Lab 2: Watershed Analysis

Introduction
The purpose of this lab was to gain an introduction into watershed analysis. The data was acquired, process, and watersheds were delineated, and questions regarding the results were answered in the initial report.

The data used is shown below.

Methods
The project is broken into three steps: data collection, data processing, and watershed delineation.
 1) Data Collection
-The data was downloaded from the sources above, unzipped, and brought into ArcMap.

2) Data Processing
-A buffer was set around the park boundary at 20km.
-The hydrology was then projected to match the park boundary.
-A 30 arc-second DEM of North America was then added as a basemap, which was clipped to the size of the park buffer and projected to match the other data.
The result is shown in Figure 1, which includes the DEM, park boundary, and hydrology.

Figure 1: The result after processing the data.

3) Delineating Watersheds
-Flow direction was calculated.
-The sinks were filled with values ranging from approximately 21 - 1469.
-Flow direction was then recalculated.
-Flow accumulation was then determined.
-A source raster was then created using 50,000 as the raster threshold.
-Stream link was used next.
-Watershed tool was then used to delineate watersheds and that was clipped to the size of the park.
Figure 2 shows the result of the watershed delineation.

Figure 2: The watersheds within the park boundary. 

Results

Figure 3: The map showing the watersheds within the Adirondack park boundary.  It can be observed that the water moves from North to South, and the map shows the areas for each watershed.  The number of watersheds depends on several criteria when processing the data and other aspects of the delineation process.  

Conclusion
This method of delineating watershed analysis could be useful for modeling, locating stream sources, identifying streams, etc.  The size and number of watersheds can be determined by choosing the characteristics that pertain the specific project at hand.  Overall this was a good introduction to using the watershed tools and creating a watershed analysis.