GIS Tech News #510 May, 2005 By: Arnie Williams
Agencies tap geospatial technologies for a variety of new and important uses in mining and earth sciences
In the next few editions of GIS Tech Trends, I'll offer a look at how a variety of disciplines are tapping GIS technology to accomplish important tasks. This month, I'll look at tools from GIS developer ESRI and the discipline of mining and earth science.
GIS users from the Los Alamos National Laboratory Earth and Environmental Division in New Mexico have used ESRI's ArcMap 8.3, along with Microsoft Excel and Windows 2000, to develop maps depicting space and time. Their project looked at groundwater analyte in West Central Los Alamos and Pueblo canyons from 1952 to 2002, displaying chemical concentrations of analyte and other chemicals based on data collected over that 50-year period.
Employing rose diagrams — often used to depict wind direction in geologic applications — the authors were able to sample location data with attributes of concentration and time, move the data into computer code and then depict the data in clock-diagram graphics according to geographic location (figure 1). Use of clock diagrams is not new, but using multiple clock diagrams as GIS symbology to emphasize movement of sampled data over time is a new concept that has been effective in identifying spatial and temporal trends when analyzing groundwater data.
Figure 1. A clock-diagram graphic created using ESRI ArcMap 8.3, illutrating detected groundwater analyte from 1952 to 2002 in Los Alamos and Pueblo canyons.
The same division of the Los Alamos National Laboratory utilized ArcGIS Spatial Analyst along with ArcMap 8.3 in a study of the Pajarito Plateau of Northern New Mexico. The study looked at stream flow losses and gains along canyon bottoms and other geological areas and correlated that data with filtration rates in higher elevations having conifer and aspen vegetation. These studies help anticipate effects of fire periods in the plateau and contribute to a growing database of surface studies for future analysis.
U.S. Geological Survey Studies
The U.S. Geological Survey has conducted a number of studies employing ESRI GIS technology. The National Wetlands Research Center used ArcView Image Analysis to study the effects of marshland loss in coastal Louisiana -- an area which loses some 34 square miles of marshland per year. Without action to reverse the trend, Louisiana could lose an area of marshland as large as the Washington, D.C.-Baltimore metropolitan area over the next 50 years. The study has looked at marshland loss from 1932 projecting out to 2050 as a first step in arriving at solutions to the problem.
Another division of U.S. Geological Survey has taken a longer view of surface land areas using ArcInfo, ArcView, Adobe Illustrator, LT4X computer programming and Avenza MAPublisher to create maps that show aerial distributions of surface geologic deposits that have accumulated over the past 2 million years in the Eastern and Central United States. These maps were based on data collected from some 31 published maps having different projections and bases that were recompiled to match a common digital base.
Surface studies and below-the-surface data are crucial in earthquake zones, such as the Santa Rosa Quadrangle in California. The U.S. Geological Survey has used ArcInfo software to study and map significant seismic activity from 1969 to 1995. The earthquake clusters map identifies the most significant temporal clusters and looks at time-dependent properties. The maps also show the time-dependent relation between geothermal power production in the area and seismic activity.
GIS use for surface geology is not limited to the United States. In Jamaica, the Alpart Mining Venture has used ArcGIS 8.3, ArcGIS Spatial Analyst, ArcInfo, ArcSDE, ArcView and ArcGIS Geostatistical Analyst for bauxite mining applications. Jamaica is the world's fourth-largest producer of bauxite, the primary mineral used to produce alumina. It is also the second-largest source of revenue for the country.
Mining efforts in the area are constrained by rugged terrain, population density, varying ore quality and small deposit sizes. Drawing upon satellite imagery and orthorectified aerial photography, data is implemented to manage, analyze and display location, tonnage and quality of ore deposits. Using ArcGIS and Vulcan 3D modeling and mine planning software, various scenarios can be simulated to ensure more efficient mining practices.
The Czech Geological Survey is utilizing ArcGIS 3D Analyst and ArcSDE to convert geological archived maps into digital form. The process ran from 1994 to 1998, and the GIS system now holds more than 260,000 geological objects from the entire Czech Republic. At the heart of the project is the unified national geological index, which consists of four main types of information: chronostratigraphical units, regional units, lithostratigraphical units and lithological description of rocks.
GIS will obviously continue to play an important role in earth science around the world. In the coming months, we'll look at other disciplines and applications from other developers, such as Intergraph and Autodesk.
ESRI GIS and Mapping Software http://www.esri.com
Upcoming GIS Events
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Twenty-Fifth Annual ESRI International User Conference
July 25?29, 2005
San Diego Convention Center, San Diego, California
A forum for sharing ideas, expertise and practical applications of GIS. http://www.esri.com/events/uc/index.html
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September 21-23, 2005
INVESCO Field at Mile High, Denver, Colorado
Conference will include technical sessions and workshops, job fair, exhibition, technical tours and a geocaching event. http://GISintheRockies.org
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November 14-16, 2005
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