Exploring the role of land restoration in the spatial patterns of deep soil water at watershed scales

• Published in: Catena (Giessen) 2019-01, Vol.172, p.387-396
• Main Authors: Zhao, Yali, Wang, Yunqiang, Wang, Li, Zhang, Xiaoyan, Yu, Yunlong, Jin, Zhao, Lin, Henry, Chen, Yiping, Zhou, Weijian, An, Zhisheng
• Format: Article
• Language: English
• Subjects: Deep soil; Grain for Green project; Gully Land Consolidation project; Land use; Soil water management; The Loess Plateau
• ISSN: 0341-8162; 1872-6887
• DOI: 10.1016/j.catena.2018.09.004

Soil water is a key variable for re-vegetation and environmental restoration in water-limited terrestrial ecosystems such as the Chinese Loess Plateau. Large land restoration projects (e.g., the “Grain for Green” launched in 1999 and the “Gully Land Consolidation” launched in 2011) had substantial impacts on the storage, distribution, and spatial patterns of soil water, and these factors remain poorly understood across watershed scales. We measured the amount of water stored in soil layers from the surface down to 5 m depth and characterized the vertical distribution of gravimetric soil water content (SWC) among four land uses (cropland, shrubland, forestland, and orchard), two slope aspects (shady vs. sunny), and two landforms (slope vs. gully) in three watersheds on the Chinese Loess Plateau. All three of the watersheds were affected by Grain for Green project, two were affected by the Gully Land Consolidation project (named NG and GT-T watersheds) and one was unaffected by restoration efforts (named GT-U watershed). In the three watersheds, the slope and gully SWCs varied from 2.4 to 24.2% and from 4.8 to 46.6%, respectively, during the sampling period in October 2015 (end of the rainy season). The amount and vertical distribution of slope SWC differed significantly among the land uses and between shady and sunny slopes in the three watersheds (p