Seite - 6 - in options, Band summer 2015

research news 6 options + summer 2015 www.iiasa.ac.at iiasa research Connecting the dots Understanding patterns in distributions of  localized entities as diverse as humans, trees, animals, houses, firms, factories, crimes, etc., is an important challenge for spatial statistics. Until now, key methods have focused on the spatial relationships between pairs of locations. In a new study, IIASA researchers have introduced new methods for analyzing triangles of locations. The resultant third‑order statistics can reveal patterns not captured  by the traditional range of  second‑order statistics. Sustainability and the land–water–food nexus A new IIASA study, presented at the International Soil Week conference in  April, examines the economic links, co‑benefits, and trade‑offs between the  different aims of the proposed Sustainable  Development Goals, particularly between land, food, and water  resources. Conservation efforts focused on a single resource or region can  drive prices up, leading to food insecurity and even greater exploitation of  other resources, the study found. www.iiasa.ac.at/news/esm-sdg-15 Longer life—slower aging? Faster increases in life expectancy do not necessarily produce faster population aging, according to new IIASA  research published in the journal PLoS  ONE. In fact, according to researchers Warren Sanderson and Sergei Scherbov, when  new measures of aging are taken into account, the opposite is true. Read more on page 12. www.iiasa.ac.at/news/aging-life-15 Education and vulnerability Education makes people less vulnerable to  natural disasters such as floods, landslides, and storms that are expected to  intensify with climate change, according to a new study from IIASA population researchers. In  a paper published in Science, Wolfgang Lutz, Raya  Muttarak, and Erich Striessnig show  that in many cases, educational expansion could be a better investment for  climate adaptation than conventional investments in infrastructure. Read more on page 14. www.iiasa.ac.at/news/pop-edu-14 Citizen science boosts global  mapping efforts Hundreds of satellites orbit our planet, like bumblebees buzzing around a flowering apple tree. While many of these satellites link global communications networks, a number are dedicated to scientific studies of the Earth, measuring the planet’s surface and atmosphere. Yet even with all the satellite data about the Earth’s surface, maps of the planet’s land cover—forests, grasslands, farms, waterways, and cities—still suffer from disagreement between sources and missing information. We don’t know where all the Earth’s forests are, nor do we know where and how much cropland is being farmed. Yet these data are vital for understanding global issues like climate change and food security. IIASA’s Geo-Wiki team takes a unique approach to global land-cover mapping, combining and comparing multiple satellite data products, and relying on the most innovative and creative computing system in existence—the human brain—to check their work and train  the model. This spring, the team has published new global maps of forest and cropland, which combine remote sensing data from multiple sources, including input from the Geo-Wiki  citizen science network. Both maps are a leap forward compared to existing data products. The cropland maps, for instance, use comparisons between satellite data products to determine the likelihood that cropland exists in a given place. The cropland maps also include the first-ever map  of field size based on crowdsourced data. The researchers used the same methods to produce their new map of global forest cover, which was published this spring, the first to be consistent with statistics of the Food  and  Agriculture Organization. IIASA researcher Dmitry Schepaschenko, of the Geo-Wiki team, says, “By combining different data sources, and incorporating the input of trained citizen scientists, we were able to produce new maps that are more accurate than any existing data source.” All the maps are available for exploration and download at www.geo-wiki.org. KL Further info Schepaschenko D, See L, Lesiv M, McCallum I, Fritz S, Salk C, Moltchanova E, Perger  C, Shvidenko A, Albrecht F, Kraxner F, Dürauer M, Obersteiner M, et al (2015). Development  of a global  hybrid forest mask through the synergy of remote sensing, crowdsourcing and  FAO statistics. Remote  Sensing of Environment 162:208–220 [doi:10.1016/j.rse.2015.02.011]. § Fritz  S, See L, McCallum  I, Bun  A, Moltchanova  E, Duerauer M, Perger C, Havlik P, Mosnier A, Schepaschenko  D, van  der  Velde  M, Dunwoody  A, Kraxner  F, Obersteiner M, et al (2015). Mapping global cropland field size. Global  Change Biology 21(5):1980–1992 [doi:10.1111/gcb.12838]. Steffen Fritz fritz@iiasa.ac.at