displaced - v. to force (people or animals) to leave the area where they live

tendency - n. a quality that makes something likely to happen or that makes someone likely to think or behave in a particular way

external - adj. located, seen, or used on the outside or surface of something

mud - n. soft, wet dirt

impact - n. a powerful or major influence or effect

vulnerability - n. easily hurt or harmed physically, mentally, or emotionally

tributaries - n. a stream that flows into a larger stream or river or into a lake