What is GIS?

Our goals:

• Promote awareness of the benefits of GIS in Shasta County.
• Incorporate GIS into other information technology strategies.
• Provide accurate, high-quality, and up-to-date maps and data.
• Support and oversee the acquisition, standardization, and management of GIS data.
• Improve productivity.
• Eliminate the duplication of efforts.
• Educate employees and the public in the use of GIS applications, datasets, terminology and available resources.

What is a GIS?

A Geographic Information System, or GIS, is an intelligent mapping system. GIS is an organized collection of computer hardware, software, geographic data, and personnel designed to efficiently capture, store, update, manipulate, analyze, and display all forms of geographically referenced information. Or, in simple terms: A computer system capable of holding and using data describing places on the earth’s surface.

Many computer programs, such as spreadsheets, statistics packages or drafting packages can handle simple geographic or spatial data, but this does not necessarily make them a GIS. A true GIS links spatial data with geographic information about a particular feature on the map. For example, the centerline that represents a road on a map doesn’t tell you much about the road except its location. To find out the road’s width or pavement type, you must query the database. Using the information stored in the database, you could create a display symbolizing the roads according to the type of information that needs to be shown.

In short, a GIS doesn’t hold maps or pictures - it holds a database. The database concept is central to a GIS and is the main difference between a GIS and drafting or computer mapping systems, which can only produce a good graphic output. All contemporary geographic information systems incorporate a database management system.

A GIS gives you the ability to associate information with a feature on a map and to create new relationships that can determine the suitability of various sites for development, evaluate environmental impact, identify the best location for a new facility, and so on.

Essential Components of a Successful GIS

A sustainable GIS relies on the integration and optimization of different components:

1. People. Skilled GIS professionals are responsible for designing, maintaining, and deriving the maximum value from the GIS. In addition to GIS professionals, there are different levels of GIS users ranging from map viewers; data editors; map creators; programmers; and multidisciplinary experts.
2. Hardware. Several computing resources support the processing, storage, and dissemination of geographic data. Servers, mobile devices, GPS receivers, cameras, drones, and 3D scanners are a few of the peripherals used in GIS. If your staff will be using GIS software for spatial analysis or data edits, we strongly recommend you acquire a computer that has a multi-core processor with a clock speed of at least 2 GHz; 32 GB memory, at least 500 GB of disc space, a dedicated graphics card, Windows 11 operating system, Microsoft Edge or Chrome browsers, and at least two 30 inch monitors.
3. Software. Our team strives to keep the County on the most current versions of ArcGIS Pro and ArcGIS Enterprise. You do not need to install software to view common web map applications, they are accessible via a web browser.  
4. Data. Comprehensive spatial and attribute data is the foundation of a GIS. County departments author and maintain data that supports, or is derived from, their operations; they are responsible for ensuring completeness and currency. For example, Public Works ensures road data has the correct geometry, road name, and speed limit. Ancillary data to support GIS workflows includes satellite or aerial imagery, tabular files like spreadsheets, predictive models, and GPS data. The Open Data Portal hosts a library of data available for public consumption. Employees have access to a vast, secure geodatabase containing official County data that can aid decision-making.
5. Methods. It is imperative to establish rules for organizing, updating, and disseminating data or maps. Furthermore, implementing a geospatial strategy ensures GIS is aligned with our broader IT objectives and enterprise systems.

Questions a GIS can answer

Perhaps the simplest way to define a GIS is by listing the types of questions it can answer. For any application there are five generic questions that a sophisticated GIS can answer.

1. Location: What is at a given location? The first of these questions seeks to find out what exists at a particular location. A location can be described as a place name, zip code or address.
2. Condition: Where does something occur? Using spatial analysis the second question seeks to find a location where certain conditions are satisfied (e.g., an un-forested section of land at least 2,000 square meters in size, within 100 meters of a road, and with soils suitable for supporting buildings).
3. Trends: What has changed since...? The third question might involve a combination of the first two and seeks to find the differences within an area over time.
4. Patterns: What spatial patterns exist? You might ask this question to determine whether cancer is a major cause of death among residents near a nuclear power station. Just as important, you might want to know how many anomalies there are that don’t fit the pattern and where they are located.
5. Modeling: What if...? "What if ..." questions are posed to determine what happens. For example, what if a new road is added to a network? Answering this type of question requires geographic as well as other information.

GIS is not...

...simply a computer system for making maps, although it can create maps at different scales, in different projections, and with different colors. A GIS is an analytical tool. The major advantage of a GIS is that it allows you to identify the spatial relationship between map features. A GIS does not store a map in any conventional sense; nor does it store a particular image or view of a geographic area. Instead, a GIS stores the data from which you can draw a desired view to suit a particular purpose.