Laserfiche WebLink
~,,~ <br />o ~~~~ <br />satellite images. The Contractor will conduct a peer review of the CU Contractor's (and their <br />subcontractor(s)) ET estimates. This will include review of approach and methodology, analysis and <br />results, and a review of the CU Contractor's stated limitations, conclusions and recommendations. <br />The peer review will be conducted through review of written materials produced by the CU <br />Contractor, and via meetings and telephone discussions with the CU Contractor. Some specific and <br />targeted literature review also will be conducted. <br />89.10 Mapping of Water Features. Multidate satellite images were used in mapping irrigated lands and <br />crop types for the SPDSS study area for the year 2001. These same images will be used to map the <br />extent of water features using techniques similar to those for determining irrigation status with <br />threshold NDVI values. For mapping water bodies, the infrared Landsat image bands are particularly <br />effective because infrared energy is mostly absorbed by water (Hoffer, 1978). Gao (1996) developed <br />the Normalized Difference Water Index (NDWI) for determination of Vegetation Water Content <br />(VWC) based on physical principles. NDWI increases with vegetation water content. The difference <br />NDWI -NDVI can also be used for mapping open water bodies (Gond et al. 2001). NDWI can be <br />used in combination with NDVI in classification models to detect and delineate water features. <br />NDWI will be computed from the 2001 Landsat imagery and used with verification data derived <br />from known water-bodies to map water bodies in the; entire SPDSS study area. The multidate imagery <br />and NDWI will be used to minimize the effects of i~eatures on single-date satellite images including: <br />clouds and other atmospheric influences; the varying extent of water surface area in irrigation <br />reservoirs; and, vegetation around the margins of water bodies. In addition, land cover maps <br />developed by the Contractor under Phase 1 and 2 will be used with analysis of satellite imagery and <br />for validation of results. <br />Deliverables: <br />89.7 Update of technical memorandum, prepared originally under Phase 1 & 2, describing the entire land <br />classification process including satellite imagery and other data, image processing and classification. <br />The ground truth data will be described and the classification accuracy assessment will be updated to <br />include Water Districts mapped during Phase 3. <br />89.7 The following data and information generated under various subtasks of Task 89 will be provided <br />for the South Platte and North Platte River basins. Products for Districts 1, 2, 3, and 64 were <br />provided in Phase 1 & 2; the remainder of the study area will be produced under this Phase 3 and <br />integrated with prior products for a series of single, :Final products far the entire SPDSS study area. <br />Plots <br />1. Irrigated field polygons <br />2. Ground truth plots <br />3. Crop types for irrigated lands <br />4. Draft maps containing review notes from water commissioners, districts and/or water <br />users <br />Raster Files <br />1. Classification of irrigated lands and crop type in raster format <br />2. Interim files for verification of results, such as Normalized Difference Vegetation <br />Index (NDVI) <br />Shape Files <br />1. Irrigated field, polygons <br />2. Ground truth plot locations and attributes <br />3. Crop type for irrigated fields <br />3 <br />