Lab 2

Part 1

The purpose of this part of the lab is to delineate the watersheds in the Adirondack Park in northeastern New York. Watersheds represent the area of land that all surface water is connected. Delineating these such watersheds allows for watershed managers to better monitor the quality and the quantity of water found within them. For the purpose of this lab the Adirondack shapefile was downloaded from the New York State GIS Clearinghouse (http://gis.ny.gov). The hydrology data was acquired from the Cornell University Geospatial Information Repository (http://cugir.mannlib.cornell.edu/index.jsp). The DEM was retrieved from ArcGIS Online.

Once the data was brought into ArcMap, the data needed to be preprocessed. All the data was placed into the Universal Transverse Mercator (UTM) Zone 18N NAD 1983 projected coordinate system. To begin, a 20 kilometer buffer the Adirondack boundary so that DEM could be processed more smoothly. Then the hydrology layer was clipped by the Adirondack shapefile, leaving only the hydrology in the park. Next, the DEM was clipped by the buffered Adirondack boundary.

Once all the preprocessing was completed, the watershed delineation process could be started. This was done in a series of steps. To begin, the a flow direction raster was created and the sinks were then filled (sinks disrupt the flow of water and therefore would negatively effect the waterflow modeling). Once the sinks were filled, another flow direction model was created a flow accumulation raster was created, leaving small stream channels. These small channels were then given a threshold of 50,000 cells. Then the streams were then connected so that the watersheds could then delineated (Figure. 1).

(Figure. 1)  Adirondack Watershed Map

Part 2

The second part of this lab was to use model bluespots (depressions prone to flooding because of a lack drainage) in the Denmark City of Copenhagen. Due to extreme rainfall events such as cloudbursts, the city has experienced large amounts of flood damage as a result. To identify areas in danger of flooding a model was run (Figure. 2) that identified bluespots and then intersected them with buildings (Figure. 3). After running the first model, a second model was run. This second model not only located bluespots but calculated the volume of these spots so that the bluspots can be ranked by their susceptibility for flooding (Figure. 4).

(Figure. 2) Model used to find bluespots and intersect them with buildings

(Figure 3) The map above shows bluespots and the buildings that are in contact with them

(Figure. 4)The Map above shows buildings that are touching bluespots as well as showing the drainage capacity of the bluespots

The map above shows the buildings that are at most risk of flooding in Genofte

The map above displays the relationship between watershed area and the bluespots found within them

The map above shows roads and rail ways that are least likely to be affected by flooding