The Step-by-Step Instructions will guide you through the Sketch Map Tool and provide useful recommendations.
You can also download and print the manual.

Answers to the Frequently Asked Questions can be found in the FAQ section below.

Our new training platform provides five distinct training exercises to further explore the Sketch Map Tool and sketch mapping in general. These exercises are primarily designed for workshop settings, allowing for collaborative discussion of your experiences.

Since the latest version of the Sketch Map Tool was only recently released, you may encounter issues at various stages of the process. We apologize for any inconvenience this may cause. We are committed to continually enhancing the tool, so please report any technical problems to the Sketch Map Tool user support

Step-by-Step Instructions

1
Create paper maps to collect data
1.1 Define your area of interest and choose a base map layer

The first step in using the Sketch Map Tool involves creating a printable Sketch Map.

  1. Begin by selecting your area of interest, either by zooming into the map preview or using the search function in the sidebar.
  2. Choose between the two different base map layers: one based on OpenStreetMap (OSM) and the other containing satellite imagery (ESRI world imagery)
  3. Select from different paper formats and the appropriate page orientation. The dashed red line represents the boundaries of your area of interest, which will be printed on the Sketch Map.
  4. Initiate map creation by clicking the blue "next" button.
Screenshot of the Sketch Map Tool.
Recommendations:
  • Tailor the extent of your selected area to suit your use case, keeping the following questions in mind:
    • What do the participants need to map?
    • What details need to be visible on the map, and at what level of detail?
    • Which areas should the map encompass?
  • Aspects to consider when selecting the area of interest:
    • Ensure orientation on the map: streets (and their names) and some points of interest (POIs) should be visible.
    • Cover all relevant areas for your use case: for example, if studying flooding, focus on areas near rivers, creeks, sinkholes, and critical infrastructure that might be affected by the flood event.
    • For urban flooding, it is recommended to generate a map on the neighborhood level with streets and buildings. For river flooding, it is recommended to generate a map for a larger extent.
  • Choose a fitting base map for your mapping. The decision between the OSM or satellite image base map depends on factors like your selected area, the quality of OSM data, your participants, and what you would like to map. Sometimes, especially if the satellite image is very dark (e.g., due to large forest areas on the map), it can be helpful to create two Sketch Maps with both base map layers: Satellite and OSM.
  • Customize map format to fit your purpose:
    • Group mapping is easier on larger maps (A2 or A1, depending on your group size).
    • For data collection in the field, A4 or A3 are easier to handle. If the area is too big, consider creating multiple Sketch Maps.

If you like to learn more about the challenges of map orientation and how to choose a good base map, take a look at Training Exercise 2.

1.2 Map Quality Check

You can use OpenStreetMap(OSM) as a base map for the generated Sketch Maps. The Map Quality Check assists in evaluating the suitability of the area of interest for participatory mapping through a quality analysis of the OSM data with the HeiGIT ohsome quality analyst. The fitness report can be downloaded as a PDF file by clicking on the blue button. It provides an evaluation of the suitability of the local OSM data and recommendations for subsequent field data collection.

Map Quality Report.
Recommendations:
  • Before you use these OSM-based maps for participatory mapping in your area of interest, review the analysis provided by the Map Quality Check to ensure that participants can orient themselves properly on the paper maps.
  • The analyses focus on Point of Interest (POI) density, the last edit of amenities and streets, used sources, as well as the saturation of amenity and road network mapping. Detailed information about each indicator and the analysis is available in the generated PDF report.
  • The report includes useful recommendations to ensure that the generated maps are suitable for participatory mapping.
  • In case the OSM data in your area of interest is not sufficient for participatory mapping, consider consulting the Missing Maps project to improve the OSM data before using the Sketch Map Tool.
  • Take a look at the map:
    • How well can you orient yourself on the map?
    • Are important points of reference, such as hospitals, schools, landmarks, etc. visible on the map?
1.3 Export Sketch Map as PDF

The generated Sketch Map for your selected area of interest can be downloaded as a PDF file by clicking on the blue button.

Empty Sketch Map, OSM
Recommendations:
  • Name your scans/photos appropriately when saving, and before uploading them to the Sketch Map Tool. This helps you recognize and allocate your Sketch Maps in the subsequent uploading and analyzing process. If you relate Sketch Maps back to questionnaires, use the same number for the map as you did in the questionnaire.
  • Prepare separate maps for each topic or per person/group because it is difficult to read and analyze too many markings from one map. You can print out one map layout as often as you want.
  • We recommend printing the maps on matte, non-reflective paper.
  • If you plan on printing our your map in black and white, check the visibility of the background map and reduce saturation in the printing settings if the background becomes too dark.
  • In case you use a satellite imagery background, please review the color saturation of your image. If the background is too dark, you might consider to choose OSM as base map.
THEN:  Data collection in the field

The Sketch mapping with pens and the printed map is the key part of the Sketch Map Method. How you mark the maps influences your results and what can be detected. Here you can find here some recommendations for your data collection.

Example of marked map:

Empty Sketch Map, OSM
"Empty Sketch Map, Base Map: OpenStreetMap"
  1. Tips to improve color detection
  2. The latest version of the Sketch Map Tool leverages advanced Deep Learning models trained to analyze images of Sketch Maps and identify marked objects within them. Through supervised learning on extensive datasets of labeled images, these models acquire the ability to distinguish markings from the background of Sketch Maps by analyzing patterns and features. This enables them to accurately detect and differentiate markings. This predictive capability allows the models to generalize their understanding and accurately identify markings in new and unseen Sketch Maps. The Sketch Map Tool also incorporates conventional Computer Vision techniques to precisely position the Sketch Map within real-world coordinates. Georeferencing images entails detecting and matching specific points, such as the globes one the sketch maps, between the reference and current input image, enabling precise spatial alignment. Our current algorithm detects all markings, whether they are intended as a line, a point or a polygon as a polygon.

    Please make sure not to accidentally mark the globes on the edge as they are used for georeferencing purposes in order to ensure the automatic map detection.

    At the moment the Sketch Map Tool detects red, blue, green and black markings best, orange and yellow also work quite well. If different colors are used for specific topics, participants can include a legend for the meaning of each color outside the map extent. However, the tool does not support the identification of the written information or the matching of meanings to specific colors. This needs to be done manually in the subsequent analysis process in your Geographic Information System software. The GeoTiff can be used to manually match the geodata layer files to the legend information.

    The photo of the Sketch Map The result of the Color detection (the geojson)

    Image of a Sketch Map marked with red/blue polygons.

    Picture of a Sketch Map.

    Closed circles are detected as one polygon and the whole area will be detected/filled by the software.

    Result of Marking Detection.

    Image of a Sketch Map marked with different shapes.

    Picture of a Sketch Map.

    The shape of everything you write or draw on the map with a colour that the tool recognizes can be detected as a marked area (polygon). However, in some cases, they may not be detected at all.

    Result of Marking Detection.
    Recommendations:
    To Do Not recommended
    You will likely discover problems in the color- detected results

    Use thick felt-tip pens with intense colors.

    Picture of a Sketch Map.

    Thin lines in light colors might not be detected. If you decide to use additional colors, test which colors work best with the SMT before the mapping activity.

    Picture of a Sketch Map.

    For polygons, draw their outline as a closed, strong, and continues shape. You do not need to fill the polygons, and the pattern you draw in the middle will not be detected. In general, smaller polygons are detected better than large polygons.

    Picture of a Sketch Map.

    Gaps in the outline could lead to mistakes in the detection.

    Picture of a Sketch Map.

    Large polygons might not be detected properly.

    Picture of a Sketch Map.

    If you just draw a line, the marked area of the line will be detected. Nevertheless, we recommend not using lines so far, as this could lead to mistakes in the marking detection.

    Picture of a Sketch Map.

    If you want to draw a point, draw a larger circle or other shape, such as a cross or square in order to be detected well. If you want to draw lines, draw simple, non-dashed, and bright enough lines.

    Hint: If you need the marking as a line or a point shape, you can easily transfer it manually or digitalize it yourself, for example, in QGIS (see Training Exercise 4 )

    Satellite Base maps:

    Check the darkness of the Satellite base map, especially before printing it in black-and-white.

    Make sure you use bright colors and mark the maps especially clearly. Sometimes it might be helpful to use both Sketch maps with satellite images and OSM base maps for the mapping.

    Small polygons can be especially difficult to detected.

    Picture of a Sketch Map.
  3. Tips for better comparability and interpretation of the maps
  4. Map Orientation

    Orientating on a map can be challenging, depending on the base map, the background of the participants, and their map literacy. Mapping in groups can make orientation much easier, as participants can assist each other in reading the map. Before you start with the mapping, we recommend:

    • Start by identifying a common place or points of reference.
    • Try to locate the current position or the place of residence of the participant on the map.

    If you like to learn more about the challenges of map orientation and how to choose a good base map, take a look at Training Exercise 2. In Training Exercise 3,you can try mapping in groups in a role play.

    Develop a mapping strategy

    Prepare a clear data collection and analysis strategy beforehand. A consistent drawing/marking approach in different groups or by different people makes the comparison and analysis process easier since the data was collected in a similar way, and you know what it means. For this, you should discuss and agree beforehand:

    • What do you want to map?
    • Which colors should be used? For example, with blue, we map the area with the highest flood risk, and with red, we map safe places.

    You should test your mapping strategy beforehand: Print out a map, draw some test objects with the pens you are planning to use. Upload the map and check if the result is satisfactory.You can practice the development of a mapping strategy in Training Exercise 3.

    Organize your maps

    • Put a title on your map and add information about the participants, place and time to analyze the maps afterwards. Be careful; everything you write/draw on the map could be detected as a marked area (polygon), so use the white space outside the map extent.
    • If you collect additional information from the participants with other data collection methods such as Kobo Collect or ODK, add a number on the Sketch Map and save this number in the data collection questionnaire.
    • If you have many participants or you want participants to provide a lot of different information, it is recommended to use individual Sketch Maps for each purpose/topic or per participant.
2
Paper to GIS: Automatically digitize collected data
2.1 Scan or photograph your marked Sketch Maps

After the field data collection, scan or photograph the marked Sketch Maps.

Can be digitized properly Problem: Missing or cut QR-Code
Without the whole QR-code the map cannot be recognized by the Sketch Map Tool.
Problem: Missing Globs and missing part of the map
This could lead to mistakes in the georeferencing and missing information on your map..
Problem: Tilted photos of the map
Can lead to mistakes in the georeferencing.
Picture of a Sketch Map.
Sketch Map, No QR Code
Sketch Map, Cutted QR Code.
Sketch Map, Missing Globes.
Sketch Map, Tiled Picture.

Recommendations:
Picture of a Sketch Map.
  • The photos must be taken from directly above, at a 180-degree angle (parallel to the Sketch Map), for optimal image quality.
  • Pay attention to the lighting conditions when taking a picture.
  • The image of the Sketch Map needs to be uploaded as JPG or PNG (max. file size is 50 MB). The georeferencing and color-detection work even better if you scan the marked Sketch Map with a resolution of 300 dpi. Attention! The file size will be too large when scanning with a 600 dpi resolution.
  • If the color detection does not work satisfactorily, you can improve the color contrast of the markings (with a pen, a new photo, or with photo editing software such as Paint, GIMP, or Windows Cut & Resize).
2.2 Upload your Sketch Maps
Screenshot: Upload of a Sketch Map.

To upload files, you can click on the upload field or drag and drop your files directly into the upload field and then click on the Upload button. You can upload one or more marked Sketch Maps at once. However, they all must be the same base map (same QR-Code) , and all maps will be automatically combined in one Geojson in the download files for each color and Sketch Map. The upload works for JPG or PNG files. It is possible to upload more than one Sketch Map at the same time, but the upload will take longer. For one Sketch Map, it can take up to 100 seconds to produce a result, and for a package of 10 Sketch Maps, it can take up to 16 minutes.

Recommendations:
  • If you experience problems during the upload process, please check out the FAQ section below or contact your Sketch Map Tool focal point in your organization or the Sketch Map Tool user support
2.3 Download detected Markings as Geodata

Download the markings of the Sketch Maps in different geodata formats (raster data as GeoTIFF, vector data as a GeoJSON file). You can download the georeferenced Sketch Maps as a GeoTIFF or the color-detected markings as vector data in a GeoJSON file. The vector data output file consists of different layers for each color and Sketch Map, if you have uploaded more than one Sketch Map at once. The GeoTIFF output file consists of a georeferenced picture for each of your uploaded Sketch Maps. The GeoJSON file (vector file) consists of the color-detected markings from your Sketch Map as a vector layer.

Recommendations:
  • If you experience problems during the download process, please check out the FAQ section below or contact your Sketch Map Tool focal point in your organization or the Sketch Map Tool user support if you cannot find your answers there.
FINALLY: Import Geodata in a Geographic Information System (GIS), e.g. QGIS

The gained geodata can be even more valuable for the communities and humanitarian organizations if you create result maps or analyze it further. There are many different analyses possible based on your gained map data. If you would like more tips on different steps for basic analysis and how to create a result map, take a look at the following QGIS Training Lectures.

You can load your resulting geodata files into your GIS software.

GeoTiff GeoJSON

The GeoTIFF output file consists of a georeferenced "picture" for each of your uploaded Sketch Maps. When you open the GeoTIFF files in QGIS, it should look similar to this example and show all the markings on your sketch map(s) as separate layers. You can view only one of your maps at a time.

GeoTiff in QGIS.

If you open the GeoJSON, you can see the detected markings from all uploaded maps as polygons. When you check the attribute table, you can see that for each marking, the name of the map and the detected color are specified. With the help of these attributes, you can style your map or conduct analyses.

GeoJSON in QGIS.
GEOJSON in QGIS.
Recommendations:
  • Usage of the GeoTIFF file (raster file) in QGIS:
    • It can be used, for example, as a background to combine it with other data or to manually digitize your results yourself in case some markings are not detected correctly.
  • Usage of the GeoJSON file (vector file) in QGIS:
    • You can compare the vector output with the raster file to verify the marking detection. In case features are not detected or are incorrectly detected, you can manipulate your vector file based on the GeoTIFF.
    • It can be visualized in a clear and concise map in order to use it for reporting (see Training Exercise 4)
    • Based on the vector outputs you can analyze your data and combine it with additional data (e.g. prepare heatmaps, see Training Exercise 5 )
  • If the imported data looks strange and does not represent the actual markings of the sketch maps, please check your uploaded sketch map files and, if necessary, scan them again or take new pictures. Please review the recommendations in the sections about the data collection, then scan, photograph or the upload above and consult our FAQ section about the problems in the colour detection. If you cannot find your answers there, please contact your Sketch Map Tool focal point in your organization or the Sketch Map Tool or the Sketch Map Tool user support.

FAQs

What are OSM data?
OpenStreetMap data is freely accessible geodata. You can find out more about it here.
What are the quality levels for OSM data used in the tool?
The OSM data is classified with a traffic light system. Green stands for good suitability of the data, yellow for possible problems when carrying out a Sketch Map study with OSM-based Sketch Maps, and red for probable problems. Recommendations are also given on what to consider based on the results.
Which analyses are performed and why?
You can read more about the analyses included in the Sketch Map Tool this paper.
Why is it important to analyze the suitability of OSM data before creating a Sketch Map
OSM data is used for the creation of the Sketch Map. If the OSM data in a study area lack some important features, they are missing on the maps as well. Thus, the quality of the OSM data is directly related to the quality of the Sketch Maps. The features might be relevant for participants to orientate on the map.
For which research questions can the Sketch Map Tool be used?
The Sketch Map Tool has been primarily developed for research questions related to floodings. Since then, it has been used world wide for a variety of topics like vulnerability and capacity mapping or risk mapping in general. You can use the Sketch Maps and the Map Quality Check to investigate all kinds of research questions, as long as you check that it fits your purpose.
How does mapping work with the Sketch Map Tool?
The local population can, for example, draw flooded areas such as streets, parks, etc., on the printed Sketch Map. The larger paper formats also allow to hold group discussions about flooded areas. The maps with the markings can be photographed and uploaded to the tool. The georeferenced TIFF and shape files can then be further analyzed or used.
How large can my study area be?
So far the Sketch Map Tool has only been tested on neighborhood or city level. The tool works best for study areas which are smaller than 50kmĀ².
Why are there a QR code and globes on the Sketch Maps?
These are required for georeferencing. This is why it is important to have them on the Sketch Maps.
Can I access my results at a later point in time?
No, the results should always be downloaded directly after using the tool. If you forgot to download the files, you can simply upload and process the files again.
What do I have to pay attention to in the field?
Please make sure not to accidentally mark the globes at the edge as they are needed to improve the automatic map detection. But if someone accidentally marked the globes, it might still be possible to upload the Sketch Maps. Try the automatic detection of the map boundaries. Use thicker felt-tip pens with intense colors; red, blue, and black work best. Prepare the same set of pens for all interviewers. Add a number on the Sketch Map and save this number in the questionnaire as well, if you use one.
How does the georeferencing work?
How can I ensure optimal results when photographing the Sketch Maps?
The images need to be in JPG or PNG format. The file may not be larger than 500  MB. Georeferencing works best if you scan the marked Sketch Map with a resolution of 300 dpi. The photos must be taken from above at a 180 degree angle (parallel above the Sketch Map) to produce the best result.
How do I check if georeferencing is correct?
You can open the TIFF file in a geographic information system (GIS), such as ArcGIS or QGIS, to check this. If you upload the file there and insert a basemap (for example the OSM basemap), you can see if georeferencing has worked. The Sketch Map should match the base map.
Why does my generated TIFF file look strange?
Please first try to open the file in a geographic information system (GIS) such as ArcGIS or QGIS. The georeferencing may have worked even if the TIFF file does not look right. If it still appears incorrect in the GIS, the map might not have been properly detected by the tool in the photo, and there could be various possible reasons. For example, the photo may have been taken from the wrong angle or the globes may have been painted over.
What can I do if the satellite map I printed is too dark?
In case you use a satellite imagery background, please review the color saturation of your image. If the background is too dark, you might consider to choose OSM as base map.