Post-update OSM data report#

This project focused on mapping and improving buildings and roads in 22 refugee camps in Chad. Additionally, water bodies like rivers and streams were included where they occured; but in less quantity since these features were not found in all the camps.

The mapping was done following good practices of OSM mapping, mainly during the validation and improvement of the existing data on the map added by other mappers from the OSM community.

Mapping Tools:#

  • OpenStreetMap: A collaborative project to create free and editable maps. All the data were updated directly here.

  • JOSM: The OpenStreetMap editor used by the data team to do edits easier and faster.

  • Tasking Manager: OSM management tool to avoid conflicts during the mapping process.

_images/post_update_chad_camp_1.gif

Fig. 42 Mapping workflow with JOSM editor and a Tasking Manager#

Validating existing OSM data#

Previous to the mapping process we found data added by other mappers from the OSM community and most of this data was added trough projects from Humanitarian OpenStreetMap Team.

Some of these data had good quality but in most of the camps data had to be improved to align to the most current imagery and improve the building and road shapes.

_images/post_update_chad_camp_2.png

Fig. 43 Baseline Data#

_images/post_update_chad_camp_3.png

Fig. 44 Data after updating#

Although the team relied on the most current imagery basemap (Maxar premium), data were found that did not match with any satellite imagery and according to the source attributes, they were added by local knowledge. These data were not changed and were left as they were found.

_images/post_update_chad_camp_4.png

Fig. 45 Buildings and highways added by local knowledge#

Mapping of camps without data#

There were camps that did not have any data or the coverage of the existing data was very low. On those camps, We added all the buildings and all types of roads visible on the satellite imagery.

_images/post_update_chad_camp_5.gif

Fig. 46 Comparison of the Pre-update data VS Post-update data in Treguine Camp#

Challenges in the mapping#

The main difficulty during the mapping was the low quality of the baseline satellite imagery, which was more notable in some camps where the density of the buildings was high or in areas with a lot of trees.

_images/post_update_chad_camp_6.png

Fig. 47 Maxar imagery with trees#

_images/post_update_chad_camp_7.png

Fig. 48 Bing imagery#

Post-update stats#

At the end of the mapping, the data team completed the mapping of 21 of 22 camps. The table contains the final stats of buildings and roads added/improved per camp.

N°

Camps

Most current imagery

Total buildings

Total highway Length

OSM link

Baseline

After mapping

Baseline

After mapping

01

Amboko Camp

Maxar Premium

1,813

3,368

8.051 km

14.326 km

https://www.openstreetmap.org/way/197262638

02

Amnabak

Maxar Premium

398

6,896

1.472 km

50.837 km

https://www.openstreetmap.org/way/462577820

03

Belom

Maxar Premium

4,450

9,598

27.338 km

70.768 km

https://www.openstreetmap.org/way/229227293

04

Bredjing Camp

Maxar Premium

34

11,195

14.743 km

34.452 km

https://www.openstreetmap.org/way/462543665

05

Daha 1 Village

Bing Aerial

222

1,821

6.035 km

25.328 km

https://www.openstreetmap.org/way/618226171
https://www.openstreetmap.org/way/606743679

06

Dembo

Maxar Premium

2,324

3,701

41.02 km

34.722 km

https://www.openstreetmap.org/way/597226998

07

Diba Village

Maxar Premium

0

468

0.455 km

3.792 km

https://www.openstreetmap.org/way/594095129

08

Djabal Camp

Maxar Premium

4,884

9,259

49.163 km

56.947 km

https://www.openstreetmap.org/way/881919013

09

Doholo Camp

Maxar Premium

2,037

2,218

3.314 km

45.76 km

https://www.openstreetmap.org/way/755468804

10

Dosseye Camp

Maxar Premium

1,503

4,781

36.14 km

81.961 km

https://www.openstreetmap.org/way/345244949

11

Farchana

Maxar Premium

7

7,524

37.94 km

54.718 km

https://www.openstreetmap.org/way/251885724

12

Gaga Camp

Maxar Premium

18

11,647

13.735 km

67.895 km

https://www.openstreetmap.org/way/462564704

13

Gondje Camp

Maxar Premium

1,168

2,273

38.339 km

43.807 km

https://www.openstreetmap.org/way/883703067

14

Goz Amir Camp

Maxar Premium

133

22,318

25.83 km

138.422 km

https://www.openstreetmap.org/way/199347779

15

Iridimi

Maxar Premium

8,213

12,486

20.555 km

64.854 km

https://www.openstreetmap.org/way/198678903
(This camp includes different boundaries. One of them is the above boundary.)

16

Kounoungou Camp

Maxar Premium

34

7,078

7.95 km

40.216 km

https://www.openstreetmap.org/way/462573532

17

Mile Camp

Maxar Premium

5,343

6,910

21.314 km

57.652 km

https://www.openstreetmap.org/way/462585747

18

Moyo

Maxar Premium

7

1,627

0.0 km

33.172 km

https://www.openstreetmap.org/way/213159627

19

Oure Cassoni Camp

Maxar Premium

8,623

20,245

37.673 km

80.44 km

https://www.openstreetmap.org/way/198231230

20

Touloum

Maxar Premium

7,832

9,672

53.97 km

92.742 km

https://www.openstreetmap.org/way/462580702

21

Treguine Camp

Maxar Premium

0

11,962

19.522 km

42.235 km

https://www.openstreetmap.org/way/462543655

22

Vom village

Maxar Premium

0

1,275

1.909 km

9.251 km

https://www.openstreetmap.org/way/594095131

Since We completed the hours of the project, We were unable to map and validate the data of “Kounoungou Camp”, however, this was mapped by the community and now it presents more data compared to what was found in the pre-update report.