Geospatial Visualization

Urban Resilience

Ecological Resilience (Holling 1973)
- ... persistence of relationships in a system, ... and ability of system to absorb changes in state variables, driving variables, and parameters and still exist ...
- ... a measure of the amount of disturbance a system can take before collapsing into an alternate configuration ...
- Leads to Adaptive Management Cycles

Holling, C. S. (1973). Resilience and Stability of Ecological Systems. Annual Review of Ecology and Systematics, 4, 1-23.

Adaptive Management

Where do maps fit in this cycle?

Hess, Jeremy J., McDowell, Julia Z., & Luber, George. (2012). Integrating Climate Change Adaptation into Public Health Practice: Using Adaptive Management to Increase Adaptive Capacity and Build Resilience. Environmental Health Perspectives, 120(2), 171-179. doi: doi:10.1289/ehp.1103515

Urban Resilience

Urban resilience is the capacity of a city’s systems, businesses, institutions, communities, and individuals to survive, adapt, and grow, no matter what chronic stresses and acute shocks they experience.

The Wikipedia entry on Urban Resilience also has good definitions and resources.

What GIS data can we use to measure, analyze, or understand Urban Resilience??

Resilient Cities Network, https://resilientcitiesnetwork.org/what-is-resilience/, accessed 2021-10-04.

Data for Urban Resilience

Physical

Climate
- temperature
- air pollution
- rainfall
Geology
- foundation conditions
- unique or valuable deposits
Physiography
- slope
- riparian habitat
- surface drainage
Hydrology
- aquifers
- drainage basins
- recharge zones

Values

Scenic
- forests
- features
- riparian
- beaches
Development
- commercial
- residential
- industrial
- resource extraction
Conservation
- endangered species
- endemic species
- water
- soil

Land Use

Urban Zoning
- residential
- commercial
- industrial
- recreational
Historic
- buildings
- cultural sites
- educational
Recreational
- active
- passive
Conservation
- animal habitats
- ecosystems
- surface drainage

McHarg, Ian L. (1969). Design With Nature. Philadelphia: The Falcon Press.

Three [ 5 ] things we do with computers

[ load ]
Select
Manipulate
Save
[ repeat ]

Joins : or how to put data in a conversation

Vector - Vector
- contains: points or lines to polygon
- within: polygon attributes to points or lines
- intersects: vector attributes to polygons, points, or lines
Vector - Raster
- extraction: raster to points (i.e. elevation to tree locations)
- zonal statistics/histograms: raster to polygons (i.e. avg, max, and min elevation within property boundary)
Raster - Raster
- Raster math or raster algebra
- tool: raster calculator

Perhaps convert or aggregate before join

Vector to Vector
- buffer: distance from vector feature
- dissolve: combine features based on common attribute
- intersect, union, buffer, difference: mostly polygons and some lines
Vector - Raster
- interpolation: vector to raster (fills in pixels between with estimated values)
- rasterize: points lines or polygons to raster (no estimation)
Raster - Vector
- polygonize: raster to vector (draws polygons of raster features)
Raster - Raster
- resample: change pixel dimension
- crop/clip: reduce coverage of raster

Attribute Statistics and Aggregation

Basic column statistics available in GIS
Basic aggregation tools available in GIS
Sometimes you need to take results to other program
- export attribute table
- Python, STATA, R, Excel, other ...

So Many Tools ....

!CLICK ME!

Vector Analysis

Vector Operations (one layer)
Vector Operations (two layers)
Spatial Join
Attribute Statistics & Aggregation

One Layer Vector Operations

Buffer
Dissolve
Transformations (vector to raster)
Convex Hull
Centroids
Transformations (polygon to line or vice versa)
Voroni Polygons (fill plane from points)

One Layer Vector Operations - Buffer

ring buffer (one radius)
multiple-ring buffer (several radii)

image from: https://saylordotorg.github.io/text_essentials-of-geographic-information-systems/s11-geospatial-analysis-i-vector-o.html

More Buffers

variable width
multiple ring
doughnut
setback
non-dissolved
dissolved

image from: https://saylordotorg.github.io/text_essentials-of-geographic-information-systems/s11-geospatial-analysis-i-vector-o.html

One Layer Vector Operations - Dissolve

combines features based on attribute
useful for data aggregation
useful for cartography
- multiple line segments with same label (roads)
- remove duplicate polygon labels for area

image from: https://pro.arcgis.com/en/pro-app/latest/tool-reference/data-management/dissolve.htm

Two Layer Vector Operations
** Spatial Join **

Points in Polygon
Intersect
Join Attributes by Location
Union
Clip
Difference

Points in Polygon
Simple Spatial Join

one point layer and one polygon layer
counts number of points in polygon
point attribute aggregation possible > polygons
New "COUNT" column in polygon attributes

image from: https://datawanderings.com/2018/09/01/r-point-in-polygon-a-mathematical-cookie-cutter/

Intersect two layers

Can be lines or polygons
Boundaries from both layers
Attributes from both layers
May need to dissolve after to make sense of analysis

image from: https://pro.arcgis.com/en/pro-app/latest/tool-reference/analysis/intersect.htm

Join Attributes by Location

image from: https://gisgeography.com/spatial-join/

Join Attributes by Location
** Spatial Join **

combines attributes based on shared locations
- points in polygon)
- intersection
- other ...
example: attach tract ID to point data
example: summarize point data and attach to polygon

image from: https://gisgeography.com/spatial-join/

Join Attributes by Location
raster to vector or vice versa

Add attribute to vector data based on underlying raster values
Often call "extraction" or "extract"
Basic statistics from pixels inside polygon (review)
Often called "Zonal Statistics" or "Zonal Histogram"

image from: https://www.esri.com/arcgis-blog/products/analytics/analytics/how-to-extract-raster-values-at-point-locations/

Excercises

Polygon contains points
Points within polygon
Extract from raster at point

Spatial Join - TRI sites (points) in Census Tracts (polygons)

What FL census tracts have most TRI sites?

Get data from box folder (data management!)
- 2021_MD_CensusTracts_tiger.zip
- tri_2020_fl.csv
New project in ArcGIS Pro (or Q) and add both layers
Display x/y data for the TRI layer (projection!)
Spatial Join
- Target layer/features: tracts
- Join features: tri
- Join operation: one to one (keep all target features)
- *New Layer*: tracts_tri
- Match option: contains
Symbolize census tracts, remember:
- Graduated (on join count)
- kind of classification and number of breaks matters

Spatial Join - Census Tracts (polygons) to TRI sites (points)

What census tract is each TRI site in?

Same data as previous
New (or same) project in ArcGIS Pro (or Q) and add both layers
Display x/y data fro the TRI layer (projection!)
Spatial Join
- Target layer/features: TRI
- Join features: tracts
- Join operation: one to many (keep all target features)
- *New Layer*: tri_tracts
- Match option: within
Open attribute table and explore:
- This enables statistical analysis for the TRI layer as related to census tracts

Spatial Join - Extract elevation (raster) to trees (points)

What is the elevation of each tree?

Get data from box folder (data management!)
- UM_DEM_2021_5FT.tif
- UM_trees_20221004.zip
New (or same) project in ArcGIS Pro (or Q) and add both layers
Find "Extract Values to Points" tool in toolbox
Spatial Join
- Input points: trees
- Input raster: elevation (DEM)
- *New Layer*: trees_elevation
- check "interpolate" and "append" boxes
Open attribute table and explore:
- This enables statistical analysis for the tree layer
- You can also symbolize trees by elevation