When and where did the Loess Plateau turn “green”? Analysis of the tendency and breakpoints of the normalized difference vegetation index

Cao, Z., et al., 2018. Land Degradation and Development

Original research (primary data)
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The Loess Plateau experiences the most serious soil erosion problems in China and possibly even globally. Many measures have been taken to increase the vegetation cover and to control soil erosion. Of these measures, the Grain for Green Project, launched in 1999, has been the most effective, changing the ecological and socio-economic situation of the Plateau significantly. Using time series normalized difference vegetation index (NDVI) data from 1981 to 2013, this study analysed spatial patterns of changes in vegetation cover, detected spatial patterns of the abrupt-change time of NDVI trends, and investigated factors that may contribute to these changes. The results showed that (a) vegetation restoration was obvious over the last decades, especially in the 2000s, and the increase in NDVI during 2000-2013 was more than 3-times that during 1990-2000. Approximately 54.99% of the Plateau during 2000-2013 had a statistically significant increase, mainly distributing in loess hilly and gully region and loess gully region. (b) Vegetation restoration was comprehensively affected by climate change and human activities (e.g., the Grain for Green Project, urbanization and policies), and the effects of each factor varied for different regions. (c) Vegetation in most of the Plateau began to increase around 2007-2010, and 4 discrete areas with different timings of such break points were detected. The difference in the timing of break points in NDVI may be related with precipitation, reproducing tree species, management measures, and survival rate. These results imply that integrating natural and human factors is important when making effective and suitable measures and policies.

Case studies

Basic information

  • Case ID: INT-196-1
  • Intervention type: Created habitats
  • Intervention description:

    Afforestation from the Grain for green; “the GGP was the largest and most effective ecological construction project in China (Y. P. Chen et al., 2015; Lü et al., 2012; S. Wang, Fu, et al., 2015). A pilot project was initiated in Shaanxi, Sichuan, and Gansu in 1999. The nationwide implementation occurred in two phases after 2002.”

  • Landscape/sea scape ecosystem management: Yes
  • Climate change impacts Effect of Nbs on CCI Effect measures
    Biomass cover loss  Positive NDVI
  • Approach implemented in the field: Yes
  • Specific location:

    The Loess Plateau region; This region covers an area of some 650,000 km2 in the upper and middle reaches of China's Yellow River, accounting for 6.76% of China's land area, and includes 341 counties in seven provinces (all of Shanxi and Ningxia; almost all of Shaanxi; and parts of Henan, Inner Mongolia, Gansu, and Qinghai)

  • Country: China
  • Habitat/Biome type: Created forest |
  • Issue specific term: Not applicable


  • Notes on intervention effectivness: To test for intervention effectiveness, measure correlation between NDVI and the cumulative afforestation area ratio (i.e., the ratio of the afforestation area to the administrative area) "the correlation between NDVI trends and the afforestation area at county scale in different regions (i.e., the entire Loess Plateau and the SIA and IA areas) during 2001–2013 was significant (p < .05). Meanwhile, the relation- ship between NDVI and the afforestation area in the key areas (e.g., the SIA area, the BP2007 area, and the BP2008 area) was more significant than that in other areas (e.g., the IA area and the BP2010; Table 1). These all indicated that the GGP is beneficial for vegetation restoration in the Plateau, especially in the key areas of the project."
  • Is the assessment original?: Yes
  • Broadtype of intervention considered: Not applicable
  • Compare effectivness?: No
  • Compared to the non-NBS approach: Not applicable
  • Report greenhouse gas mitigation?: No
  • Impacts on GHG: Not applicable
  • Assess outcomes of the intervention on natural ecosystems: No
  • Impacts for the ecosystem: Not reported
  • Ecosystem measures:
  • Assess outcomes of the intervention on people: No
  • Impacts for people: Not reported
  • People measures:
  • Considers economic costs: No
  • Economic appraisal conducted: No
  • Economic appraisal described:
  • Economic costs of alternative considered: No
  • Compared to an alternative: Not reported

Evaluation methodology

  • Type of data: Quantitative
  • Is it experimental: No
  • Experimental evalution done: Not applicable
  • Non-experimental evalution done: Empirical case study
  • Study is systematic: