J.L. Smith 2001 Version 1.0 remote-sensing image Reston, Virginia U.S. Geological Survey https://water.usgs.gov/lookup/getspatial?etunit Laczniak, Smith, Elliott, and DeMeo 2001 Water-Resources Investigations Report 01-4195 Reston, Virginia U.S. Geological Survey https://pubs.usgs.gov/wri/wri014195/ The raster-based classification of evapotranspiration (ET) units is for nine major discharge areas in the Death Valley regional flow system. The ET units delineate general areas of similar vegetation and soil-moisture conditions. Classifications were derived from Landsat Thematic Mapper imagery data acquired June 13, 1992; Sept. 1, 1992; and June 21, 1989. The data set was created to delineate the aerial extent and quantify acreage of the different ET units found within the many major discharge areas of the Death Valley regional flow system. Introduction The raster-based classification of ET units within the major discharge areas of the Death Valley regional flow system determined from Landsat Thematic Mapper (TM) imagery data acquired June 13, 1992, Sept. 1, 1992; and June 21, 1989. Background information on classification procedures can be found in American Society of Photogrammetry (1983). Except for Sarcobatus Flat, all discharge areas were classified using the 1992 TM imagery. An accurate classification of Sarcobatus Flat could not be attained from 1992 TM imagery because of extensive cloud cover over the area. Instead, Sarcobatus Flat was classified from TM data acquired June 21, 1989. Reviews The final classification of ET units within each major discharge area was checked for consistency and accuracy during data processing. Two external reviews were done. The reviewers were asked to check metadata and other documentation files for completeness and accuracy. Reviewers also were asked to check the topological consistency, tolerances, projections, and geographic extent. Related_Spatial_and_Tabular_Data_Sets The Landsat entity identification numbers for the two June 13, 1992 scenes, which were used to classify ET units throughout most of the discharge areas in the Death Valley regional flow system are LT5040034009216510 and LT5040035009216510. The entity identification number of the June 21, 1989 scene, which was used to classify ET units in Sarcobatus Flat, is LT5040034008917210, and of the Sept. 1, 1992 scene, which was used in addition to classify Ash Meadows, is LT5040035009224510. In this documentation, under Spatial_Domain, the coordinates given represent the extent of a combined TM image. The combined image was generated by mosaicking the two June 13, 1992 TM scenes. Under Spatial_Data_Organization_Information, the Row_Count and Column_Count are pixel counts based on the combined TM image. Nine areas of ground-water discharge were classified. These discharge areas and their given ArcInfo grid names are Ash Meadows, etunit_am; Chicago Valley, etunit_cv; Franklin Lake, etunit_fl; Franklin Well, etunit_fw; Oasis Valley, etunit_ov; Sarcobatus Flat, etunit_sf; Shoshone area, etunit_sa; Stewart Valley, etunit_sv; and Tecopa area, etunit_ta (includes California Valley and the Resting Spring area). A table describing each area follows. The boundaries are given in Universal Transverse Mercator (Zone 11) coordinates. The row and column counts given are based on 18 meter pixels. >--------------------------------------------------------------- > Grid Row Column West South East North > Name Count Count Boundary Boundary Boundary Boundary >--------------------------------------------------------------- >etunit_am 2068 1646 548630.00 4016213.00 578258.00 4053437.00 >etunit_cv 561 263 572090.43 3979129.12 576824.43 3989227.12 >etunit_fl 656 282 553199.89 4009055.15 558275.89 4020863.15 >etunit_fw 340 388 544386.83 4027209.97 551370.83 4033329.97 >etunit_ov 1556 1167 510666.66 4078337.52 531672.66 4106345.52 >etunit_sf 1345 1420 487910.10 4107068.27 513470.10 4131278.27 >etunit_sa 585 151 565211.96 3973515.00 567929.96 3984045.00 >etunit_sv 844 858 572004.20 3998813.15 587448.20 4014005.15 >etunit_ta 1050 1153 566305.22 3955508.14 587059.22 3974408.14 >--------------------------------------------------------------- References American Society of Photogrammetry, 1983, Manual of remote sensing: The Sheridan Press, 2440 p. Beverley, A.M., and Penton, P.G., eds., 1989, ELAS, Science and Technology Laboratory Applications Software--Vol. II, User Reference: National Aeronautics and Space Administration, Science and Technology Laboratory Report 183, [unpaginated]. Chavez, P.S., 1989, Radiometric calibration of Landsat Thematic Mapper multispectral images: Photogrammetric Engineering and Remote Sensing, v. 55, no. 9, p. 1285-1294. Laczniak, R.J., DeMeo, G.A., Reiner, S.R., Smith, J.L., and Nylund, W.E., 1999, Estimates of ground-water discharge as determined from measurements of evapotranspiration, Ash Meadows area, Nye County, Nevada: U.S. Geological Survey Water-Resources Investigation Report 99-4079, 70 p. U.S. Geological Survey, 1989, Landsat Thematic Mapper imagery: Sioux Falls, S.D., U.S. Geological Survey. U.S. Geological Survey, 1992, Landsat Thematic Mapper imagery: Sioux Falls, S.D., U.S. Geological Survey. Notes Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this data set has been used by the U.S. Geological Survey, Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data and related materials. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in non-proprietary form, as well as in ArcInfo(R) format, this metadata file may include some ArcInfo-specific terminology. Users should exercise caution and judgment in applying these data, and be aware that errors may be present in any or all of the digital image data. If errors are encountered in this data set, it will be appreciated if the user would pass this information to the Metadata_Contact. 19890621, 19920613, and 19920901 The classification is appropriate only for the date of the imagery. Complete None planned -117.14110287 -116.02616289 37.3203447 35.73952569 USGS Thesaurus evapotranspiration ET classification inlandWaters ISO 19115 Topic Category geoscientificInformation inlandWaters environment USGS Metadata Identifier USGS:ac575a6f-00f1-4816-a538-ea0bf544c71c Geographic Names Information System Nevada southern Nevada eastern California Ash Meadows California Valley Chicago Valley China Ranch Death Valley Franklin Lake Franklin Well Oasis Valley Resting Spring Sarcobatus Flat Shoshone Stewart Valley Tecopa None The data are derived from copyrighted data provided by EOSAT Corporation. No use constraints apply. Users should exercise caution when using these data. Use with similarly scaled data. Acknowledgment of the U.S. Geological Survey and the U.S. Department of Energy would be appreciated in any products derived from these data. J.L. Smith U.S. Geological Survey Hydrologist mailing and physical address

333 W. Nye Ln.

Carson City NV 89706 USA 1-888-275-8747 (775) 887-7629 jlsmith@usgs.gov https://pubs.usgs.gov/wri/wri014195/text/figures/figure06.htm Illustration of data set htm Compilation of this data set and the associated metadata was done in cooperation with the U.S. Department of Energy, Nevada Operations Office. IRIX64, 6.4, IP27 UNIX ArcInfo version 7.2.1 See Entity_Attribute_Information See Explanation. Where present an explanation is used to describe each attribute defined in the Entity_and_Attribute section. Not applicable for raster data. Complete For geometric corrections, 72 control points evenly distributed throughout the image generally are collected. First order global polynomial models were used. During geocorrection model evaluation, some control points are dropped but others in the immediate area are collected as replacements. Maps at a scale of 1:24,000 were used for initial control point collection. These procedures produced acceptable models for TM data geocorrection. In some areas, more than a one- or two-pixel error has been observed as compared with Digital Line Graph (DLG) data. Distortions in the mountainous areas probably were greater than one pixel due to relief. 25.0 meters Overall root-mean-square (RMS) errors of the geocorrection models were less than one pixel and generally ranged from 15 to 25 meters in the x and y directions. Some individual control points may have RMS errors approaching 40 meters. U.S. Geological Survey (USGS) 19890621 and 19920613 remote-sensing image Sioux Falls, SD 67198 USGS CD-ROM 19890621 and 19920613 ground condition Landsat TM The Landsat TM was processed using the National Landsat Archive Production System (NLAPS) systematic correction. The TM data are converted to NASA ELAS format (Science and Technology Laboratory Application Software; Beverley and Penton, 1989). Data quality is assessed, statistics are collected, classification is produced, and geometric corrections are performed using ELAS. Preprocessing of the TM data included mosaicking the two scenes together. Since the scenes were the same date, a common point was found in the overlap area and the scenes were copied together into an output file. The imagery was then converted to ArcInfo(R) GRID format for analysis and integration with other geographic information. An unsupervised approach was used to identify the unique spectral responses present within the imagery. Training statistics were collected in each of the major discharge areas (areas of significant ground-water ET). Additional training statistics were collected over the entire data set using an algorithm that searched for homogeneous areas by sliding a three-by-three pixel window across the image. A maximum-likelihood classification was used to associate individual pixels with spectral responses developed by the training statistics. Through field observations and the analysis of the training statistics, a final ET-unit classification was interpreted. Statistics in each initial spectral response showed similar patterns. Initially the training statistics were analyzed and grouped into several clusters. Atmospheric and radiometric correction of the statistics were made using the programs TMHAZE and TM2REF developed and described; Chavez (1989). Maps of the initial classification at a scale of 1:24,000 were made for field trips. Field trips included taking photographs of selected sites which were documented on standard forms or in a field notebook. Precision Light-weight Global Positioning Systems (GPS) Receiver (PLGR) was to locate field sites. An outer boundary around each major discharge area was mapped during field visits. The boundary was located to include phreatophytes and moist soil areas within the major discharge area. The boundary focused the analysis on the major discharge areas and eliminated potential confusion between phreatophytes and lush desert and mountain vegetation during the final classification procedure. Clusters were regrouped as necessary to reflect any noted field observations prior to a final ET-unit classification. In addition to the June 13, 1992, TM data, the classification of Ash Meadows used TM data acquired Sept. 1, 1992. The procedure differed from that presented above in that it combined two independent classifications, each derived from TM data acquired on a different date. One date represented late spring conditions and the other represented fall conditions. The procedure is described in detail in Laczniak and others (1999). The Sarcobatus Flat area was classified using June 21, 1989 TM data. An accurate classification of Sarcobatus Flat could not be attained from the June 13, 1992, TM imagery because of intense cloud cover throughout the area. Instead a June 21, 1989 TM scene was processed as described above to produce separate training statistics from which the final classification was performed. Landsat TM 1995-97 Raster grid cell 13955 11270 Universal Transverse Mercator 11 coordinate pair 18.0 18.0 Meters North American Datum of 1927 Clarke 1866 6378206.4 294.98 grid cell grid cell used for ET unit value ArcInfo(R) GIS software VALUE ET unit value Author 0 10 A value of 0 indicates that a pixel was unclassified. A value greater than 0 indicates that a pixel was classified as an ET unit. Ten ET units were identified within the major discharge areas of the Death Valley regional flow system. Each ET unit is designated an integer from 1 to 10 as follows: >0 - no significant ET, >1 - open water, >2 - submerged aquatic vegetation, >3 - dense wetland vegetation, >4 - dense meadow and forested vegetation, >5 - dense to moderately dense grassland vegetation, >6 - sparse grassland vegetation, >7 - moist bare soil, >8 - sparse to moderately dense shrubland vegetation, >9 - sparse woodland vegetation, >10- open playa. The code in VALUE is a categorical number created from the classification procedure. The VAT file of the ArcInfo grid also contains the attribute COUNT which is the number of pixels having an assigned VALUE. The ArcInfo grid also includes a statistic file (ETUNIT_[area].STA) which contains the attributes MIN, MAX, MEAN, and STDV, where MIN is the minimum of VALUE, MAX is the maximum of VALUE, MEAN is the mean of VALUE, and STDV is the standard deviation of VALUE. These attributes have limited relevance in that they summarize the statistics of categorical data, and therefore, are not included in any non-proprietary digital data sets. >ETUNIT_[area].VAT: > >COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME > 1 VALUE 4 10 B - > 5 COUNT 4 10 B - > > >ETUNIT_[area].STA: > >COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME > 1 MIN 8 15 F 3 > 9 MAX 8 15 F 3 > 17 MEAN 8 15 F 3 > 25 STDV 8 15 F 3 > none U.S. Geological Survey Michael Ierardi IT Specialist mailing

445 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) mierardi@usgs.gov Although this data set has been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Export Full coverage zipped 1 https://water.usgs.gov/GIS/dsdl/etunit_data.tgz Export Full coverage zipped 1 https://water.usgs.gov/GIS/dsdl/etunit_meta.tgz None. This dataset is provided by USGS as a public service. 20201117 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing

445 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) mierardi@usgs.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998