EGU2020-12005
https://doi.org/10.5194/egusphere-egu2020-12005
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

The spatial and temporal characteristics of precipitation and the key contributing factors in the Loess Plateau since the implementation of Green for Grain Project

Xuerui Gao1, Jichao Wang2, Yubao Wang3, Xining Zhao4, Yong Zhao5, and Miao Sun6
Xuerui Gao et al.
  • 1Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100,China (gaoxuerui666@163.com)
  • 2College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China(wangjichao0208@163.com)
  • 3College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China(wyb0406@sina.com)
  • 4Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100,China (xiningz@aliyun.com)
  • 5State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China(zhaoyong@iwhr.com)
  • 6College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China(sunmiao19930526@163.com)

      Since the implementation of Green for Grain Project (GFGP) in the 1990s, the precipitation in the Loess Plateau has increased significantly. The warming and wetting trend in this area is becoming statistically significant. However, the correlation between precipitation increase and regional vegetation restoration is still controversial. To explore the main factors influencing the regional precipitation change, this study selected 6 main contributing factors of the precipitation in the Loess Plateau based on the cloud-precipitation physics and used the statistical methods to analyze the long-term change trend and the spatial and temporal distribution of precipitation in the Loess plateau before and after GFGP and to quantify the contribution rate of different factors to precipitation change in this area. The results show that: 1) the precipitation increased significantly (95% confidence level) after Green for Grain Project since 1999, with an increase rate of 4.96 mm/a; 2) From the perspective of spatial and temporal distribution, the precipitation in the southern part of the Loess plateau was significantly increasing with an increase rate of 20-50mm in the period of 2000-2015 compared with the average annual value in the base period (1985-1999). Among them, the summer precipitation increased significantly, while the winter precipitation changed non-significantly; 3) The contribution analysis shows that the summer precipitation in the Loess Plateau is mainly affected by regional actual evapotranspiration (AET) and vegetation coverage (NDVI) after GFGP, with the contribution rates of 27.1% and 40.0%, which respectively indicates that the summer precipitation in the Loess Plateau increased mainly due to the regional vegetation restoration and the associated ET increase. The winter precipitation in the Loess Plateau is mainly affected by the precipitable water (PW) in the air and water vapor flux (VF), with the contribution rates of 33.5% and 31.7%, which indicates that the winter precipitation is mainly affected by atmospheric circulation and transport of external water vapor. Based on this study, we speculate that the warming and wetting trend of Loess Plateau in recent years is not only closely related to global climate change, but also significantly affected by local climate change brought by vegetation restoration. The above conclusions are important for future ecological restoration and water resources management in the water-scarce Loess Plateau.

How to cite: Gao, X., Wang, J., Wang, Y., Zhao, X., Zhao, Y., and Sun, M.: The spatial and temporal characteristics of precipitation and the key contributing factors in the Loess Plateau since the implementation of Green for Grain Project, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12005, https://doi.org/10.5194/egusphere-egu2020-12005, 2020