Advanced GIS Lab6

Methods

The five parts were conducted in the lab. In the first part, I used the Mosaic to new raster for combining two DEM tiles after downloading DEMs. During the projecting elevation data, I used the Bilinear resampling technique. In the second part, several sequence tools conducted for watershed delineation. To be specific, the Fill tool for repairing holes in the DEM, the Flow Direction tool for calculating the direction of flow, and the Flow Accumulation tool for calculation of how many cells would drain. Before making a watershed area, you have to choose a pour point using the create a point feature, and this point is an outlet of the watershed. In the third part, I found a break value to create two classes in the flow accumulation layer. I selected 2,000 as a flow accumulation threshold value and reclassified it that less than 2,000 is NoData, and over 2,000 is 1. In the fourth part, I calculated the stream order tool after using the clip tool and found there are 5 orders in the watershed. Finally, I created the profile graph on the map by the interpolated line in the 3D Analysist tool and created a contour.  

The total length of stream (395.95km) 

Contour