The October 2014 issue of GIS Professional features a three-page article on the work we have been undertaking using Unmanned Aerial Vehicles (UAVs). Written by Sandy Avery and Bruce Gittings, and based on Sandy’s GIS Masters dissertation, the article explores the use of a low-cost quadcopter platform – the DJI Phantom described in earlier blog posts – with comparisons of GoPro and Canon SX230 cameras. The article outlines our experiences flying over the summer and explains the procedures we have developed for safe and successful operation. The cover image shows the Phantom silhouetted against a dark Edinburgh sky while examining tree canopies. The article concludes that the Phantom is a serious tool for aerial survey and low-cost photogrammetry, with the 12 megapixel Canon camera proving rather more capable than the GoPro which is more usually used.
Professor Iain H. Woodhouse has made mapping the world’s forest one of his primary goals, in both research and practice. He co-founded Carbomap Ltd. in 2013 in order to apply his knowledge of mapping carbon from forests, and contributes to Ecometrica, helping businesses to become more environmentally conscious. He works in Malawi with REDD Horizon to help keep the forests sustainable for both the environment and the people who rely on them. And of course, as a professor he teaches and works with students, passing his knowledge along to the next set of environmentally conscious individuals.
His talk on Friday 26th September, entitled “Mapping the world’s forests, long ways and short ways” highlighted the issues centric to mapping the carbon in the world’s forests. Deforestation is not the problem of a single country even though it may take place in one, but a global issue, as changes in one area can affect not only that region, but people around the world. Forests are a key factor in the carbon cycle, and because they cover approximately 30% of all land area on earth, any change in the amount of land area covered can have drastic effects. The problem, however, is how to tackle the problem, and Professor Woodhouse has narrowed it down to three main criteria: global, timely, and detail.
Economies and personal use drive deforestation at an individual and global scale, making it an issue that spans country and political boundaries, and yet there is a disconnect between science and policy: Malawi’s carbon loss is negligible on a global scale, but small changes in the amount could be disastrous for individuals relying on the forests within the country. What works for one country may not work for another, or even for the global problem as a whole.
Timeliness of data collection can influence political decisions either too late or not enough—such as getting to illegal loggers fast enough—due to the number of satellites and regular coverage of an area. The data is difficult to process even when the clouds and canopy height are not affecting the quality of the data collected. Data quality is also affected by the detail of the data, and while the saying is “the Devil’s in the details,” in the case of global deforestation, too much data can be a hindrance rather than help. Detail at a local or national level is ideal, but too much on a dataset covering large sections of the Earth does not work well.
Perhaps the biggest issue in regards to deforestation, and one that covers all three main criteria in one, is that of control. Who has control of the data? Is it researchers in the United States, for example, giving the data to countries that need it, or is it people on the ground who then have to deliver the data elsewhere? How much lag time is there between data gathering and processing to the delivery of the data to the people who need it? Are the people who requested the data capable of processing or using it once they can get it?
Besides these questions, there is a matter of what system to use. Since no one way or method can solve all the problems involved with gathering and using data related to deforestation, there is no single software or data type that will give all the answers. Optical satellites and UAV LiDAR both work well, but cannot be used for the same thing. In the end, a multi-scale system—one that allows each country to decide cost and runtime, as well as control their data—is the only definite answer, but even that is not very specific, because every country is unique in their data needs.
While vampires are slain with a stake to the heart, faeries are kept away with iron, and are werewolves taken down with a silver bullet, deforestation is not an easy or simple thing to fix, and so researchers like Professor Iain H. Woodhouse continue their quest to find the best way (or ways) to slay their dragon.
(MSc in GIS at the University of Edinburgh)