Environment: Satellite pictures that show how forest fires were started to clear land for farmers

Singapore's leading newspaper used these colour photos yesterday to make one simple point: "Indonesia's forest fires are no accident or act of nature," the daily Straits Times said.

The photos show that forests were being cleared to make way for plantations, with fire employed as the means of getting rid of the natural vegetation. They also show the fires continuing into September, by which time the smog had hit health-damaging levels.

The red areas are jungle; the green areas are clear plantation land. The artificial colouring makes it easier to see the pattern of events.

The main picture shows the area when the fires first started, with small puffs of smoke across the area demonstrating that the fires had multiple sources.

The second picture (above left) shows the fires raging, with smoke drifting across the area. The third picture shows that the burnt area has been cleared, and is being used as farmland.

The pictures, taken by the National University of Singapore (NUS) Centre for Remote Imaging Sensing and Processing, can pinpoint the fires to 10 or 20 metres. "By just looking at the photographs, Indonesian authorities should be able to tell who owns a piece of land which has been cleared by fire, or from which plumes of smoke rise," the Times said.