Using watem/sedem to configure catchment soil conservation measures for the black soil region, Northeastern China

Abstract

In recent years, to combat soil erosion, large-scale soil conservation measures have been implemented in the world. Evaluation of the integrated catchment management is urgently required. In the present study, soil erosion and sediment yield under 24 scenarios were predicted, based on the water and tillage erosion model and sediment delivery deposition model (WaTEM/SEDEM). The current catchment management was not ideal, with a catchment soil loss rate (SLR) of 599.88 t km−2 yr−1 and a sediment yield of 240.00 t km−2 yr−1. The catchment management with contour tillage on <3° slopes, hedgerow planting on 3°–5° slopes, terracing on 5°–8° slopes, and forestation on >8° slopes with trenches along the forest and dams in gullies was the best catchment management to control soil loss, with catchment SLR that was less than the tolerable value of 200 t km−2 yr−1. However, the SLR on the <3° slopes was still higher than the tolerable val-ue. It is not enough to control soil loss by only implementing contour tillage measure on <3° slopes, and other measures should be further implemented on these slopes. In gullies, more measures should be implemented to prevent sediment flowing out of the catchments, in Northeastern China.