Answer 
I’m pretty sure it’s all of the above 
Explanation
        
             
        
        
        
Answer:
Soil erosion causes siltation in rivers, dams, etc. In some areas, huge river deltas are formed (such as River Nile delta) because of soil erosion. Such places are good for agriculture but not good for urbanization. However, some people do not care about it, they just want to construct buildings on alluvium type soils.