水保所知识产出(1956---)知识库

Since the implementation of the Grain for Green Project (GFGP) in the 1990s, the warming
and wetting trend in the Loess Plateau is becoming statistically significant in the context of climate
change. However, the correlation between precipitation increase and the regional vegetation restora-
tion is still controversial. To explore the main factors influencing the regional precipitation change,
this study selected five potential influencing factors including potential evapotranspiration (PET),
normalized difference vegetation index (NDVI), precipitable water (PW), surface temperature (ST),
and water vapor transport (WVT). We used the statistical methods to analyze the spatial-temporal
distribution of precipitation before and after the GFGP and to quantify the relative influence degree
of different factors to precipitation change. The results show that: (1) The precipitation increased
significantly (95% confidence level) after the GFGP, with an increase rate of 4.96 mm a − 1 ; (2) from
the perspective of spatial-temporal distribution, the precipitation in the southern part of the Loess
plateau was significantly increasing with an increase rate of 20–50 mm in the period of 2000–2014;
(3) the relative influence degree of NDVI to precipitation increased after the GFGP, and the annual
precipitation (PRE A ) and summer precipitation (PRE S ) was more influenced by NDVI (relative influ-
ence degree of 30.18% and 31.37%, respectively) compared with winter precipitation. In winter, the
PW and the PET are the main influencing factors for the precipitation change with relative influence
degrees of 30.13% and 27.64%, respectively. Based on this study, we speculate that the warming and
wetting trend of the 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.