Geography Matters

From Theodolites to GIS

GeographyMatters — Fri, 15 Aug 2008 16:50:00 GMT

Originally set up in 1767, the Survey of India is the government's oldest department and in charge of all of the its mapping and surveying efforts. Since coordinating the Great Trigonometric Survey, it has expanded over the years to 23 geospatial data centers and 18 divisions that range in responsibilities from tides to aerial survey. The agency uses GIS extensively in its mapping activities.

The Great Arc (ISBN 0-00-257062-9) by John Keay details the challenges in completing the Survey of India's Great Trigonometric Survey or Great Arc, an epic project that both carefully mapped the country and measured the curvature of the earth.

Begun in 1800 by William Lambton, an English army captain, and completed by his assistant George Everest, for whom the famous Himalayan Mountain was named, the project stretched for nearly 50 years and 1,600 miles.

The survey process was based on triangulation, a method in which a baseline is accurately measured and the angles of the desired triangle are calculated by sighting a point with a theodolite, an instrument used to measure both horizontal and vertical angles. One side of the calculated measurements of the first triangle is then used as the base line for the next triangle and so on. The end result was a triangulation network of varying sizes that progressively moved towards the Himalayas.

This procedure is complicated because the earth is uneven and shaped like an oblate spheroid. This means that the angles of the calculated triangles did not add up to 180 degrees and spherical excess had to be calculated and removed.

Lambton's Great Theodolite used by both William Lambton and George Everest during the Great Trigonometric Survey of India was capable of measuring both the vertical and horizontal access, it weighed approximately half a ton and needed twelve men to carry it. This image was taken from the 'Historical Records of the Survey of India 1830 to 1843', Volume IX plate 6.

10th Anniversary of GIS Day

GeographyMatters — Thu, 14 Aug 2008 20:54:00 GMT

This year we celebrate the tenth anniversary of GIS Day. Since its beginning in 1999, more than 10,000 organizations in more than 80 countries have participated in this worldwide event. Events have included everything from map drawing contests to treasure hunts, all with the same goal, to increase global awareness of GIS. Read more about the memorable past ten years of GIS Day. Visit http://www.gisday.com/ to learn how to start planning your own event. GIS Day 2008 is November 19.

GIS Day 2008 Promotional Flier

GeographyMatters — Fri, 25 Jul 2008 20:59:00 GMT

The new GIS Day 2008 flier is now available! GIS Day is fast approaching on November 19^th and the new flier provides both information and inspiration for celebrating your event. This colorful flier encourages educators, professionals, and students alike to participate in this global event. Download the flier to help you get the word out about GIS Day.

GIS Volunteers for Barack Obama

GeographyMatters — Fri, 11 Jul 2008 01:14:00 GMT

Students with GIS experience can put their skills to use as a volunteer for Barack Obama's presidential campaign.

GIS Intern, Barack Obama Campaign Office, Chicago (March 17, 2008)
The Barack Obama campaign is looking for a few good GIS interns in our Chicago office. Campaigns are spatially based and, while offering no pay, these positions present an opportunity to learn some creative applications of GIS and help out a great candidate. Good ArcGIS skills required, minimum 10 hours a week and it would be preferable if you had your own license/computer setup. The specific projects will range from straightforward map creation to complex analytical work with large datasets. If you're an Obama supporter and looking for a way to use your specialized skills to help out please contact Patrick DeTemple at pdetemple@barackobama.com.

GIS Day Anniversary Display

GeographyMatters — Wed, 09 Jul 2008 21:07:00 GMT

This year marks the tenth anniversary of GIS Day. To commemorate this milestone, there will be a special display at the 2008 ESRI International User Conference. The multi-panel display will include photos of GIS Day events worldwide, the history of GIS Day, and a few featured events from the last ten years.

Governor of California Acknowledges Benefits of GIS in Major Address

GeographyMatters — Tue, 01 Jul 2008 18:40:00 GMT

"Well, we are now, because of her (State Chief Information Officer Teri Takai) help, we are moving full steam ahead. A perfect example is, for instance, GIS. GIS is a form of digital mapping technology, kind of like Google Earth but better. (Laughter) During last year's firestorm it allowed firefighters to see through the smoke, giving them a more accurate real-time view of the conditions on the ground. And because of that, many of them told me that saved lives and it saved an endless amount of homes. And this is just the start, because I have directed Teri to create a taskforce now to help other agencies and departments to tap into that vast potential of GIS."

- From Governor Arnold Schwarzenegger's keynote address at the Conference on California's Future on May 15, 2008

New GIS Day Poster

GeographyMatters — Mon, 23 Jun 2008 17:08:00 GMT

The new GIS Day poster is an ideal educational tool for K-12 students. The front side is a colorful poster containing GIS Day photos from over the years. The inside provides a brief overview of GIS and encourages readers to explore GIS by hosting a GIS Day event, thinking about a future in GIS, or visiting a collection of interactive GIS-related Web sites. Download the Poster for your GIS Day event.

Global Warming and the Shrinking Gangotri Glacier

GeographyMatters — Fri, 13 Jun 2008 21:11:00 GMT

Situated in the Himalayas at around 10,500 feet, the Gangotri Glacier is the source of the holy River Ganges. Its headwaters pour from an ice cave on the glacier and flow for more than 1,500 miles to the Bay of Bengal.

Among more than 7,000 Himalayan glaciers, Gangotri is one of the largest, measuring approximately 18 miles long and 1-3.5 miles wide.

As massive as this might seem, a recent United Nations climate report indicates that the Himalayan glaciers, the source of Asia's biggest rivers, are melting more quickly each year and could disappear within only a few decades. Rivers in the region, including the Ganges may become seasonal rivers, which has serious ramifications for poverty and the economies in the region, warns the report issued by the UN Environment Programme (UNEP).

The River Ganges is considered sacred in Hinduism and is said to flow through the hair of Shiva, a principal deity in that religion. Hindus believe that bathing in the river causes the remission of sins and facilitates the attainment of salvation. They often travel from distant places to distribute the ashes of their kin in its waters. In addition, the Ganges provides water for drinking and farming for more than 500 million people.

Tracing the retreat of the Gangotri Glacier (1780-2001) - Image courtesy of Wikipedia

GIS - A Critical Tool in Fighting the Spread of Infectious Disease

GeographyMatters — Mon, 02 Jun 2008 20:23:00 GMT

GIS is a vital tool for scientists and public health officials investigating the cause and spread of deadly diseases around the world. Outbreaks of infectious diseases such as SARS can be quickly analyzed using GIS tools.

The SARS Mapping Web site was developed by ESRI China (Hong Kong) to track the locations of reported SARS cases. It is part of an ongoing program to serve the local community through the innovative deployment of GIS. The site was established and hosted as a voluntary initiative. Once the epidemic was over, the site was taken offline. While it is hoped there will be no call to reactivate it, the site is ready if the need arises.

Courtesy of the ESRI.com Web site http://www.esri.com/news/arcnews/summer04articles/tracking-sars.html

John Snow and the Origins of Disease Mapping

GeographyMatters — Wed, 21 May 2008 19:49:00 GMT

During the 1800's, England suffered regular epidemics of Asiatic cholera that killed thousands of its residents. Opinions in the medical community regarding the origins of the disease were divided, and, as such, no effective prevention or treatment was implemented.

Physician John Snow set out to prove his theory that cholera was a disease spread by unsanitary water. During the 1854 outbreak, he began an epidemiological study of the area and residents around the public water pump on Broad Street in London. Snow tracked hundreds of cases of cholera to nearby schools, restaurants, businesses and pubs. By mapping the residences of those who died from the outbreak in proximity to the Broad Street pump and representing the fatalities as short lines at those addresses, Snow developed positive proof that the pump was the source of the cholera epidemic.

For additional information, see "John Snow - a historical giant in epidemiology" on the UCLA Department of Epidemiology Web site http://www.ph.ucla.edu/epi/snow.html. The included map is courtesy of that site.

Essential Information Organization Uses GIS to Monitor Bank Lending Trends

GeographyMatters — Wed, 07 May 2008 23:11:00 GMT

Founded in 1982 by Ralph Nader, Essential Information is a non-profit, tax-exempt organization involved in a variety of projects to encourage citizens to become active and engaged in their communities.

The organization's GIS Action for Economic and Social Justice Project addresses a range of crucial and closely interwoven social and economic justice needs. The project focuses primarily on core social and economic concerns: workers earning less than a livable wage, affordable housing needs, regressive federal budget policies, housing discrimination and exclusionary housing policies, and access to financial services, especially for community reinvestment purposes, small business, and small farms.

Subprime lending, which has grabbed newspaper headlines for the past several months, has been a long time concern for the organization. Below is a map of Richmond, Virginia depicting the subprime lenders' market share of conventional refinancing loans in 2002 as viewed by census tract. The diagonal overlay highlights minority residential areas.

Courtesy of the Essential Information Web site http://www.public-gis.org/index.html

Mapquotes - Eleanor Roosevelt

GeographyMatters — Wed, 07 May 2008 23:07:00 GMT

"Where, after all, do universal human rights begin? In small places, close to home-so close and so small that they cannot be seen on any map of the world. Yet they are the world of the individual person: The neighborhood he lives in; the school or college he attends; the factory, farm or office where he works. Such are the places where every man, woman and child seeks equal justice, equal opportunity, equal dignity without discrimination. Unless these rights have meaning there, they have little meaning anywhere. Without concerted citizen action to uphold them close to home, we shall look in vain for progress in the larger world."

From Statements at Presentation of In Your Hands: A Guide for Community Action for the Tenth Anniversary of the Universal Declaration of Human Rights (1958)

Logo courtesy of the United Nations Human Rights Web site http://www.ohchr.org/EN/Pages/WelcomePage.aspx

The 60^th anniversary of the Universal Declaration of Human Rights will be celebrated on December 10, 2008.

Who Inspired GIS Day?

GIS-Day-Team — Tue, 06 May 2008 19:09:00 GMT

Do you know where the inspiration for GIS Day came from? During a GIS Day kickoff celebration at the National Geographic Society in 1999, Jack Dangermond, ESRI president, said GIS Day was inspired by Ralph Nader, consumer advocate and environmentalist, as a way to inform the public about the emerging role and benefit of GIS. Read more.

Mark your calendar; the tenth annual GIS Day celebration will be held on Wednesday, November 19, 2008. Learn more about GIS Day.

ESRI Supports Conservation Efforts Throughout the World

GeographyMatters — Wed, 23 Apr 2008 22:01:00 GMT

ESRI has participated for many years in a number of conservation initiatives including those projects sponsored by the UNEP-WCMC and the highly successful Conservation Geoportal.

The Conservation Geoportal is a collaborative effort by and for the conservation community to facilitate the discovery and publishing of GIS data and maps, to support conservation decisionmaking and education. It is primarily a data catalog, intended to provide a comprehensive listing of GIS datasets and map services relevant to biodiversity conservation. The Conservation Geoportal does not actually store maps and data, but rather the descriptions and links to those resources, known as metadata.

The Conservation Geoportal is designed to make it quick and easy for conservation practitioners to find, and if possible, preview and download GIS data and maps. Similarly, it is easy for conservation data publishers to post metadata describing the data and maps they want to share, how to access them, and under what terms. This is a free tool for all conservation practitioners and supporters to use and contribute content.

Image courtesy of the Conservation GeoPortal http://www.conservationmaps.org/index.jsp

Happy Earth Day 2008!

GIS-Day-Team — Tue, 22 Apr 2008 16:38:00 GMT

As a follow-up to our first post titled "Celebrate Earth Day with GIS," check out the interesting things you can do with ArcGIS Explorer for Earth Day.