Regional development boundary of China's Loess Plateau: Water limit and land shortage

The planetary boundary concept aims to define the environmental limits within which humanity can safely operate in the global scale. Identification of the regional development boundary and solutions for problems therein is the basis of the local and global earth system sustainable operation. The Loess Plateau in China is an ideal area for studying the regional development boundary concept. After reviewing the main natural and anthropogenic changes on the Loess Plateau and their hydrological and social-economic effects during recent decades, we identified the water limit for large scale revegetation and the land shortage caused by the Grain for Green project as the most important determinants of the regional development boundary. Therefore, it is necessary to readjust the existing revegetation strategy according to the water capacity, including identifying the suitable priority zones and the corresponding species, density and management for keeping the planted ecosystem healthy. In addition, as an integrative mode of land management, gully reclamation can not only create cropland and conserve soil and water, but also strengthen the construction of agricultural infrastructure, foster large-scale agricultural operations and promote the development of rural economy.