical consequences of the “Grain for Green” Program on the Loess Plateau in China

Journal of Geophysical Research Biogeosciences ◽

10.1002/2014jg002820 ◽

2014 ◽

Vol 119 (12) ◽

pp. 2261-2275 ◽

Cited By ~ 73

Author(s):

Jingfeng Xiao

Keyword(s):

Loess Plateau ◽

The Loess Plateau ◽

Grain For Green ◽

Grain For Green Program

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Impact of revegetation of the Loess Plateau of China on the regional growing season water balance

Hydrology and Earth System Sciences ◽

10.5194/hess-24-515-2020 ◽

2020 ◽

Vol 24 (2) ◽

pp. 515-533 ◽

Cited By ~ 9

Author(s):

Jun Ge ◽

Andrew J. Pitman ◽

Weidong Guo ◽

Beilei Zan ◽

Congbin Fu

Keyword(s):

Soil Moisture ◽

Loess Plateau ◽

Wrf Model ◽

Weather Research And Forecasting ◽

The Loess Plateau ◽

Deep Soil ◽

Grain For Green ◽

Bare Land ◽

Biophysical Changes ◽

The Impact

Abstract. To resolve a series of ecological and environmental problems over the Loess Plateau, the “Grain for Green Program” (GFGP) was initiated at the end of 1990s. Following the conversion of croplands and bare land on hillslopes to forests, the Loess Plateau has displayed a significant greening trend, which has resulted in soil erosion being reduced. However, the GFGP has also affected the hydrology of the Loess Plateau, which has raised questions regarding whether the GFGP should be continued in the future. We investigated the impact of revegetation on the hydrology of the Loess Plateau using relatively high-resolution simulations and multiple realizations with the Weather Research and Forecasting (WRF) model. Results suggest that revegetation since the launch of the GFGP has reduced runoff and soil moisture due to enhanced evapotranspiration. Further revegetation associated with the GFGP policy is likely to further increase evapotranspiration, and thereby reduce runoff and soil moisture. The increase in evapotranspiration is associated with biophysical changes, including deeper roots that deplete deep soil moisture stores. However, despite the increase in evapotranspiration, our results show no impact on rainfall. Our study cautions against further revegetation over the Loess Plateau given the reduction in water available for agriculture and human settlements and the lack of any significant compensation from rainfall.

Download Full-text