代做GGRA30: Geographic Information Systems (GIS) and Empirical Reasoning Assignment #2帮做数据库编程

GGRA30: Geographic Information Systems (GIS) and Empirical Reasoning

Assignment #2: QGIS Familiarization and Vector Data

Fall 2024

1 Learning Objectives

When you complete this assignment you will have demonstrated:

•  the ability to load vector data into QGIS from a PostgreSQL / PostGIS database.

Assignment #2 GGRA30 Fall 2024

•  the ability to create and export a map as a letter-sized PDF using QGIS, including configuring layer ordering, layer styles, and labels.

• the ability to examine attributes for vector data and answer questions about the data.

Practical #3 (Week 4) introduces the QGIS user interface (UI) and describes the procedure to create and export a map layout as a Portable Document Format (PDF) file.  Practical #4 (Week 5) presents information about connecting to a PostgreSQL / PostGIS database to access geographic information and about styling vector layers and map elements using QGIS.

Your Neighbourhood for Mapping For this assignment, you are going to create a basic map showing a specified neighbourhood in Toronto within its surroundings.  Table 1 shows which neigh- bourhood you must map, depending on the last digit of your student number.  The neighbourhood names can be found in the area_name field of the toronto_neighbourhoods layer.

Table 1: Neighbourhood assignments, according to the last digit of your student number.

2 Data Provided

The data you are to use for this assignment has been provided in the form of an online PostgreSQL / PostGIS database:

•  server: ggrgis.utsc.utoronto.ca

•  database: ggra30_a2

• username: ggra30

•  password: ggra30

Practical #4 (Week 5) includes instructions for connecting to a similar database on the same server, and for loading and configuring vector layers. This database includes the following layers, all of which are derived from data provided by the City of Toronto except for the lake_ontario_area layer that was derived from Statistics Canada 2016 Census reference data, modified using City of Toronto data:

• lake_ontario_area: a vector polygon layer with a generalized outline of Lake Ontario (in case a map of your neighbourhood shows part of the lake).

• toronto_major_streets: a vector line layer containing information about major roads in Toronto. These represent the road centre lines. Smaller residential roads are not included.

Assignment #2 GGRA30 Fall 2024

• toronto_neighbourhoods: a vector polygon layer containing information about City of Toronto neighbourhoods.

• toronto_parks: a vector polygon layer containing information about city parks in Toronto.

• toronto_res_zones: a vector polygon layer containing outlines of residential zones in each Toronto neighbourhood.

• toronto_water_lines: a vector line layer containing information about rivers and creeksin Toronto As with the streets layer above, these lines represent the centre line of rivers and creeks.

All of the layers listed above should be used in your map. See the sample map at the end of these in- structions. None of the layers provided for Practicals #3 and #4 (the web service tiles and the Ontario boundary, water and weather stations layers) maybe used to complete your assignment map.

3 Assignment Submission

You will submit digital files, one containing your completed map (Section 4) and the other containing your typed answers to the questions in Section 5.  Both files must be PDFs:  Export a map PDF from QGIS and export your written answers as PDF from your writing program (e.g., Word).  Ensure your name and student number are in each document.

4 Create and Export a PDF Map: 12 Marks

Your task in this assignment is to create a map layout similar to the sample attached to this assignment handout.  As shown in that sample, you should be able to distinguish different area types by colour. Choose colours that make sense to you and don’t worry about trying to create a replica of the sample by using the same colours. Once complete, you will export the map from QGIS as a PDF to be uploaded as part of your assignment submission.

Include all of the following map elements:

•  Title

•  Legend

•  North arrow

•  Scale bar (sized so that it shows round number distances)

•  Your name and student number

•  Labels for neighbourhoods (especially your assigned neighbourhood but also those around that neighbourhood if space allows); major roads,and, if possible, parks although some of these will be too small at the scale mapped to label and that is okay.

The instructions for practicals #3 (Week 4) and #4 (Week 5) include all of the instructions required to complete this assignment. They are not repeated here.

1You can reduce repeated road labels by adjusting labelling settings to treat multiple segments of the same road as a single feature (“Merge connected lines to avoid duplicate labels”). Check the label configuration options, especially under the placement and rendering tabs. https://docs.qgis.org/3.34/en/docs/user_manual/style_library/label_ settings.html

Assignment #2 GGRA30 Fall 2024

4.1 Organize the Data Layers

Add all of the layers provided in the assignment database to the map. Reorder the layers:

•  Order the neighbourhood boundaries on top of the roads.

•  Order the roads over the water lines.

•  Order the polygon layers (parks, residential zones, and water area if used) under the line layers.

Note that to draw the neighbourhood boundaries on top of the roads which are on top of the water lines, you need to ensure that the neighbourhood polygons are not filled with any colour so a viewer can “see through” the layer. This has been done in the attached sample (p.6) to make the neighbour- hood shape stand out from the roads that often form. parts of the neighbourhood boundary. See layer styling instructions in Practical #4 for information about configuring the “fill style” of polygon layers.

4.2 Map Page Layout

Design and export your map for letter size paper. Whether you create your map in portrait or landscape mode is up to you and will mainly depend on which neighbourhood you have been assigned and how the shape of that neighbourhood fits the page. Try to fill you map with the assigned neighbourhood as shown in the sample at the end of these instructions. The boundary of your neighbourhood must be completely visible — fit in on the page and don’t layer other map elements on top of boundary sections.

Your map page should be set up as follows:

•  Use .75 in (19.1mm) margins all around the map.

• The map should be 7 in (17.78 cm) x 9.5 in (24.13 cm).

•  All map elements (legend, scale bar, titles, etc.) must be inside the map area. Do not place any of these map elements in the margins. Your Teaching Assistants and I use the margins for marking.

5 Questions: 6 Marks

Answer these questions in your written report.

1.  (1 mark) In the data provided, what are the names of the neighbourhoods (area_name field) that are sequentially before and after your assigned neighbourhood when the neighbourhoods are sorted into ascending order by numeric neighbourhood code (nid field). Briefly explain how you found this answer.

2.  (1 mark) In the data provided, what is the name (area_name field) of the the neighbourhood that is next larger than your assigned neighbourhood according to the area_sqm field values? Briefly explain how you found this answer.

3.  (2 marks) A neighbourhood feature (feature in the toronto_neighbourhoods layer) and the fea- ture in the toronto_res_zones layer contained by that neighbourhood have the same numeric identifier (nid), allowing you to (manually) match up the records for a single neighbourhood in those data layers. Using the layers provided, calculate the percentage of your assigned neigh- bourhood’s area that is zoned for residential use. Briefly explain how you answered this question.

Assignment #2 GGRA30 Fall 2024

4.  There is only rudimentary information included in the data layers provided for this assignment but the neighbourhoods are identified using standard ID (nid) and names that match other in- formation available from the city. In particular, the city provides Neighbourhood Profile data that compiles a variety of information about each of the neighbourhoods. Among other formats, this data is available as comma-separated-values (CSV) files, one for each recent Statistics Canada Census. CSV files are readable text files containing tabular data that can be opened in Excel.

Download the 2016 neighbourhood profile CSV file from https://open.toronto.ca/dataset/ neighbourhood-profiles/to answer the following questions. The CSV is organized with vari- ables in rows and the values for each neighbourhood comprises a column in the spreadsheet. Column E contains “variable characteristics” for each variable — use this column to identify the row containing the variable I ask about below.

(a)  (1 mark) Find the 2016 populations. What was the 2016 population for your assigned neigh- bourhood?

(b)  (1 mark) What is the population density of the residential area in your assigned neighbour- hood?  Calculate this using the total residential area within your neighbourhood, as given by the attributes in the toronto_res_zones layer.

As a reminder, the formula for calculating the density of countable entities is:

density = area they are in/number of entities                    (1)

Provide your answer in units of people per sq. kilometre. BTW, I know that the neighbour- hood profile includes a population density for the entire neighbourhood. I’m asking for the density calculated only over the residential area so you will have to calculate this yourself.