GIS and Remote Sensing

Aerial view of a farm.

The Columbia Plateau of eastern Washington, northeast Oregon, and the Idaho panhandle includes soils that are susceptible to wind erosion. Urban areas of the region have experienced exceedances of allowable airborne dust as defined by the 1990 Clean Air Act; such dust is regulated as PM10, a mass concentration measurement including particles of 10 micrometers and smaller in diameter. The Columbia Plateau PM10 Project (CP3) was undertaken to address this regional air quality problem. Modeling of dust generation and transport was central to the concept of the project, and this modeling required development of appropriate data layers to be used as model inputs. Remote Sensing (RS) and Geographic Information System (GIS) tools were used to create necessary data layers describing geophysical and vegetative aspects of the domain ctydem of the Columbia Plateau PM10 Project. These layers include topography, soils, vegetative cover including agricultural land uses, and miscellaneous political boundaries. These web-pages present the study domain, discuss the sources of data, and show the resulting data layers provided to CP3 modelers.

One fundamental requirement for the CP3 modeling effort is a land use or vegetative cover map. The land use requirement was approached through use of Bi-weekly Composited Advanced Very High Resolution Radiometry (AVHRR) imagery from USGS and the USDA. The basic procedure used to generate a land use data layer from the 1990 USGS/USDA Bi-weekly Composited AVHRR is discussed in “Source Area Studies Using AVHRR and GIS”, Vaughan and Frazier 1995, and resulted in the CP3 Vegetative Cover (Land Use) Map (CP3 Vegetation).

AVHRR Satellite Imagery for Vegetative Cover (Land Use) Mapping for CP3

Map of the US.

The above Advanced Very High Resolution Radiometer (AVHRR) derived image for the entire United States illustrates this satellite instrument’s utility for capturing broad vegetative and landscape types. Data from NOAA-11 satellite acquisitions were used along with the associated elevation and hydrological data in developing a CP3 domain land use layer. The NOAA Polar Orbiting Environmental Satellites (POES) collect data using AVHRR instruments. These data were attractive because of 1) their availability throughout a complete time sequence matching appropriate ground data and spanning the growing season throughout the continental US, 2) the approx. 1 km resolution promises reasonable detail for the CP3 landscape with acceptable file storage requirements, 3) extensive background research is available applying AVHRR for landscape characterization.  The AVHRR data used in CP3 were compiled by USGS as biweekly composites of the whole United States. They include five bands: red, near-infrared (NIR), and three thermal bands at 1 km resolution. This resolution was deemed appropriate for regional modeling and suitable to generate broad classes of land cover as required by the modeling effort.  The five bands captured by the NOAA-11 AVHRR instrument are represented by these example composite images from 1990.

AVHRR Imagery Examples for the CP3 Domain

To illustrate the nature of the land use identification, a number of vegetation images are presented next. The following images represent specific vegetative cover conditions as identified from AVHRR images from June and September of 1993.

Topographical Relief

The Columbia Plateau PM-10 Project study area occupies the east-central part of Washington with adjoining areas in Oregon and Idaho. The study area, 400 km East-West by 340 km North-South, was defined according to the coordinates listed in the following table.