I have got problem in getting area from the ROI. currently,I am estimating the lake area with time using band threshold to ROI tool.however the area shown under option- report area of ROI is all the same.Actually the lake shrinks & gets dry with time. how can get the area estimate with in the ROI generated? I am not sure whether I am doing wrong with the ROI( assumed maximum lake area extent) using polygon or polyline. regards