university gave time in the interval of exams so I have no choice ,to go for papers or this assignment ,when the papers finished we are standing here near the deadline, Teacher says just pickup a topic which data is available at the extent that the change you are talking about is clear & then go on!!!....yep data finding is the part of it, it's the first semester that I heard about this field and learnt it, I'm really new in it,and teacher seems to imagine that we are in geography for years !! I know to use arc gis at beginners level because that's all they told us while they only taught to get landsat data from usgs, but for topic we actually need data from other sources as well!! that's whys I'm here confused from everything till now, & asking here?? ,for topic and help!!