Assertion: slope | /r/HasProperty | steepened by man
Facets:
Source sentences:
text: For this reason, the areas of moderate and high incidence of landslides are confined mostly to the valley walls of the Missouri River and to its principal tributaries, although the intervening flatter areas show abundant signs of very shallow disturbance of soil and weathered bedrock and are susceptible to landsliding when slopes are steepened by man or nature.