Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Processes”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,153 records · Page 64Linked to original sources
USGS2001

Spatial variability of sediment erosion processes using GIS analysis within watersheds in a historically mined region, Patagonia Mountains, Arizona

In this study, a geographic information system (GIS) is used to integrate and accurately map field studies, information from remotely sensed data, watershed models, and the dispersion of potentially toxic mine waste and tailings. The purpose of this study is to identify erosion rates and net sediment delivery of soil and mine waste/tailings to the drainage channel within several watershed regions to determine source areas of sediment delivery as a method of quantifying geo-environmental analysis of transport mechanisms in abandoned mine lands in arid climate conditions. Users of this study are the researchers interested in exploration of approaches to depicting historical activity in an area which has no baseline data records for environmental analysis of heavily mined terrain.

Arizona↗
USGS2000

Processed Thematic Mapper Satellite Imagery for Selected Areas within the U.S.-Mexico Borderlands

The study is summarized in the Adobe Acrobat Portable Document Format (PDF) file OF00-309.PDF. This publication also contain satellite full-scene images of selected areas along the U.S.-Mexico border. These images are presented as high-resolution images in jpeg format (IMAGES). The folder LOCATIONS in contains TIFF images showing exact positions of easily-identified reference locations for each of the Landsat TM scenes located at least partly within the U.S. A reference location table (BDRLOCS.DOC in MS Word format) lists the latitude and longitude of each reference location with a nominal precision of 0.001 minute of arc

Open-File Report↗
USGS2000

MODFLOW-2000, The U.S. Geological Survey modular ground-water model: User guide to modularization concepts and the ground-water flow process

MODFLOW is a computer program that numerically solves the three-dimensional ground-water flow equation for a porous medium by using a finite-difference method. Although MODFLOW was designed to be easily enhanced, the design was oriented toward additions to the ground-water flow equation. Frequently there is a need to solve additional equations; for example, transport equations and equations for estimating parameter values that produce the closest match between model-calculated heads and flows and measured values. This report documents a new version of MODFLOW, called MODFLOW-2000, which is designed to accommodate the solution of equations in addition to the ground-water flow equation. This report is a user's manual. It contains an overview of the old and added design concepts, documents one new package, and contains input instructions for using the model to solve the ground-water flow equation.

Open-File Report↗
USGS2003

Processing large remote sensing image data sets on Beowulf clusters

High-performance computing is often concerned with the speed at which floating- point calculations can be performed. The architectures of many parallel computers and/or their network topologies are based on these investigations. Often, benchmarks resulting from these investigations are compiled with little regard to how a large dataset would move about in these systems. This part of the Beowulf study addresses that concern by looking at specific applications software and system-level modifications. Applications include an implementation of a smoothing filter for time-series data, a parallel implementation of the decision tree algorithm used in the Landcover Characterization project, a parallel Kriging algorithm used to fit point data collected in the field on invasive species to a regular grid, and modifications to the Beowulf project's resampling algorithm to handle larger, higher resolution datasets at a national scale. Systems-level investigations include a feasibility study on Flat Neighborhood Networks and modifications of that concept with Parallel File Systems.

Open-File Report↗
USGS2004

Monitoring Colonias Development along the United States-Mexico Border: A Process Application using GIS and Remote Sensing in Douglas, Arizona, and Agua Prieta, Sonora

The U.S. Department of Housing and Urban Development (HUD) and the U.S. Geological Survey (USGS) have developed a joint project to create Internet-enabled geographic information systems (GIS) that will help cities along the United States-Mexico border deal with issues related to colonias. HUD defines colonias as rural neighborhoods in the United States-Mexico border region that lack adequate infrastructure or housing and other basic services. They typically have high poverty rates that make it difficult for residents to pay for roads, sanitary water and sewer systems, decent housing, street lighting, and other services through assessment. Many Federal agencies recognize colonias designations and provide funding assistance. It is the intention of this project to empower Arizona-Sonora borderland neighborhoods and community members by recognizing them as colonias. This recognition will result in eligibility for available economic subsidies and accessibility to geospatial tools and information for urban planning. The steps to achieve this goal include delineation of colonia-like neighborhoods, identification of their urbanization over time, development of geospatial databases describing their infrastructure, and establishment of a framework for distributing Web-based GIS decision support systems. A combination of imagery and infrastructure information was used to help delineate colonia boundaries. A land-use change analysis, focused on urbanization in the cities over a 30-year timeframe, was implemented. The results of this project are being served over the Internet, providing data to the public as well as to participating agencies. One of the initial study areas for this project was the City of Douglas, Ariz., and its Mexican sister-city Agua Prieta, Sonora, which are described herein. Because of its location on the border, this twin-cities area is especially well suited to international manufacturing and commerce, which has, in turn, led to an uncontrolled spread of colonias. The USGS worked with local organizations in developing the Web-based GIS database. Community involvement ensured that the database and map server would meet the current and long-term needs of the communities and end users. Partners include Federal agencies, State agencies, county officials, town representatives, universities, and youth organizations, as well as interested local advocacy groups and individuals. A significant component of this project was development of relationships and partnerships in the border towns for facilitating binational approaches to land management.

Open-File Report↗