Chosen Hekouzhen Longmen region as research area

the study focused on the calculation of re-gional sediment reduction by engineering control and tillage measures(E

T). Approximately 1% of the total area was surveyed in grids to obtain detailed information regarding engineering controls and tillage. Com-bined with existing research findings

the potential and actual amount of soil erosion modulus(Arand A

re-spectively) were calculated for the surveyed blocks of land. Using A/A' as the value of grid where field sur-vey was conducted

regional factors E and T were then obtained as the basis to estimate sediment yield and reduction in sediment yield by engineering projects and tillage practices. The results show that the total area of the eroded land and the spatial distribution of the soil erosion intensity were consistent with the existing research results. The regional soil erosion modulus was estimated as high as 4 004 t/km2·a) and total sedi-ment yield of the study area reached 4.54×108 t/a. Engineering projects and tillage practices possibly con-tributed reduction of 8.00×107 t/a to the total sediment yield. The eroded land concentrated in the middle area of the loess hilly and gully region

including counties of Jiaxian

Linxian

and Shenmu

etc.