*3.4. Soil Erosion Estimation under Di*ff*erent Scenarios*

The scenarios were developed to estimate the further reduction in soil erosion associated with land use change under soil conservation structures. The scenarios were developed according to the scientific literature of land use and vegetation cover importance to assess soil erosion and farmer's common cropping practices in the study region. Vegetation cover increases the infiltration rate [70], reduces the erosive velocity of surface runoff, and plays a key role in resisting water erosion. A trivial variation in vegetative cover can produce considerable effects in overland flow [71]. Vegetation cover is a key factor in controlling and reducing surface runoff and water erosion on agricultural land [72].

The analysis of the various scenarios (Table 4) revealed that the sediment yield level was higher in S1 and S2 than in S3 and S4. This indicated that the sediment yield level is higher on agricultural land than on fallow land with crop residue. In the comparative analysis of S1 and S2, the average sediment yield decreased to 1.25 t ha−1, whereas in S3 and S4 (fallow land with crop residue), the average sediment yield decreased to 0.85 t ha<sup>−</sup>1. The results disclosed that land use change facilitates sediment yield reduction, in addition to soil conservation structures.

**Table 4.** Effect of different scenarios on sediment yield reduction (S represents land use scenario and SY is the sediment yield i.e., the amount of sediment received at the outlet of each watershed in a given period of time).


Notably, a visual observation of the various structures revealed that the effects of the structures on soil erosion control generally extended to a 4–5 m radius from the center of the structure crests during high flow seasons; the water was accumulated and sediment was deposited upstream of the structures.
