GIS SURVEYING

GIS SURVEYING

           A GIS is a tool for making and using spatial information. Among the many definitions of GIS, we choose:

A GIS is a computer-based system to aid in the collection, maintenance, storage, analysis, output, and distribution of spatial data and information. When used wisely, GIS can help us live healthier, wealthier, and safer lives.

          GIS and spatial analyses are concerned with the quantitative location of important features, as well as properties and attributes of those features.

         Mount Everest is in Asia, Timbuktu is in Mali, and the cruise ship Titanic is at the bottom of the Atlantic Ocean. A GIS quantifies these locations by recording their coordinates, numbers that describe the position of these features on Earth.

         The GIS may also be used to record the height of Mount Everest, the population of Pierre, or the depth of the Titanic, as well as any other defining characteristics of each spatial feature.

         Each GIS user may decide what features are important, and what attributes are worth recording. For example, forests are important to us. They protect our water supplies, yield wood, harbor wildlife, and provide space to recreate.  

         We are concerned about the level of harvest, the adjacent land use, pollution from nearby industries, or when and where forests burn.

          Informed management requires at a minimum knowledge of all these related factors, and, perhaps above all, the spatial arrangement of these factors. Buffer strips near rivers may protect water supplies, clearings may prevent the spread of fire, and polluters downwind may not harm our forests while polluters upwind might.

           A GIS helps us analyze these spatial relationships and interactions. A GIS is also particularly useful at displaying spatial data and reporting the results of spatial analysis. In many instances GIS is the only way to solve spatially-related problems.

GIS Tool

          GIS are essential tools in business, government, education, and nonprofit organizations, and GIS use has become mandatory in many settings.

          GIS have been used to fight crime, protect endangered species, reduce pollute epidemics, and improve public health; in short, GIS have been instrumental in addressing some of our most pressing societal problems.

         GIS tools in aggregate save billions of dollars annually in the delivery of governmental and commercial goods and services. GIS regularly help in the day-to-day management of many natural and man-made resources, including sewer, water, power, and transportation networks.

         GIS are at the heart of one of the most important processes in U.S. democracy, the constitutionally mandated reshaping of U.S. congressional districts, and hence the distribution of tax dollars and other government resources.

                                               Why Do We Need GIS?

         GIS are needed in part because human populations and consumption have reached levels such that many resources, including air and land, are placing substantial limits on human action Human populations have doubled in the last 50 years, surpassing 6 billion, and we will likely add another 4 billion humans in the next 50year.

 The first 100,000 years of human existence caused scant impacts on the world’s resources, but in the past 300 years humans have permanently altered most of the earth’s surface.

GIS allow us to analyze the relative spatial location of important geographic features. The satellite image at the center shows a forested area in western Oregon, United States, with a patchwork of lakes (dark area, upper left and middle right), forest and clearings (middle), and mountains and desert (right). Spatial analyses in a GIS may aid in ensuring sustainable recreation, timber harvest, environmental protection, and other benefits from this and other globally important regions (courtesy NASA).

          The first 100,000 years of human existence caused scant impacts on the world’s resources, but in the past 300 years humans have permanently altered most of the earth’s surface.

          The atmosphere and oceans exhibit a decreasing ability to benignly absorb carbon dioxide and nitrogen, two primary waste products of humanity. 

         Silt chokes many rivers and there are abundant examples of smoke, ozone, or other noxious pollutants substantially harming public health  By the end of the 20th century most lands south of the boreal region had been farmed, grazed, cut, built over, drained, flooded, or otherwise altered by humans.

         GIS help us identify and address environmental problems by providing crucial information on where problems occur and who are affected by them.

        GIS help us identify the source, location, and extent of adverse environmental impacts, and may help us devise practical plans for monitoring, managing, and mitigating environmental damage.

          Human impacts on the environment have spurred a strong societal push for the adoption of GIS. Conflicts in resource use, concerns about pollution, and precautions to protect public health have led to legislative mandates that explicitly or implicitly require the consideration of geography.

         The U.S. Endangered Species Act of 1973 (ESA) is an example of the importance of geography in resource management. The ESA requires adequate protection of rare and threatened organisms. Effective protection entails mapping the available habitat and analyzing species range and migration patterns.

        The location of viable remnant plant and animal populations relative to current and future human land uses must be analyzed, and action taken to ensure species survival. GIS have proven to be useful tools in all of these tasks.

        GIS use is mandated in other endeavors, including emergency services, flood protection, disaster assessment and management and infrastructure development.

Public organizations have adopted GIS because of legislative mandates, and because GIS aid in governmental functions. For example, emergency service vehicles are regularly dispatched and routed using GIS.

Human population growth during the past 400 years has increased the need for

efficient resource use (courtesy United Nations and Ikonos).

 

The Sarychev volcano, in the Kuril Islands of Russia, erupted in June, 2009. Advanced satellite imaging allows us to track the eruptions and plumes, new space-based surveying aids in planning evacuation and mapping damage and repeated observation allows us to overlay observations, measure impacts, and plan for recovery (courtesy NASA).