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By selecting one of the four series options shown below, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively, the user will be taken to that map.
By selecting one of the four series options shown below, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively, the user will be taken to that map.
By selecting one of the four series options shown below, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively, the user will be taken to that map.
By selecting one of the four series options shown below, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively, the user will be taken to that map.
By selecting one of the four series options shown below, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively, the user will be taken to that map.
Computers have opened up areas of map projection research which were previously too complicated to utilize, for example, using a least-squares fit to a very large number of points. One application has been in the efficient transfer of data between maps on different projections. While the transfer of moderate amounts of data is satisfactorily accomplished using the analytical map projection formulas, polynomials are more efficient for massive transfers. Suitable coefficients for the polynomials may be determined more easily for general cases using least squares instead of Taylor series. A second area of research is in the determination of a map projection fitting an unlabeled map, so that accurate data transfer can take place. The computer can test one projection after another, and include iteration where required. A third area is in the use of least squares to fit a map projection with optimum parameters to the region being mapped, so that distortion is minimized. This can be accomplished for standard conformal, equalarea, or other types of projections. Even less distortion can result if complex transformations of conformal projections are utilized. This bulletin describes several recent applications of these principles, as well as historical usage and background.
Introduction The Little Piute Mountains in the eastern Mojave Desert expose a series of folds and thrust faults involving metamorphosed Paleozoic strata (Miller and others, 1982; Stone and others, 1983). Detailed mapping of these structures was undertaken to help elucidate regional Mesozoic structural evolution. Earlier geologic maps were prepared by Cooksley (1960a,b,c,d, generalized by Bishop, 1964) and Stone and others (1983). Deformed and metamorphosed Paleozoic and Triassic rocks form a stratal succession that was originally deposited in shallow seas on the North American craton. Based on lithologic sequence the units are correlated with unmetamorphosed equivalents 200 km to the northeast in the Grand Canyon, Arizona, and 35-50 km to the west in the Marble, Ship, and Providence Mountains, California (Stone and others, 1983). The Paleozoic sequence rests nonconformably on a heterogeneous basement of polydeformed Early Proterozoic gneiss (Miller and others, 1982; Wooden and Miller, 1990). Triassic and older rocks were deformed, metamorphosed to staurolite or andalusite grade, and intruded concordantly at their base by Late Cretaceous granodiorite (Miller and others, 1982).
Mapping surface water over time provides the spatially explicit information essential for hydroclimatic research focused on droughts and flooding. Hazard risk assessments and water management planning also rely on accurate, long-term measurements describing hydrologic fluctuations. Stream gages are a common measurement tool used to better understand flow and inundation dynamics, but gage networks are incomplete or non-existent in many parts of the world. In such instances, satellite imagery may provide the only data available to monitor surface water changes over time. Here, we describe an effort to extend the applicability of the USGS Dynamic Surface Water Extent (DSWE) model to non-US regions. We leverage the multi-decadal archive of the Landsat satellite in the Google Earth Engine (GEE) cloud-based computing platform to produce and analyze 372 monthly composite maps and 31 annual maps (January 1988–December 2018) in Cambodia, a flood-prone country in Southeast Asia that lacks a comprehensive stream gage network. DSWE relies on a series of spectral water indices and elevation data to classify water into four categories of water inundation. We compared model outputs to existing surface water maps and independently assessed DSWE accuracy at discrete dates across the time series. Despite considerable cloud obstruction and missing imagery across the monthly time series, the overall accuracy exceeded 85% for all annual tests. The DSWE model consistently mapped open water with high accuracy, and areas classified as “high confidence” water correlate well to other available maps at the country scale. Results in Cambodia suggest that extending DSWE globally using a cloud computing framework may benefit scientists, managers, and planners in a wide array of applications across the globe.
This is the twenty-eighth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions. This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, related changes in precipitation and streamflow, and chemical quality of water. Supplementary data, such as maps showing water-level contours, are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions. This report includes individual discussions of selected major areas of ground-water development in the State for the calendar year 1990. Water-level fluctuations and selected related data, however, are described from the spring of 1986 to the spring of 1991. Much of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Division of Water Rights, Utah Department of Natural Resources.
This is the twenty-ninth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions. This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, related changes in precipitation and streamflow, and chemical quality of water. Supplementary data, such as maps showing water-level contours, are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions. This report includes individual discussions of selected major areas of ground-water development in the State for the calendar year 1991. Water-level fluctuations and selected related data, however, are described from the spring of 1987 to the spring of 1992. Most of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Division of Water Rights and Division of Water Resources, Utah Department of Natural Resources.
This is the thirtieth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions. This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, related changes in precipitation and streamflow, and chemical quality of water. Supplementary data, such as maps showing water-level contours, are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions. This report includes individual discussions of selected major areas of ground-water development in the State for the calendar year 1992. Water-level fluctuations and selected related data, however, are described from the spring of 1988 to the spring of 1993. Much of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Divisions of Water Rights and Water Resources, Utah Department of Natural Resources.
This is the thirty-first in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions. This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, related changes in precipitation and streamflow, and chemical quality of water. Supplementary data, such as maps showing water-level contours, are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions. This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 1993. Water-level fluctuations and selected related data, however, are described from the spring of 1989 to the spring of 1994. Much of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Divisions of Water Rights and Water Resources, Utah Department of Natural Resources.
This is the thirty-second in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions. This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, related changes in precipitation and streamflow, and chemical quality of water. Supplementary data, such as maps showing water-level contours, are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions. This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 1994. Much of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Divisions of Water Rights and Water Resources.
This is the thirty-third in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions. This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, related changes in precipitation and streamflow, and chemical quality of water. Supplementary data, such as maps showing water-level contours, are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions. This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 1995. Most of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Divisions of Water Rights and Water Resources.
We are studying a sample of Maryland (2 %) and New Hampshire (4 %) Atlas blocks and a small sample in Maine. These three States used different sampling methods and block sizes. We compare sampling techniques, roadside with off-road coverage, our coverage with that of the volunteers, and different methods of quantifying Atlas results. The 7 1/2' (12-km) blocks used in the Maine Atlas are satisfactory for coarse mapping, but are too large to enable changes to be detected in the future. Most states are subdividing the standard 7 1/2' maps into six 5-km blocks. The random 1/6 sample of 5-km blocks used in New Hampshire, Vermont (published 1985), and many other states has the advantage of permitting detection of some changes in the future, but the disadvantage of leaving important habitats unsampled. The Maryland system of atlasing all 1,200 5-km blocks and covering one out of each six by quarterblocks (2 1/2-km) is far superior if enough observers can be found. A good compromise, not yet attempted, would be to Atlas a 1/6 random sample of 5-km blocks and also one other carefully selected (non-random) block on the same 7 1/2' map--the block that would include the best sample of habitats or elevations not in the random block. In our sample the second block raised the percentage of birds found from 86% of the birds recorded in the 7 1/2' quadrangle to 93%. It was helpful to list the expected species in each block and to revise this list annually. We estimate that 90-100 species could be found with intensive effort in most Maryland blocks; perhaps 95-105 in New Hampshire. It was also helpful to know which species were under-sampled so we could make a special effort to search for these. A total of 75 species per block (or 75% of the expected species in blocks with very restricted habitat diversity) is considered a practical and adequate goal in these States. When fewer than 60 species are found per block, a high proportion of the rarer species are missed, as well as some of the common ones. Similarity indices based on fewer than 60 species per block reflect coverage rather than habitat affinities. Atlas blocks that are ecologically similar should have similarity indices (S) of at least 0.80 to be considered adequately covered. S = 2C/(A + B), where C is the number of species in common and A and B are species totals for each of the two blocks being compared. A series of 15 13-minutes roadside stops yielded more species than 15 off-road stops, but off-road stops always had some species not detected at the roadside stops. A series of timed stops is an excellent way to map relative abundance if the stops are standardized with respect to time of day and weather, and the counts are made by observers of comparable ability. Efforts to estimate Atlas block populations in powers of 10 (as in the French Atlas) have not gained acceptance in U.S.A. Most observers feel unqualified to make estimates. An efficient way to Atlas a block is to make at least 3 early morning visits to 15 or more specific stops. Arrive in the block early enough to check for nocturnal species on at least two days; and after completing the specific stops, search the block for other species and for confirmations.
By selecting one of the four series options shown below, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively, the user will be taken to that map.
By selecting one of the four series options shown below, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively, the user will be taken to that map.
This report is the sixteenth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, prepared cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions. This report, like the others in the series, contains information on well construction, ground-water withdrawals, water-level changes, and related changes in precipitation and streamflow. Supplementary data such as graphs showing chemical quality of water and maps showing water-table configuration are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions. This report includes individual discussions of selected major areas of ground-water withdrawal in the State for the calendar year 1978. Water-level fluctuations, however, are described for the period spring 1978 to spring 1979. Much of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Division of Water Rights, Utah Department of Natural Resources.