Erosion in the Loess Plateau : scales and silos of the grain to green project, 1999-2003

Abstract

This thesis explores the relationship between environmental restoration and social-economic factors. It focuses on the erosion treatment on the Loess Plateau, especially the Grain to Green Project (GGP), the biggest national-range environmental treatment program in China in recent years. GGP produced significant impact on local landform, landuse and livelihood. On one hand, the program effectively controlled torrent by increasing soil aggregation; on the other hand, it lacked long-term perspectives and had underestimated the complexity of the environment and of local residents. The thesis seeks to bridge the gaps between soil treatment policy and the actual effect. Research was conducted on soil erosion across multiple scales and key issues are generated based on typical cases. Findings from the research serve as guidelines for the following design proposition. The design applies hierarchical method, including both top-down and bottom-up interventions. First, a division method for erosion states was developed which can divide the erosion problem within the range of the yellow river into small catchment basins. Second, a typical catchment basin was selected as an example to show proposed strategy in three scales: catchment, slope and patches. The core design idea is to conserve resources and maximize output in sustainable ways. The fragmented land patches are integrated to complete the production model. The study site is planned according to field condition, such as erosion process, slope ratio, lighting, water resource and distance to settlements. Patches were identified using vegetation coverage and appropriate planting strategies were proposed accordingly. In sum, the thesis is a critique of existing GGP. A new solution is proposed that can mitigate the conflict of soil erosion treatment and socio-economic development of local communities.