LAUSR

Based on the primary data such as temperature, precipitation, MODIS⁃GPP and MODIS⁃ET datasets at monthly scale from 2000 to 2014, using pixel⁃based time⁃lay patial correlation analysis, the climate time⁃lag effect of water use efficiency (WUE) and its effective factors on the Loess Plateau of northern Shaanxi were analyzed. The results showed that under the influence of the ecological project of converting farmland to forestry or grassland and the climate change, the interannual WUE in the Loess Plateau of northern Shaanxi showed a fluctuating trend, among which, 2001—2003 decreased significantly, 2003—2005 and 2010—2013 increased significantly, and the change ranged from 1.06 to 1.67 gCmmm from 2000 to 2014. Influenced by different vegetation types, the intraannual WUE showed three kinds of changes: rapid double peak, slow double peak and single peak. WUE in the Loess Plateau of northern Shaanxi had obvious time⁃lag effect on precipitation, and the lag time was mostly 3 months. But the response degree and time⁃lag of WUE to