ESRI Guide to GIS Analysis Ch. 4 & 5

Chapter 4: Mapping Density

 Why map density?

Shows you were the highest concentration of landmarks/features are and are useful when mapping areas of different sizes. Mapping density is useful when mapping areas that vary in numbers.

 

Shade areas based on density value

  • Think about the features your mapping and what information you have

 

Data type

  • Mapping the density of points and lines (per square mile)
  • Map features (locations of businesses)
  • Map features values (the number of employees at each business)

 

Two ways to mapping density:

  1. Mapping density for defined areas (dot density for individual locations) and mapping density value for each area (zip codes by shading)
  2. Creating a density surface (raster layer) each cell in a later get a density value

 

 

Chapter 5: Finding What’s Inside

Why map what’s inside?

“To monitor what’s occurring inside it, or to compare several areas based on what’s inside.”

 

Are you finding what’s inside a single area or each of several areas?

Single Area:

  • “Lets you monitor activity or summarize information about the area”

Multiple Areas:

  • Finding how much of something is in several different areas aloowing you to compare the different areas.

 

Discrete features within an area:

  • Unique, identifiable features
  • List, count or summarize a value associated with them
  • Examples: locations (crimes), linear features (streams, roads, pipelines), areas (parcels)

 

Information needed for analysis:

  • Feature Attributes

 

Three Ways to Find What’s Inside:

  1. Drawing the areas and features
  2. Selecting the features inside the area
  3. Overlaying the areas and features
By sjkeen

Delaware GIS Data Excercise

Metadata is information that describes specific features/items in ArcGIS.. When care is taken to provide good descriptions, you can find appropriate items with a search and evaluate which of the items in your search results is the correct one to use. In an item’s metadata you can then record whatever info is important for your audience to know about that item. This might include information about how accurate and recent the item is, restrictions associated with using and sharing the item, etc. Metadata is critical for sharing tools, data, and maps and for searching to see if the resources you need already exist. Any item in ArcCatalog, including folders and file types such as Word documents, can have metadata.

Delaware_2008 and 2010 Ponds and Lakes:

  • This layer contains data where the different ponds and lakes are in Delaware County. This may be relevant to the Delaware run possibly.

Delaware_Address_Pts:

  • This has data on all of the addresses in the county of Delaware.

Delaware_Annexations:

  • I am confused about this data, I may ask about it later.

Delaware_Archeological:

  • Shows archeologist’s area of historical cites where physical remains and the analysis of artifacts have taken place.

Delaware_Bench_Marks:

  • On ArcGIS this shows all of the places in Delaware County where there are official benchmarks that can be used as geographical references.

Delaware_Building Outlines:

  • This layer allows one to see every building that is in the county, and you can use the information feature in the “select by attribute” tab to determine what kind of building it is, e.g. residential, commercial, etc.

Delaware_ Census_Block:

  • None

Delaware_ Census_BiockGroup:

  • None

Delaware_ Census_ Tract:

  • A survey of a population within a geographic area that is defined.

Delaware_Economic Development Layers:

  • This shows all of the development projects that are currently in progress.

Delaware_Farmlots:

  • These layers consist of all of the farm lots.

Delaware_Floodplain_1OOyr:

  • Shows the extent of 100-year flood plains around different bodies of water in Delaware County. Delaware run group for sure!

Delaware_Floodplain_500yr:

  • Shows the extent of 500-year flood plains around the county.

Delaware_Floodplain_2009:

  • Displays places in the county that are at risk of being flooded

Delaware_Floodways:

  • Bodies of water that are risk of flooding, and where it would flow. Flood plane?

Delaware_Historical_Local:

  • Allows points of local historical interest to be viewed on a map

Delaware_Historical_National:

  • This dataset contains points of national historical interest, and where there are physical markers.

Delaware_Hydro:

  • Shows the locations of major bodies of water in Delaware County.

Delaware_Hydro_Detail:

  • Lists all of the bodies of water, from small ponds to the big bodies.

Delaware_Landmarks:

  • Schools to parks to cemeteries to fire stations, etc.

Delaware_Master Point Coverage:

  • Very similar to the address points layer. Don’t know how I would need this

Delaware_Municipalities:

  • The different municipal areas of the county, such as the city of Delaware, Sunbury, Powell, etc.

Delaware_Natural_Heritage_ ODNR:

  • Just individual points on the map.

Delaware_ Orthophoto _Detailed_2010:

  • This layer holds much newer satellite imagery of Delaware. I think most groups will be using this one. I think the drone group is updating this.

Delaware_Parcels:

  • This dataset contains data on every parcel in the county, and who owns that parcel in a lot of cases.

Delaware_Parks:

  • Maps all the park locations in Delaware County.

Delaware_Places of Interest:

  • Similar to the Landmarks dataset, similar locations. Golf courses, medical centers, mobile home parks, police stations, post offices, public buildings, and schools.

Delaware_Precincts:

Delaware_Public Land Survey System:

  • This dataset puts a grid on the map of all the individual sections that have been surveyed. They are split up into squares for the most part, like the USGS quadrangles.

Delaware_Railroad:

  • Shows the railroads in the county.

Delaware_Road_Center_Line:

  • Displays all of the roads with a single line for each road.

Delaware_Road_RightOfWay:

  • Somehow shows the right of way on the roads. I don’t know how to interpret it though…I guess I’m going to end up going the wrong way on some streets.

Delaware_School_Districts:

  • This splits the county up into all of the different school districts. You could add on the address layer and see what addresses match up with what districts, and determine who goes where for school.

Delaware_Soils:

  • This seems like a very complex dataset, consisting of a lot of information on the different soil types in the county.

Delaware_Subdivision:

  • They are parcels that are their own, well, subdivisions. I guess a subdivision is a classification.

Delaware_ TaxDist:

  • Splits the county into the different tax districts.

Delaware_ Topography:

  • Puts a raster layer of shaded relief topography. It gets blurry when you zoom in, as is expected of raster data.

Delaware_ Townships:

  • Displays the different townships in the county

Delaware_ Townships_Historical:

  • It’s the same as the previous, but less dense and maybe an older version.

Delaware_ Watersheds_ ODNR:

 

Delaware_ Wetlands:

Delaware_ Woodland_ ODNR:

  • Shows wooded areas of Delaware County.

Delaware_Zip_Codes:

  • Shows where the geographical cutoffs are for the different zip codes in the county.

Delaware_Zoning:

  • None

Ohio Wesleyan Parcels:

  • OWU campus.

Watershed-Scioto:

  • This dataset shows the full extent of the Scioto River watershed, extending outside of Delaware County.
By sjkeen

ESRI Guide to GIS Analysis Ch.1

What Is GIS Analysis?

Wikipedia:

  • “A geographic information system (GIS) is a computer system designed to capture, store, manipulate, analyze, manage, and present all types of geographical data. The acronym GIS is sometimes used for geographical information science or geospatial information studies to refer to the academic discipline or career of working with geographic information systems and is a large domain within the broader academic discipline of Geoinformatics.”
  1. Frame The Question
  • You need to determine first what data you need. Determine how it’s going to be used and by whom. Be Specific.

 

  1. Understand your data
  • Knowing what kind of data and the features you are working with helps you to determine the method to use.

 

  1. Choose a method
  2. Process the data
  • Apply the necessary steps in GIS.
  1. Look at the results
  • Once you have entered the information into GIS evaluate the results and see how it relates to the original question or hypothesis.

 

Understanding Geographic Features

Types of features:

  • Discrete features:
  • Continuous phenomena
  • Features summarized by area

 

Two ways of representing geographic features

  • Raster and vector are the two basic data structures for storing and manipulating images and graphics data on a computer. Raster data is represented as a matrix of cells in space; the specific cell size used will affect the results of the analysis as well as how the map is presented. Raster data usually goes alongside continuous data; some good examples would be the average temperatures for a specific area. Vector data is usually represented by discrete data such as land parcels, center of road lines, or specific address points.

 

*Check coordinate systems and map projections for each map layer and make sure they are they same.

By sjkeen

The ESRI Guide to GIS Analysis: Chapter 6 & 7

Chapter 6: Finding Whats Nearby

Why map whats nearby?

  • To find whats within a set distance of a feature–this identifies the area, and what features are in this area.
  • To find out what is within traveling range–using time, distance, or cost. This is can be very useful when going on a road trip or for fire departments finding the quickest way to a fire.

Defining Whats Nearby

  • Set distance: find what restaurants are within 20 miles of where you live,.
  • Travel route: What restaurants are between OWU and Ohio State.
  • Travel Cost: How much gas are you willing to burn, could depend on what type of food you are trying to find, or how much gas is in the tank.

In GIS, once you find the features that are nearby, you can create a list of the addresses and then mark them on the map to show how nearby they are.

Three Ways of Finding Whats Nearby:

1.)  Straight-Line Distance

  • “With straight-line distance, you specify the source feature and the distance, and the GIS finds the area or the surrounding features within the distance” (121).
  • This is good for creating a boundary or selecting features at a set distance around a source.
  • What you need–A layer containing the source feature, and a layer containing the surrounding features.

2.)  Distance or Cost Over a Network

  • This is good for finding what’s within a travel distance or cost of a location, over a fixed network.
  • What you need–locations of the source features, a network layer, a layer containing the surrounding features. Each segment of the network needs to attribute to the length or cost value.

3.)  Cost or Surface

  • “You specify the location of the source features and a travel cost” “The GIS creates a new later showing the travel cost from each source feature” (121).
  • This is good for calculating overland travel cost.
  • What you need–a layer containing the source features and a raster layer representing the cost surface.

Chapter 7: Mapping Change

“People map what’s changed to anticipate future conditions, decide on a course of action, or to evaluate the results of an action or policy” (150).

Examples of mapping change

  • a police chief might study how crime patterns have changed from month to month to help decide where to patrol.
  • drug trafficking can also be mapped, by mapping the narcotics arrests that happen, you are able to see weather one drug looms larger in specific areas; then the police then know what to predominantly look for in that area.
  • Air quality
  • Weather patterns
  • Erosion
  • Population

Defining Change in Maps:

  • Change in Location–helps you see how features behave and predict how they will change from location to location. Weather changes depending on elevation, wind, and many other things. Therefore a storm changes as is moves from one state to another or even one town to another.
  • Change in Character or Magnitude–shows how conditions in a given place have changed.

The Geographic Features

  1. Features that move:
  • “You can map discrete features that physically move, or events that represent geographic phenomena that change location” (153)
  1. Features that change in character or magnitude:
  • “You can map change in character or magnitude for discrete features, data summarized by area, continuous categories, or continuous numeric values” (153).

Measuring Time

The time pattern and time period being dealt with affects the geographic patterns you see on your map.

There are three types of time patterns

  1. A trend–change between two or more dates or times
  2. Before and After–conditions preceding and following an event
  3. A cycle–change over a recurring period of time, such as a day, month, or year.

Three Ways of Mapping Change

  1. Creating a Time Series
  • This is good for showing changes within boundaries, values for discrete areas, or surfaces.
  • You create one map for each time or date showing the location or characteristics of the features.
  1. Creating a tracking map
  • This is good for showing movement in discrete locations, linear features, or area boundaries.
  • You create a single map showing the locations of features at several dates or times.
  1. Measuring and mapping change
  • this shows the amount, percentage, or rate of change in a place.
  • You calculate the difference in the amount of a category or in the value of a numeric attribute, and display the features based on these values.
By sjkeen

Intro

My name is Sam Keen, and I am a Junior from Evergreen, Colorado. I enjoy skiing in the Winter and rafting in the Summer. With a very diverse landscape: from dessert in the south, plains in the East, and mountains in the West; there is a lot to map out in Colorado.

s_c01_56466043

What interests me about this class is the many varieties in which GIS is used today. All sorts of companies use this software and I am excited to learn as much as possible this semester.

Colorado is a great state for GIS; Skiing is Colorado’s greatest attraction and the Rocky Mountains are the perfect backdrop. GIS has helped many of these resorts configure their layout and map out their trails. This interests me  a lot and I am excited to learn more.

By sjkeen

GIS Applications

 

GIS software is like a blank book, or a painting before it is painted; layer by layer the creator or artist gets to choose what he or she wants to show on their map. From bodies of water, population, roads, hiking trails, natural resources, building plans, etc.

I researched some uses for GIS software and thousands of ideas popped up…

Sports:

Who watches college basketball?

ESRI-College-Basketball-Map

http://www.sportsnationdivided.com/2012/01/25/map-of-the-week-gis-and-college-basketball/

Water:

The Colorado Division of Water Resources provides a variety of Geographical Information System (GIS) and Mapping solutions, many of which are available for download or online viewing, free of charge.

Oil:

GIS technology has been used in ‘conventional’ petroleum for many years and is now being used increasingly in the development of continuous ‘unconventional’ resource plays such as shale gas, shale oil and coal bed methane.

Construction/Architecture:

Examples:

I also searched and found three real life examples of how some big corporations used GIS software to establish efficiency and another viewing experience within their line of work.

  •  One firm’s approach to GIS data management is refining FEMA’s Flood Insurance Rate Mapping (FIRM) process.
  • Colorado Springs Utilities (CSU)
  • GIS provides local government with time and cost-saving benefits for better management of zoning data.
By sjkeen