GIS MAPPING

One challenge in the environmental industry is communicating data to diverse groups with varying technical know-how and inconsistent educational backgrounds. VET finds that outstanding maps are the most effective tool for communicating information to a wide range of individuals. A map provides spatial context for the subject matter being conveyed in a clean and concise manner. A map is a communication device and tool that, based on the information displayed, compels the audience to take specific mental and/or physical action. A map provides a reference of distance and direction between physical elements from rivers, streams, and sediments to buildings and property boundaries.

Click here for an article from the National Center for Biotechnology Information on the first ever instance of how a map was the main tool in solving one of the large-scale epidemics of cholera.

• Area Map: this Exhibit defines the surrounding area of a Site including roads, streams, rivers, wells, bodies of water, and pinpoints schools, hospitals, and emergency response services. This Exhibit gives context of the county where the Site is located and the enlarged vicinity of the Site.

• Parcel Map: this Exhibit defines the boundaries of the Site, noting water resources (National Hydrology Dataset), wetlands (National Wetland Inventory), flood zones (Federal Emergency Management Agency (FEMA)), and roadways. Determining water impacted areas helps in defining potential obstacles to on-Site development.

• Soils Map: this Exhibit defines the list of soil types found on the Site. The hydric soils within this list are noted for drainage quality purposes to assess the likelihood of wetlands developing on-Site. This allows for further understanding of the infiltration, permeability, and other qualities of the soils that may affect development on the property.

• Site Map with Adjoining Properties: this Exhibit outlines VET’s observations taken during the Site visit, noting the ownership of the Site itself and of the surrounding parcels. Observations consist of points of interest that may have significant environmental impacts or act as obstacles to development. These observations may include, but are not limited to, potential karst features, hydrophytic vegetation, stressed vegetation, and signs of contamination.

• Sample Location Maps: this Exhibit provides a visual reference of the exact location of sampling events performed on-Site, defining the concentrations of contaminants. This map develops understanding of data trends and allows for further action such as establishing a potential remediation area.

VET utilizes GIS software to produce industry-leading map exhibits by capturing, integrating, and analyzing detailed comprehensive data in an easy to interpret format. This is done by conducting in-depth desktop reconnaissance with data obtained from publicly available resources and from VET’s field operations.

The main projects VET utilizes GIS for include:

• Phase I Environmental Site Assessments (ESAs)

• Phase II Investigations

• Storm Water Pollution Prevention Plans (SWPPPs)

• Spill Prevention Control & Countermeasure (SPCC) Plans

• Jurisdictional Waters Determination (Stream and Wetland Delineations)

• Further Site Investigations (FSIs)

• Sinkhole Evaluations

• Planning & Zoning Permitting

• Lead Testing & Survey

They say, “a picture paints a thousand words.” As technical writers, we can absolutely attest to the importance of detailed, descriptive, and compelling technical reports. But there is no question that an excellent report coupled with an informative and aesthetically pleasing map paints the picture better!

GIS is utilized to display spatial data to visually convey information to a specific audience. The message presented by this information may identify a potential issue, show a trend in statistics, and/or lay forth a spatial relationship. Spatial relationships may consist of land-use patterns, such as the association between an agricultural and commercial area, or location of topographic elements, such as wetlands and streams.

Click here for further information provided by ESRI on how GIS is applied to the real world.

The digital formatting of GIS and the associated data eliminates the need for information to pass through as many hands. This expedites the project flow, cutting time and cost for the producer and consumer during map production. Similarly, this digital formatting allows for ease of reproduction and distribution of the final products between both the collaborators and with the target audience.

GIS data is versatile and may be saved and downloaded without difficulty. Making this data readily accessible, allows for the information to be applied to other related projects to convey alternate spatial relationships. GIS mapping aids in informing clients and in the planning and predicting efforts for the future of a site.

Click here for information published by the National Academies Press on a study of flood mapping and why mapping of specific hazards becomes important in protecting lives and property.

GIS mapping provides a tool that:

• Creates a clear visual representation of information pertinent to the client;

• Provides the client a straightforward tool to aid decision making;

• Clean and clear graphics improve communications between the client and consultant;

• Refines recordkeeping of on-site observations;

• Offers geographic context to pertinent on-Site environmental conditions; and,

• Aids in preventative measures by warning individuals of potential hazards or protected areas on-Site.

When paired with a written report, the information conveyed is enhanced. This enhancement brings about a higher level of understanding of the subject matter through further interpretation and the highlighting of pertinent spatial relationships between physical elements.

Click here to learn more from the National Academies Press about how GIS aids in decision making.

The five main components that characterize GIS are: software, hardware, data, people, and methods.

• GIS requires specific software to run. Tools within the software allow for the manipulation of data, a geodatabase to store data, and an interface to access the data visually.

• GIS software is run on a computer, which consists of hardware components. GIS software may be run on a singular computing device (desktop, laptop, handheld) or network of a combination of compatible computing devices.

• Data is the main focus of all GIS operations. This encompasses the information collected, manipulated, and conveyed to an audience through GIS tools and processes.

• People create the bridge between the GIS processes and the final visual product. GIS Analysts manage and apply GIS data solutions to real-world issues to paint the desired picture for the end user(s).

• Methods allow the production of GIS maps by integrating data, people, software, and hardware into operating procedures and processes to generate a compelling end product.

ESRI provides an example of these five components in conjunction in their article on a case study of managing assets and land use.

GIS data consists of a combination of vector and raster elements.

Vector models consist of paths. Paths are points and lines that are tied to specific locations on the Earth’s surface. Within GIS software, vector models may include lines drawn for roadways or streams, polygons outlining bodies of water, topographic lines, or points on a map where libraries are within a city, for example.

Raster models consist of many pixels. A pixel is a small cell illuminating a specific color or series of colors. This series of pixel cells makes up an image, which displays specific locations on the Earth’s surface. Raster data is most commonly associated with satellite imagery. Each pixel within the image is assigned a location on the globe, allowing for the raster model’s location to be overlaid accurately. This process of assigning pixels to an exact location is called georeferencing.

Raster models overlaid with vector models provide a full visual scope to a project. Using both models allows for clear pinpointing of areas of interest on an easily identifiable aerial, a photograph, for example. During a development project, it is pertinent to know the location of sinkholes, wetland areas, and property boundaries to determine cost and scope of operation and to effectively identify and locate protected resources.

For further information from ESRI on raster data and how it is used, click here.