GIS Development Project

This repository contains an application made to integrate QGIS with Django, utilizing the UMEP (Urban Multi-scale Environmental Predictor) QGIS plugin for spatial analysis and environmental modeling. The focus of the application is to estimate the mean radiant temperature (Tmrt) in complex urban environments using the SOLWEIG (SOlar and LongWave Environmental Irradiance Geometry) model.

The application is build with Django, which is a high-level web framework for building web applications using the Python programming language. This application runs on a local server, but technically it should be possible to transfer the framework in to a web server. QGIS and its processing tools and plugins are used in the majority of scripts to run spatial analysis and environmental modeling. The Urban Multi-scale Environmental Predictor (UMEP) is a climate service modeling tool, available as a plugin for QGIS.

Installation Guide

Prerequisites

A Linux based operating system

1. Install QGIS

Download and Install QGIS:
- Go to QGIS website to install QGIS.
Launch QGIS and Install UMEP Plugins:
- Open QGIS.
- Go to Plugins > Manage and Install Plugins.
- Search for "UMEP" and install both the UMEP and UMEP Processing plugins.
Restart QGIS:
- Ignore any warnings that may appear upon launching QGIS.
Close QGIS:

2. Set Up Conda Environment

Install Anaconda:
- Download and install Anaconda from Anaconda website.
Import the Conda Environment:
- Download the qgis311.yml file from the project repository.
- Open a terminal in the directory containing the qgis311.yml file.
- Run the following command to create the environment:
```
conda env create -f qgis311.yml
```
Activate the Conda Environment:
- Activate the environment with:
```
conda activate qgis311
```
Open QGIS from Conda:
- Launch QGIS from the terminal by typing:
```
qgis
```
Set the Processing paths
- In QGIS go to Settings > Options > Processing > Models
- Ensure that the Models folder is: /home/user/.local/share/QGIS/QGIS3/profiles/default/processing/models

3. Set Up the Project Files

Download the Project Files:
- Download the django_server folder from the project repository.
- Place it in the Documents directory on your local machine, so the path looks like: /home/user/Documents/django_server/.
- Download a DEM and DSM file from OneDrive. Place them in the /home/user/Documents/django_server/data/ directory.

Scripts and Leaflet Map

The application has scripts that use PyQGIS, UMEP processing plugin, and different Python libraries. The scripts have input and output paths that need to be modified. There is also an interactive map, where the user can draw a polygon, that will be used to crop the study area.

Leaflet Map

The map can be used to easily define the desired study area. After submitting the polygon, it will be used as input for cropping input data.

Output:
- polygon_data.geojson

crop.py

The script takes the user defined polygon, reprojects it, and crops the digital elevation model and digital surface model.

Input:
- DSM_Helsinki.tif
- DEM_Helsinki.tif
- polygon_data.geojson
  - The user drawn polygon.
Output: - croppedsm.tif
- croppedem.tif

skyviewfactor.py

The script creates skyviewfactor TIF files, shadowmats, wall heights, and wall aspects for input into the SOLWEIG analysis.

Input:
- croppedsm.tif
- croppedem.tif
Output:
- skyviewfactor.tif
- svf.zip
- shadowmats.npz
- wallAspect.tif
- wallHeight.tif

solweig.py

The script runs the SOLWEIG analysis, using the outputs from the previous scripts as input.

Input:
- croppedsm.tif
- croppedem.tif
- skyviewfactor.tif
- svf.zip
- shadowmats.npz
- wallAspect.tif
- wallHeight.tif
  - weather_umep.txt
Output:
- Tmrt_average.tif

view_image.py

The script uses Python Library Pillow to read in the tif file. Python library matplotlib is used to display the Tmrt_average.tif, created in the SOLWEIG analysis.

Input:
- Tmrt_average.tif

The following parameters can be changed by the user:

vmin
vmax
- These parameters define the range of the values displayed. It is recommended to keep vmin at 10 or less.
cmap
- The colormap can be set to the users preference. See: available colormaps in matplotlib.

Input Data

The DEM and DSM files can be downloaded from OneDrive.

DEM_Helsinki.tif

The digital elevation model (DEM) represents the grounds surface elevation.

Resolution: 1 meters
Format: GeoTiff
Coordinate system: EPSG:3879 - ETRS89 / GK25FIN
Elevation model of the City of Helsinki
- https://hri.fi/data/en_GB/dataset/helsingin-korkeusmalli

DSM_Helsinki.tif

The digital surface model (DSM) represents the grounds surface elevation and height of buildings.

Resolution: 1 meters
Format: GeoTiff
Coordinate system: EPSG:3879 - ETRS89 / GK25FIN
- Derived from the Elevation model of the City of Helsinki, using UMEP digital surface model generator.

weather_umep.txt

Weather data retrieved from the global the Coopernicus programme and Climate Data Store using UMEP's meteorological data download tool and the MetPreProcessor tool for formatting the data. Used in SOLWEIG analysis. In the data/weather_data directory, there are four weather data files from may to august in 2020. The desired data can be used by copying the file into the data directory and renaming it to weather_umep.txt.

The UMEP manual provides a guide on how to download more weather data: Meteorological Data: Download data (ERA5), and how to format it: Meteorological Data: MetPreprocessor.

How To Use

Before the application can be used, the scripts file paths need to be modified.

In /home/user/Documents/django_server/scripts all four scripts need to be modified. The /home/user/Documents/django_server/umep/views.py file needs to be modified. The files include filepaths /home/user/Documents/django_server/... where the user needs to be changed to match your local machines username.

The downloaded DEM_Helsinki.tif and DSM_Helsinki files need to moved to /home/user/Documents/django_server/data directory.

Open terminal in the Project Directory:
- Open a terminal in the root of the Django project, where manage.py is located.
Activate the Conda Environment:
- Activate the Conda environment by running:
```
conda activate qgis311
```
Collect static files
- Ensure that the applications css files are loaded by running:
```
python manage.py collectstatic
```
Run the Django Server:
- Start the Django development server with:
```
python manage.py runserver
```
Access the Application:
- Open your browser and go to http://127.0.0.1:8000/umep/ to access the application.
Click on Select Area for SOLWEIG

A map view will open.
Use the drawing tools on the left hand side to draw a single polygon representing the area where the anaylsis will be run.
Once the polygon has been drawn, press Submit Polygon.
A message will appear, telling that the polygon was saved succesfully.
Use browsers back button to get back to the main page.

Click on Crop Data

Wait for the script to finish.
A message will appear, telling that the script has been ran succesfully.
Use browsers back button to get back to the main page.

Click on Create Skyviewfactors and Wall Aspect and Ratio

Wait for the script to finish.
A message will appear, telling that the script has been ran succesfully.
Use browsers back button to get back to the main page.

Click on Run SOLWEIG

Wait for the script to finish.
A message will appear, telling that the script has been ran succesfully.
Use browsers back button to get back to the main page.

Click on View Result

A new window will open with a png image of the result.

The tif files of the SOLWEIG output can be retrieved from /home/user/Documents/django_server/data/output/solweig

saarinna/gisdev