Effects of Soil and Water Conservation Measures on Hydrological Regime in Loess Plateau

摘要

Since the 1950s the hydrological regimes have been significantly influenced by anthropogenic factors such as large scale soil-water conservation measures in the Loess Plateau. While these measures have reduced soil erosion, they also result in noticeable changes in the stream flow regime. In this paper the changes of stream flow regime were evaluated in the Chabagou catchment. The results indicated that a noticeable inflexion of stream flow occurred in 1978 due to conservation measures. Average annual stream reduces by 30% compared with the period before 1978. Reductions in annual stream flow were associated with interannual and intraannual variability in stream flow. Stream flow in wet season appears to be the main factor responsible for the decrease in intraannual variability. In addition, the hydrological regime of the catchment was changed consistently with the up and down progress of sediment-trapping dams.