Articles | Volume 20, issue 12
Research article
01 Dec 2016
Research article |  | 01 Dec 2016

Hydrological recovery in two large forested watersheds of southeastern China: the importance of watershed properties in determining hydrological responses to reforestation

Wenfei Liu, Xiaohua Wei, Qiang Li, Houbao Fan, Honglang Duan, Jianping Wu, Krysta Giles-Hansen, and Hao Zhang

Abstract. Understanding hydrological responses to reforestation is an important subject in watershed management, particularly in large forested watersheds ( >  1000 km2). In this study, we selected two large forested watersheds (Pingjiang and Xiangshui) located in the upper reach of the Poyang Lake watershed, southeastern China (with an area of 3261.4 and 1458 km2, respectively), along with long-term data on climate and hydrology (1954–2006) to assess the effects of large-scale reforestation on streamflow. Both watersheds have similar climate and experienced comparable and dramatic forest changes during the past decades, but with different watershed properties (e.g., the topography is much steeper in Xiangshui than in Pingjiang), which provides us with a unique opportunity to compare the differences in hydrological recovery in two contrasted watersheds. Streamflow at different percentiles (e.g., 5, 10, 50 and 95 %) were compared using a combination of statistical analysis with a year-wise method for each watershed. The results showed that forest recovery had no significant effects on median flows (Q50%) in both watersheds. However, reforestation significantly reduced high flows in Pingjiang, but had limited influence in Xiangshui. Similarly, reforestation had significant and positive effects on low flows (Q95%) in Pingjiang, while it did not significantly change low flows in Xiangshui. Thus, hydrological recovery is limited and slower in the steeper Xiangshui watershed, highlighting that watershed properties are also important for determining hydrological responses to reforestation. This finding has important implications for designing reforestation and watershed management strategies in the context of hydrological recovery.

Short summary
In recent decades, limited research has been conducted to examine the role of watershed properties in hydrological responses in large watersheds. Based on pair-wise comparisons, we conclude that reforestation decreased high flows but increased low flows in the watersheds studied. Hydrological recovery through reforestation is largely dependent on watershed properties when forest change and climate are similar and comparable. This finding has important implications for designing reforestation.