GIS in Environmental Management

Since the early 1970s, geographic information systems (GIS) have been used extensively in environmental management using spatially intensive and extensive databases in an integrated manner. The geographic database includes the collection of samples that are truly representative of any large irregular regions. These samples are turned into useful information to monitor environment that might otherwise be invisible. GIS works on the principle that by bringing together geographic data from different sources and using them in an integrated manner, proper communication among the public and policymakers becomes possible, enabling them to engage in complex environmental decision making. Simply put, GIS bridges the gap between the hard and soft sciences in environmental decision making. It plays a vital role in data validation, digital data transfer standards, and data retrieval, dissemination, and analysis. The evolution of spatial data standards, the

Internet, and the next generation of GIS technology will allow all types of users to access environmental information in its proper spatial context in a cost-effective manner. GIS can help deal with location issues and understanding why and how certain things happen at certain locations and how to allocate demand for services.

Though GIS use in environmental management started with the visualization of different layers in the late 1970s, today, it ranges from land surface analysis to emergency services such as forest fire prevention, to hazard mitigation and planning, monitoring air pollution and control, disaster management, precision farming and animal litter applications, human health issues, planning and managing natural resources, and assessing the environmental consequences of economic development. These applications of GIS involve hypothesis testing and geovisualization.

Other applications of GIS in environmental management that are related to land surface and subsurface include terrain modeling, mine exploration, land reclamation, and mapping areas of rehabilitation. Through the overlay of various thematic layers representing spatial distributions of environmental variables and the mathematical modeling changes in these variables, GIS helps in calculating and visualizing the spatial relationships of biophysical factors directly influencing the environment. Factors such as steepness of slopes, aspects, and vegetation density can be viewed and overlaid together to determine various environmental parameters and to conduct impact analyses. The integrated information system used in GIS leads to better decision making within the geographic framework through an understanding of how elements of the environment interact across a landscape. This understanding helps not only to display relationships among key variables but also to test hypotheses concerning, for example, the status of habitats, wetlands, water quality, channel characteristics, adjacent land uses, and natural features in an environment.

GIS applications touch all our daily activities; GIS links environment regulations with human day-to-day activities. Its use to monitor humanenvironment interactions results in the production of more effective, efficient, equitable, and predictable outcomes. For example, GIS is used in [Page 1299]the analysis of discharge contents of streams and rivers, hazardous substance tracking, landfill sites, waste transfer treatments, disposal sites, and enforcement and prohibition notices brought against organizations as per environment regulations.

In monitoring air and water pollution and in pollution control, disaster management GIS tools can be used in profiling pollution levels using pollution gradient maps. They are used to locate devastation sites and to estimate the amount of devastation. By using GIS, an analyst can rapidly map waste storage sites; describe the volume, content, and state of waste containers; retrieve previous inspection records to compare them with existing environmental conditions; and view environmental data in relation to adjacent geographic features such as waterways, neighborhoods, or other sensitive areas (e.g., high-risk zones for landslides) and in relation to local water pollution levels.

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