Seven maps that explain logging in the Solomon Islands

A couple of weeks ago, Global Witness released a major report on how the logging industry is running amok in the Solomon Islands. In ten years, almost every island’s rainforest has seen extensive logging with much of the timber destined for China. Using MapHubs, OpenStreetMap, and satellite imagery, we helped Global Witness map, quantify, and document the impact logging has had across the Solomons. Here are seven maps that explain how we did it. Click on the play buttons to view the interactive maps.

Maps 1 and 2 - Mapping Logging Roads in OpenStreetMap

(Map Link)

(Map link)

At over 12,600 kilometers, there are more logging roads in Solomon Islands than in all of downtown Beijing. Because trees are never far from transport via the sea, small islands are particularly vulnerable to rapid deforestation . This makes trees easy to locate, cut and export. To find roads, we used false color Landsat and Sentinel imagery and traced all roads that were not already in OpenStreetMap ( We filtered out residential, public and plantation roads and then generated a 1km buffer around each road and clipped the area to a coastline dataset from National Oceanic and Atmospheric Administration (NOAA). The road data was then exported to MapHubs and combined with other map layers.

Map 3 - Roads above 400 meters

(Map link)

This map shows logging roads that have strafed the flanks of Mount Veve, an extinct volcano, on Kolombangara Island. While Solomon Islands’ Forest Act tries to restricts logging below 400 meters, we mapped many roads above this altitude. We used elevation data from NASA to identify roads cut above 400 meters and used the University of Maryland’s Tree Cover Loss data to determine whether they are active. Global Witness estimates that one in every 20 km of logging road in the Solomon Islands is above 400 m in altitude, despite the fact that the Forest Act requires companies to apply for special permission to log there.

Map 4 - Area within 1km of a road

(Map link)

We found that an astonishing 53% of the Solomon Islands below 400 meters is within 1 km of a logging road. This means that most of the islands remaining forest is vulnerable to conversion.

Deforestation Analysis

Using the University of Maryland’s Tree Cover Loss data we calculated historical deforestation stats for the area with 1km of a road. This analysis shows an upward trend in deforestation that coincides with the increase in exports reported by Global Witness.

Maps 5 and 6 - Documenting the impacts

Choiseul 1

Guadacanal 1

These two animations show logging impacts on the rainforest. We used high resolution satellite imagery from DigitalGlobe to create time sequence maps of the deforestation. MapHubs makes handling imagery simple. In the past, satellite scenes required downloading giant files and then processed them into heavy duty GIS software. With MapHubs, we built integration with DigitalGlobe’s API, so once you find the scene that you want, you can load it into your MapHubs platform, combine it with your maps layers, and make an interactive map. This is particularly handy for deforestation monitoring as stakeholders usually want to see time stamped imagery to prove that forest was indeed lost.

Map 7 - Coordinating field work

While road data, deforestation alerts, and satellite imagery builds a evidence of deforestation, field work is still necessary to verify information. To help coordinate field data collection, we made maps and coordinates of logging locations on various Solomon Islands. A field investigator used these maps to capture drone footage of these locations. This provided both evidence of the impact on the ground and strong visuals to communicate the issue to stakeholders and the public.

Protecting Solomon Islands’ rainforest is Possible!

These maps demonstrate that with affordable mapping technology like MapHubs and OpenStreetMap, a small dedicated team can bring transparency to whole industry across a country. Effective forest monitoring does not require multi-million dollar websites and expensive satellite imagery. the Solomon Islands is an impoverished country without a well resourced forestry department. Despite these limitations, Countries like the Solomons can begin getting to grips with logging and other emerging threats to forest by using simple but effective tools to monitor rainforest and enforce the rule of law.