Remote Sensing
INTERA has applied remote-sensing based techniques to evaluate irrigated acreage and surface-water depletions over large areas of the southwestern U.S. for a variety of state and federal agencies. Using the existing archive of available Landsat data, we are able to evaluate land cover, irrigated acreage, and depletions over a historical period stretching back to the early 1970s. For periods prior to that, we use aerial photography from a variety of sources.
The use of satellite data and remote-sensing based techniques enables us to conduct present-day and historical analyses of large areas on the order of hundreds of thousands of acres, allowing analysis of entire irrigation districts or even entire states.
INTERA's analysts not only understand the data sets required to conduct acreage and depletion analysis, but also the underlying irrigated practices and institutional frameworks, creating the depth of expertise needed to solve the complex water rights issues associated with irrigation practices in the western U.S.
Our remote-sensing based methods have been used in numerous water resources and water-rights analyses including evaluation of temporal (historical) trends in irrigated acreage, developing irrigated acreage estimates for regional groundwater modeling, and estimating historical irrigated acreages in lieu of field surveys to support water rights and planning for reservoir releases.
Our remote sensing services include:
Remote-sensing based analysis of irrigated acreage
- vegetation index (NDVI) based analysis of regional irrigated acreage
- land cover analysis
- evaluation of depletions using NDVI- or land cover-based estimates of irrigated acreage
Digital analysis of historical aerial photography
- scanning and digitizing of historical aerial photography
- georectification of digital aerial photography
- heads-up digitizing of field boundaries
- land cover delineation
- irrigated acreage estimation using field-boundary polygons
GIS Development and Analysis
- integration of satellite and digital aerial photography data with other map-based data
- automated analysis and summation of irrigated acreages and other land-cover types
- polygon masking of riparian, urban, and other areas to exclude them from the analysis
Field surveys
- GPS- and GIS-based field surveys to confirm acreage estimates
- crop type identification
- multi-seasonal analysis
