A.J. Cohen, A.D. Randall 1998 1.0 map USGS Open-File Report USGS OFR 96-395 Reston, VA U.S. Geological Survey https://water.usgs.gov/lookup/getspatial?ofr96395_eva Two maps, compiled at 1:1,000,000 scale, depict mean annual runoff, precipitation, and evapotranspiration in the part of the United States east of Cleveland, Ohio and north of the southern limit of glaciation. The maps are mutually consistent in that runoff equals precipitation minus evapotranspiration everywhere. The runoff map is based on records of streamflow from 503 watersheds in the United States and southernmost Canada, adjusted to represent 1951-80 and supplemented by records of precipitation at 459 stations. Precipitation at each station was partitioned into point estimates of runoff and evapotranspiration, which were constrained such that the evapotranspiration estimates varied smoothly across the region and decreased with increasing latitude and altitude, and the runoff estimates were consistent with measured runoff from nearby watersheds. A point estimate of runoff was allowed to equal mean runoff in a nearby watershed, or to be somewhat higher (or lower) if a compensating departure from mean watershed runoff could be inferred in distant parts of the watershed on the basis of altitude or regional trends. Then, precipitation contours were drawn to parallel runoff contours but differ from them by the magnitude of nearby estimates of evapotranspiration. These maps may slightly underrepresent mean precipitation and evapotranspiration in areas of high relief because most precipitation stations in such areas are in valleys. These 3 coverages were used to produce Open-File Report 96-395. Additional information about methodology can be found in this report Any application involving the need for digital regional runoff, precipitation, or evapotranspiration values. Possible uses include spatial data layer extraction, clipping, cartographic and illustrative display, estimation of amounts of water available for aquifer recharge, surface-water and ground- water modeling, and other analytical or comparative mapping. Procedures_Used: Author compiled contours as inked lines on the base plotted at 1:1,000,000 scale on scale-stable mylar. The contours were scanned on a Contex 8000 scanner at 200dpi and dumped into an rlc file. This rlc file was imported into PixelTrac software where the raster image was used to produce a vector file in dxf format. The dxf file was imported into ArcInfo and further transformed from a dxf file in scanner units to an ArcInfo coverage in real world coordinates. Rms error for this final transformantion was less than .010. The original source data was in Albers Projection, units meters, parameters 29 30 00, 45 30 00, -96 00 00, 23 00 00. Checkplots on non-base stable materials were used to initially check for accuracy and completeness. 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 Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ARC/INFO format, this metadata file may include some ARC/INFO-specific terminology. unknown Ground Condition Complete None Planned -81.93725272 -67.07902572 46.54184301 40.27605251 USGS Thesaurus evapotranspiration contours in the northeastern United States inlandWaters ISO 19115 Topic Category geoscientificInformation inlandWaters environment USGS Metadata Identifier USGS:d12fbc30-45fb-4160-b13d-7235d87ebb6b Geographic Names Information System Maine westward to Ohio and north of the southern limit of glaciation none Data was compiled at 1:1,000,000 scale. Caution should be exercised when using this data at any smaller scale. Coverage was created using data from 1951-80. Caution should be exercised when using this data for any other time period. Andy Cohen U.S. Geological Survey GIS Specialist (mailing and physical address)

425 Jordan Road

Troy NY 12180-8349 USA 1-888-275-8747 518-285-5601 acohen@usgs.gov https://water.usgs.gov/GIS/browse/ofr19960395_plate2.jpg Illustration of the data set .jpg This coverage is a product of the U.S. Geological Survey's Regional Aquifer-Systems Analysis Program. Windows_NT, 4.0, Intel ARC/INFO version 7.2.1 U.S. Geological Survey 1998 map USGS Open-File Report USGS OFR 96-395 Reston, VA U.S. Geological Survey http://pubs.er.usgs.gov/usgspubs/ofr/ofr96395 The final phase for release of this dataset to the public is USGS review and approval. Criteria used in the review process include positional accuracy and precision with respect to source, contextual accuracy, attribute accuracy, topological consistency, and appropriate metadata. Reviews of this coverage were made by George Casey (USGS Hartford, CT), and Doug Freehafer (USGS Troy, NY) in May 1998. All review comments were addressed. Reviews are on file at USGS Troy, NY. Chain-node topology present. See Attribute_Accuracy_Report: This metadata set for mean annual evapotranspiration and the companion runoff and precipitation data sets (ofr96395_run and ofr96395_pre) are mutually consistent in that they were drawn so that precipitation minus runoff equals evapotranspiration at every location and in that areal distribution of precipitation data influenced runoff contours, and areal distribution of runoff data influenced precipitation contours, as explained by Randall (1996). The runoff contours were drawn first (see ofr96395_run). After some quality control checks and revisions of the runoff map, a map of mean annual precipitation was drawn such that the precipitation contours parallel runoff contours and are consistent with the point precipitation data. Differences between runoff and precipitation on the two maps correspond to evapotranspiration as estimated earlier by partitioning of precipitation at each station into regionally consistent point runoff and evapotranspiration values (see ofr96395_run). Evapotranspiration is shown as 1-inch zones of uniform evapotranspiration rather than as contours because evapotranspiration at each precipitation station was estimated only to the nearest inch during the partitioning process. Average annual evapotranspiration is a statistical concept whose true value at any specific horizontal position can never be absolutely known. The positional accuracy of the companion runoff contours was evaluated statistically by comparison with runoff from watersheds initially excluded from the analysis as explained in ofr96395_run. No comparable test was made for evapotranspiration zones, but the fact that one of three mutually consistent data sets was found to be somewhat improved from previous interpretations reflects favorably on the other two data sets. Quality-control tests were used to detect blunders in drawing or compiling precipitation contours. 1. Evapotranspiration zone boundaries as compiled and plotted by GIS were visually compared on a light table with author's linework. Any departure greater than about 3 linewidths over distances longer than about one centimeter were marked for correction. Localized departures, mostly instances of linear arcs that did not exactly match the author's curved contours, were generally ignored. 2. Geographic Information Systems software was used to create a three dimensional surface from the runoff contours, and a similiar surface from the companion precipitation contours, by the Delauney method of triangulation. These surfaces were resampled to generate lattices having a spacing of 4 miles between lattice points, and runoff was subtracted from precipitation in each lattice block. Discrepancies between the array of evapotranspiration values thus computed and the evapotranspiration zones as delineated by the author enabled several mislabeled contours and minor misinterpretations in placement of contours to be detected. U.S. Geological Survey 1998 map USGS Open-File Report USGS OFR 96-395 Reston, VA U.S. Geological Survey 1000000 mylar separate complete USGS OFR 96-395 (example: contours from Fig. 4, page 25) See Supplemental_Information 1992-1999 First draft of metadata created by acohen using FGDCMETA.AML ver. 1.32 01/11/99 on ARC/INFO data set r:\district_gis\northeast\meteor\1m\ofr96395_eva 19991209 Vector Point 20 String 23 Lambert Conformal Conic 41.25 46.25 -74.25 23 0.00000 0.00000 coordinate pair 103.5011672973 103.5011672973 Meters North American Datum of 1927 Clarke 1866 6378206.4 294.98 This coverage consists of a line coverage with an associated arc attribute table and a point coverage with an associated point attribute table. These points were added after the author had constructed the boundaries (arcs) which differientiate zones of equal mean annual evapotranspiration. Placement of points do not represent zone centroids. They are simply used to identify the evapotranspiration value between arcs. point attribute: Zone = mean annual evapotranspiration, in inches arc attributes: Value1 = evapotranspiration value used for labeling only Value2 = evapotranspiration value used for labeling only 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/ofr96395_eva.e00.gz None. This dataset is provided by USGS as a public service. 20201117 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing

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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