Depositing process of check dams on loess plateau in Northern Shaanxi Province

As an important engineering measure, check dam is of significance in harnessing soil and water loss in hilly and gully region on the Loess Plateau. The optimal distribution, relative stability, the warped farmland benefit of the check dam system and so on were paid much attention to in recent years, but a little on depositing process until now. By investigating check dams on the Loess Plateau, digging soil profiles of typical check dams, measuring the thickness of each layer and using reservoir storage-capacity curve, the depositing thickness of each layer for the typical check dams on Loess Plateau in North Shaanxi Province was obtained. Based on the theory of sediment yield produced by storm and the rainfall data of depositing process, the corresponding erosive rainfall of each depositing sediment layer was determined in reverse. The relationship between depositing sediment of each layer and the indexes of corresponding erosion rainfall event was established. It was shown by the analysis that the relationship between depositing sediment and rainfall erosibility(R) was in a form of power function, the relationship between sediment deposition and the maximum rainfall intensity within thirty minutes(I₃₀) was established as an exponential function. The relationships mentioned above were satisfactory, which was validated by F-test.