Author: Philippe Amstislavski
Institution: State University of New York
Summary: The major aim of this effort is to demonstrate the utility of integration of the remotely sensed imagery data, acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors to detect the temporal and spatial changes in the geographic distribution and area of surface water. The current effort focuses on the coastal areas of St. Lawrence Island. As a PacMARS data product it provides an example of how the implemented methodology can be applied to detect and map changes in coastal open water areas for the period of 2000 to present in all coastal area within the PacMARS study area, from Saint Lawrence Island and along the coastal shelf of the Bering, the Chukchi and Beaufort Seas.
The current hydrological data set is for the two years (2003 and 2012). It is useful in analyzing the change in the coastlines and coastal water bodies (lakes and streams), critical to the human activities related to the subsistence lifestyles on the Island. Note that we considered only the water surfaces showing an occurrency (i.e. number of water detections divided by the number of available observation) above 35% on an annual basis.
In addition to the grids representing monthly detections for the 2 years of data (2003, 2012) also included 2 shapefiles (2003 and 2013) that dikotomize surface into detected ground and water areas. In the attribute table of each of the shapefiles there is a variable GRIDCODE that has 2 possible values -- 1 for water and 0 for ground at the Please contact Philippe Amstislavski for a more detailed explanation the the mapping process. We considered only the water surfaces showing an occurrency (i.e. number of water detections divided by the number of available observation) above 35% on an annual basis.
The data is tarred up in a file called amstislavski_pacmars.tgz. The
directory tree structure in the tar file is as follows: