Land degradation dynamic in the first decade of twenty-first century in the Beijing–Tianjin dust and sandstorm source region

Land degradation dynamic assessment is very important to understand the effectiveness of ecological engineering and provide decision support for future restorations. Taking the Beijing–Tianjin dust and sandstorm source region (BTSSR) as the study area, the land degradation dynamic in the first decade of twenty-first century is assessed by utilizing the time series trends of net primary production (NPP) and modified rain use efficiency (RUE), respectively, and their sensitivities and performances are evaluated through the validation. The results shows that (1) a widespread degradation in the BTSSR is identified from 2000 to 2010, with a proportion of 52.7 % by using NPP, and 65.2 % when using RUE; (2) the proposed RUE is effective in eliminating high correlations between NPP and precipitation, and overcame the problem that the RUE assumption often breaks down at the pixel scale, through incorporating the land degradation assessment division; and (3) the RUE is preferred for land degradation assessment with a higher accuracy (93.5 %), compared with NPP (81 %), which can provide valuable insights into the land degradation assessment in the arid and semi-arid regions.