Lab 3 - Watershed Analysis

This week we moved on to watershed analysis. Maybe because my sister is in the watershed science department in her PhD program, or maybe because I walked my husband through the steps of the lab so he could give me some insight to some math calculations, I enjoyed this lab. I won't go so far as to say I understand it a lot better than suitability analysis and corridor analysis, however trying to explain a process to someone unfamiliar with it always helps define our knowledge a little more.

The lab basically walked me through stream and watershed delineation, culminating with the map included here comparing two watersheds and two stream networks. I practiced processing a DEM for sinks and filling those lower elevation (potential error) areas in, creating a flow direction raster, flow accumulation grid, setting a threshold value for to define streams, watershed and basin delineation, stream order, and pour points. A lot of tool and raster production! 

The final map used an existing stream network and watershed, which I overlaid with a stream network and watershed that I delineated. I then considered discrepancies between the two, such as total drainage area or the details in the network based on my stream accumulation threshold values. The biggest challenge in the lab, which isn't so different from the others is understanding the mathematical processes that produce the results so I can better analyze the results. Answering the questions about the results is definitely the area of challenge for me right now. All in due time.

Watershed and stream network comparison for drainage areas within Kauai, HI.