GEOGRAPHICAL RESEARCH ›› 2010, Vol. 29 ›› Issue (3): 397-407.doi: 10.11821/yj2010030002

• Earth Surface Processes • Previous Articles     Next Articles

Effect of artificial sediment sinks on sediment delivery ratio: An example from the Wudinghe River, China

XU Jiong-xin   

  1. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
  • Received:2009-09-21 Revised:2009-10-12 Online:2010-03-20 Published:2010-03-20

Abstract:

As an important measure to reduce the sediment entering the Yellow River, a great number of reservoirs and check-dams have been built in the Wudinghe River basin, trapping huge amount of sediment. As a result, artificial sediment sink formed, which greatly reduced sediment delivery ratio of the river. The influence of artificial sediment sink on sediment delivery ratio is an important issue in fluvial geomorphology, but so far there has been little research devoted to this issue. Based on data from 1956 to 1996 in the Wudinghe River basin, artificial sediment sink, erosion amount and sediment delivery ratio (SDR) have been calculated, temporal variation in these variables has been analyzed, and multiple regression equations have been established. These results show that (1) sediment yield and erosion amount decreased; (2) artificial sediment sink increased to a peak and then decreased; (3) SDR decreased to a minimum and then increased. This indicates that the temporal variation in SDR is mainly controlled by the variation in artificial sediment sink. To reveal quantitatively how the water and soil conservation measures and other factors influence sediment delivery ratio, multiple regression analysis has been conducted. The multiple regression equation shows that SDR increases with the increases in high-flow season precipitation (P6-9), the annual maximum 1-day rain amount (P1), the annual maximum 30-day cumulative rain amount (P30), and the runoff to precipitation ratio (Cr), but decreases with the increases in the areas of land terracing, tree and grass planting (Atfg) and the area of land created by check-dams (Ac). The increase in Ac makes the largest contribution to the decrease in SDR, and the decrease in Cr makes the second contribution. Among the three indices of precipitation, P30 makes the largest contribution, P6-9 the second and P1 the third. In two types of soil-water conservation measures, the effect of Ac on SDR is much larger than that of Atfg.

Key words: water and soil conservation, sediment sink, sediment delivery ratio, sediment budget, Wudinghe River basin