Geovisualization of Crime in the City of Toronto Using Time-Series Animation Heat Map in ARCGIS PRO

Hetty Fu

Geovis Project Assignment @RyersonGeo, SA8905, Fall 2019

Background/Introduction

The City of Toronto Police Services have been keeping track of and stores historical crime information by location and time across the City of Toronto since 2014. This data is now downloadable in Excel and spatial shapefiles by the public and can be used to help forecast future crime locations and time. I have decided to use a set of data from the Police Services Data Portal to create a time series map to show crime density throughout the years 2014 to 2018. The data I have decided to work with are auto-theft, break and enter, robbery, theft and assault. The main idea of the video map I want to display is to show multiple heat density maps across month long intervals between 2014 to 2018 in the City of Toronto and focus on downtown Toronto as most crimes happen within the heart of Toronto.

The end result is an animation time-series map that shows density heat map snapshots during the 4-year period, 3-month interval at a time. Examples of my post are shown at the end of this blog post under Heat Map Videos.

Dataset

All datasets were downloaded through the Toronto Police Services Data Portal which is accessible to the public.

The data that was used to create my maps are:

  1. Assault
  2. Auto Theft
  3. Robbery
  4. Break and Enter
  5. Theft

Process Required to Generate Time-Series Animation Heat Maps

Step 1:  Create an additional field to store the date interval in ArcGis Pro.

Add the shapefile downloaded from the Toronto Police Services Portal intoArcGIS Pro.

First create a new field under View Table and then click on Add.             

To get only the date, we use the Calculate Field in the Geoprocessing tools with the formula

date2=!occurrence![:10]  

where Occurrence is the existing text field that contains the 10 digit date: YYYY-MM-DD. This removes the time of day which is unnecessary for our analysis.

Step 2: Create a layer using the new date field created.

Go into properties in the edited layer. Under the time tab, place in the new date field created from Step 1 and enter in the time extent of the dataset. In this case, it will be from 2014-01-01 to 2018-12-31 as the data is between 2014 to 2018.

Step 3: Create Symbology as Heat Map

Go into the Symbology properties for the edited layer and select heat map under the drop down menu. Select 80 as its radius which will show the size of the density concentration in a heat map. Choose a color scheme and set the method as Dynamic. The method used will show how each color in the scheme relates to a density value. In a Dynamic setting versus and constant, the density is recalculated each time the map scale or map extent changes to reflect only those features that are currently in view. The Dynamic method is useful to view the distribution of data in a particular area, but is not valid for comparing different areas across a map (ArcGIS Pro Help Online).

Step 4: Convert Map to 3D global scene.

Go to View tab on the top and select convert to global scene. This will allow the user to create a 3D map feature when showing their animated heat map.

Step 5: Creating the 3D look.

Once a 3D scene is set, press and hold the middle mouse button and drag it down or up to create a 3D effect.

Step 6: Setting the time-series map.

Under the Time tab, set the start time and end time to create the 3 month interval snapshot. Ensure that “Use Time Span” is checked and the Start and End date is set between 2014 and 2018. See the image below for settings.

Step 7: Create a time Slider Steps for Animation Purposes

Under Animation tab, select the appropriate “Append Time” (the transition time between each frame). Usually 1 second is good enough, anything higher will be too slow. Make sure to check off maintain speed and append front before Importing the time Slider Steps. See below image.

Step 8: Editing additional cosmetics onto the animation.

Once the animation is created, you may add any additional layers to the frames such as Titles, Time Bar and Paragraphs.

There is a drop down section in the Animation tab that will allow you to add these cosmetic layers onto the frame.

Animation Timeline by frames will look like this below.

Step 9: Exporting to Video

There are many types of exports the user can choose to create. Such as Youtube, Vimeo, Twitter, Instagram, HD1080 and Gif. See below image for the settings to export the create animation video. You can also choose the number of frames per second, as this is a time-series snapshot no more than 30 frames per second is needed. Choose a place where you would like to export the video and lastly, click on Export.

Conclusion/Recommendation/Limitation

As this was one of my first-time using ArcGIS Pro software, I find it very intuitive to learn as all the functions were easy to find and ready to use. I got lucky in finding a dataset that I didn’t have to format too much as the main fields I required were already there and the only thing required was editing the date format. The number of data in the dataset was sufficient for me to create a time series map that shows enough data across the city of Toronto spanning 3 months at a time. If there was less data, I would have to increase my time span. The 3D scene on ArcGIS Pro is very slow and created a lot of problems for me when trying to load my video onto set time frames. As a result of the high-quality 3D setting, I decided to use, it took couple of hours to render my video through the export tool. As the ArcGIS Pro software wasn’t made to create videos, I felt that there was lack of user video modification tools.

Heat Map Videos Export

  1. Theft in Downtown Toronto between 2014-2018. A Time-Series Heat Map Animation using a 3 month Interval.
  2. Robbery in Downtown Toronto between 2014-2018. A Time-Series Heat Map Animation using a 3 month Interval.
  3. Break and Enter in Downtown Toronto between 2014-2018. A Time-Series Heat Map Animation using a 3 month Interval.
  4. Auto Theft across the City of Toronto between 2014-2018. A Time-Series Heat Map Animation using a 3 month Interval.
  5. Assault across the City of Toronto between 2014-2018. A Time-Series Heat Map Animation using a 3 month Interval.

Toronto Theft: A Neighbourhood Investigation

Geovis Project Assignment @RyersonGeo, SA8905, Fall 2019

By: Julia DiMartella-Orsi

Introduction:

ESRI’s creation of the Story Map changed the way we could visualize data. Not only did it allow for a broader audience to interact and create their own maps due to its easy to use design, it also contained many new amazing functions, templates, and themes. Users can personalize their story by adding in their own images, text, videos, and map layers by creating their own free ArcGIS Online account. Popular templates include Map Series, Tour, Journal, and Cascade.

Get started making your own Story Map here: http://storymaps-classicqa.arcgis.com/en/app-list/

Creating Your Story Map:

Once you have selected the template you want to use the choice is up to you. By clicking the “+” symbol you can choose to include text, media sources such as a videos, a new title page, or immersive content such as a web map.

ESRI also designed Story Maps to link to outside content and various social media sites such as Flickr and Unsplash. ‘Link to Content’ is also extremely useful as it allows users to add photos and videos found on the internet directly to their story map by copying and pasting their link.

To add interactive web maps into your story map users can link map layers from their ArcGIS Online account. Layers can be created in ArcGIS Online, but also in ArcMap where layers are exported as a zip file and imported onto your ArcGIS Online base map. Map layers can also be found online using the ‘add layer from the web’ or ‘search for layers’ options.  The layers that appear are based on the type of ArcGIS Online account you have created. Enterprise accounts contain additional layers provided by your organization, however ESRI also has free downloadable layers available for users without an organization.

Users also have the option to make their story maps public by clicking the globe icon, or private for their own personal use by clicking the lock icon. To save your story map select the floppy disk icon. Your saved map will appear under ‘My Content’ in your ArcGIS Online account.

My Story and Creating Web Maps:

Over the last few years, theft in Toronto has been increasing at a rapid rate. According to the Toronto Police Service, Toronto experienced a total of 5430 thefts between 2014-2018. However, these are only those that have been reported and documented by police. In order to analyze the distribution of theft across the city, the Toronto Police created a point dataset that summarized when and where each theft took place. Additional datasets were also created for prominent types of theft such as bicycle and auto theft.

To compare the number and types of theft in each Toronto neighbourhood I decided to create a story map using the Cascade template. This created a scrolling narrative that would allow viewers to observe the data in a clear, unique way. The reason why I chose to use a story map was due to the number of layers I wanted to compare, as well as use the ‘swipe tool’ to easily compare each neighbourhood. Therefore, I created a series of choropleth maps based on the 2014-2018 theft/crime data from the Toronto Police Open Data Portal.

The following steps were used to create each web map used in my Story Map:

Step 1: Download the point data and add the layer into ArcMap.

Step 2: Use the ‘spatial join’ analysis tool and select your neighbourhood boundary file as the target layer and the theft point data as the join feature. Make sure to select ‘join one to one’. This will produce a new layer with a ‘count’ field that counts the number of thefts in each neighbourhood – each neighbourhood is given a count.

Step 3: In order to produce accurate results, you must normalize your data. To do so add a new field into your attribute table (same layer with the count field) titled ‘Area’, and right click to select ‘calculate geometry’. Change the property to ‘area’ and choose the units you wish to use. Click ‘ok’ and the results will populate your new field.

Step 5: Export the layer and save it as a compressed zip folder. Import the data into ArcGIS Online by clicking the “Add” tab.

Step 6: Once you import your layer you are given a variety of styles to choose from. Select the one you like best (ex: choropleth) as well as the field you wish to map – in this case select ‘count’. To normalize ‘count’ select the ‘divided by’ dropdown and choose your ‘Area’ field. Change the colour of your map to your preference by clicking ‘symbols’.

Step 7: Save your layer to and select the tags that relate to your topic. The layer will now appear in ‘My Content’ where it can be added to your Story Map.

Step 8: To compare each layer add both layers you wish to compare to your story map by using the “+” symbol. Once you have done so, choose the transition type (ex: horizontal swipe) you want to use by clicking on the arrow below. The transition will take place as the user scrolls through your story map.

My Story Map titled “Toronto Theft: A Neighbourhood Investigation” can be viewed here:

https://arcg.is/uiemr