EVSC 362: GIS Methods - Summer 2008

Habitat Preference of Colonial Nesting Birds on Northern Hog Island: 1976-1978

This is a fairly short and easy exercise. You goal is to determine the following based on the available data:

1) What species of colonial nesting birds choose to nest on northern Hog Island during the years 1976-1978? (common names are fine.) How many adults of each species were present and counted on north Hog during these three survey years? (total #.)

2) Judging by the location of the bird colonies relative to features observable on the 1974 air photo, what kinds of habitats do the different groups of birds prefer to nest in (beach, salt marsh, shrubs, grassy dunes behind the beach, mud flats, etc.)

3) Were the locations that the birds chose to nest in during 1976-1978 still suitable nesting habitat in 1994? If any locations by 1994 were no longer suitable, what seems to have changed?

Note that both the 1994 DOQQs and the 1974 image are false-color infrared aerial photos. This means that while water areas will show up as blue or dark (or muddy colored if very shallow or with a lot of turbulence), and highly-reflective bare sand of the beach and dunes will show up white, the lush dark green areas of the shrub thickets will actually show up as bright red areas. In the 1994 DOQQs the grasslands and brackish marshes (east of the shrubs and in the swales between the shrubs) and marshlands (the expansive areas on the west side of the island) should show up as pale green and dark green, respectively, but will be more variable in color and not quite as easy to distinguish in the 1974 photo due to the quality of the photo.

The data you have to work with are:

A) "birds6.shp" - dataset containing center points of the bird colonies, plus other associated attribute data. Data is in UTM zone 18 meters NAD83.

B) QuinbyDOQ_NE.sid, QuinbyDOQ_NW.sid. QuinbyDOQ_SE.sid - three rectified USGS DOQQ aerial photos in same datum/coordinate system as above. Acquisition date=1994.

C) "Nhog74_2.tif" - unrectified air photo of north Hog taken in 1974. Image has no real world coordinates. You will have to georectify this image to answer the questions.

D) "nhog_gcp_lines.shp" - a shapefile of lines to help you choose good obvious control points to use to rectify the #C image above. Display these overtop of the DOQs to see creek intersections, raised shrubby hummock "islands" in the marsh, etc. that should work well for you to use. If you see where these lines line up correctly on the 1994 images, then you'll know where they are suppose to line up on the 1974 image.

Hand in:

Answer the questions (written out as a short report) and make me a presentation quality map (i.e., still with all the info that makes a good useful map) of the bird colony locations drawn overtop the 1974 photo. That's it.