Spatiotemporal dynamics of rainfall interception and effective precipitation in the Loess Plateau after large‐scale afforestation

Abstract

AbstractThe Grain for Green Program (GFGP) has promoted vegetation restoration and environmental improvement in the Loess Plateau (LP) and has sparked considerable interest in its effects on local hydrological cycle processes. However, few studies have examined the spatiotemporal evolution characteristics of rainfall interception (RI) and its influencing factors in the LP after GFGP implementation, even though RI directly controls the potential available water resources entering the ecosystem (Peffective) and largely influences the changes in hydrological fluxes in water‐limited regions. This study employed the remote sensing (RS)‐Gash model to investigate RI and Peffective in the LP. Results showed that RI and Peffective increased at a rate of 0.7 (p < 0.01) and 2.5 mm/year (p = 0.12), respectively, during the complete implementation of the GFGP (2001–2018). Spatially, the two were dominated by significantly increasing (area share, 50.3%) and nonsignificantly increasing (74.2%) trends, respectively. The dominant drivers of the changes in RI and Peffective are vegetation factors and precipitation, respectively. The results imply that after the implementation of the GFGP, water scarcity in most areas of the LP seems to show signs of improvement, rather than worsening at source. However, people should remain alert about issues that can occur in semihumid areas, including vegetation's degradation due to excessive afforestation or single‐species plantations, particularly at the Ziwuling Mountains. The successful greening experience of the GFGP in the LP is worth promoting, but lessons should also be learned regarding its unsustainability in areas with relatively abundant water.