First posted August 11, 2021 For additional information, contact: Office of Science Quality and IntegrityU.S. Geological Survey12201 Sunrise Valley DriveMS 911Reston, VA 20192Contact Pubs Warehouse As an unbiased, multidisciplinary science organization, the U.S. Survey (USGS) is dedicated to timely, relevant, impartial study health our ecosystems environment, natural resources, impacts climate ...

A vectorized polynomial preconditioned conjugate gradient (PPCG) numerical algorithm is presented as an additional solver package interfaced with the Modular Three-Dimensional Finite Diierence GroundWater Flow Model 1] (hereafter called the USGS model). The USGS model with its existing strongly implicit procedure (SIP) and slice-successive overrelaxation (SSOR) solution packages and with the ne...

First posted July 27, 2021 For additional information, contact: Water Resources Mission AreaU.S. Geological Survey12201 Sunrise Valley DriveReston, VA 20192Contact Pubs Warehouse The United States faces growing challenges to its water supply, infrastructure, and aquatic ecosystems because of population growth, climate change, floods, droughts. To help address these challenges, the U.S. Survey A...

The United States Geological Survey (USGS) in cooperation with The Ohio State University (OSU) and Calgary University (CU) have developed procedures and software for the efficient calibration of metric quality aerial cameras; both filmand CCD-based sensors. With the advent of the Global Positioning System (GPS), and its efficient use to position the exposure station of the aerial camera, it bec...

[1] An atmosphere/glacier modeling system is described for estimating the mass balances of glaciers in both current and future climate in order to estimate their probable future contributions to rising sea level. Dynamically downscaled output from a regional atmospheric model, driven by global atmospheric reanalysis, is used to force a precipitationtemperature-area-altitude (PTAA) glacier mass ...

We have implemented the USGS National Climate Change Viewer (NCCV), which is an easy-to-use web application that displays future projections from global climate models over the United States at the state, county and watershed scales. We incorporate the NASA NEX-DCP30 statistically downscaled temperature and precipitation for 30 global climate models being used in the Fifth Assessment Report (AR...

Calculations based on US Geological Survey (USGS) digital elevation models (DEMs) inherit any errors associated with that particular representation of topography. We investigated the potential impact of error in a USGS 30 m DEM on terrain analysis over 27 km. The difference in elevation between 2652 differential Global Positioning Systems measurements and USGS 30-m DEM derived elevations provid...

Terrain attributes are commonly used to explain the spatial variability of agronomic, pedologic, and hydrologic variables. The terrain attributes studied here (elevation, slope, aspect, and curvature) are estimated readily from digital elevation models (DEMs), but questions remain about how the accuracy and sample spacing of the elevation data affect the estimated attributes. The main objective...

This paper investigates the effect of land use and digital elevation models spatial resolution and scale on the simulation of stream flow in two coastal watersheds located in the Mississippi Gulf Coast (USA). Four elevation datasets were used: USGS DEM, NED, NASA’s SRTM and IFSAR (300, 30, 30, and 5 meter resolution, respectively). Three land use datasets were included in this study: USGS GIRAS...