Access to Online Historical Aerial Photography Collections: Past Practice, Present State, and Future Opportunities

Abstract

The authors review how access to historical aerial photograph collections has evolved in response to technological developments and addresses areas for further advancement, with a particular emphasis on developing, preserving, and sustaining online collections. The authors focus specifically on the areas of metadata, the Semantic Web and linked data, and sustainability through collaboration. The article includes brief case studies, highlighting various projects involving the aerial photography collections at the University of Minnesota. The conclusion asserts the critical role played by geographic information librarians in effectively carrying out the strategies described in the article as they relate to the long-term sustainability of digital geospatial collections.

Century-scale wood nitrogen isotope trajectories from an oak savanna with variable fire frequencies

“…For each tree, % N increased consistently through the last sample, and the last two to three samples exhibited markedly higher % N than in previous years. This result is consistent with the well-documented pattern of increasing wood % N after the heartwood-sapwood transition with the highest values in the most recent rings (Poulson et al, 1995;McLauchlan and Craine, 2012). Wood % N was negatively correlated with wood δ 15 N across all trees (r = −0.38; p<0.001).…”

“…Post-fire nitrification is another mechanism that could affect soil and wood δ 15 N, causing increased δ 15 N values of NH + 4 and decreased δ 15 N values of NO − 3 (Högberg, 1997). This mechanism could affect wood δ 15 N at this site, as there is evidence that Quercus seedlings show a greater rel-ative preference for NO − 3 over NH + 4 (Templer and Dawson, 2004), and preferences for inorganic N were reflected in Q. alba wood δ 15 N in an Indiana hardwood forest (McLauchlan and Craine, 2012). Soil net nitrification was negatively related to fire frequency across the CCESR burn experiment (Reich et al, 2001), but our wood δ 15 N data cannot address the extent to which nitrification is altering the supply of available N. Beghin et al (2011) invoked both litter combustion and post-fire nitrification in their study of long-term N cycling in a pine forest.…”

Online digital archive of aerial photographs (1935–1941) of Ethiopia

“…There are few publications concerning digital archives of historical aerial photographs, mostly regarding the USA, particularly California in 1938 (Ma, 2013), Illinois in the 1930s (Luman et al ., 1997), the Everglades in the 1920s (Smith et al ., 2010) or the overall USA (McAuliffe et al ., 2017), and rarely from Europe such as Wales (Wilson et al ., 2016). Very few stress the need for user‐friendly digital archives or online interface (Caswell, 2012; Long et al ., 2005; Mathews, 2005).…”

Advancing the historical geography of late Ottoman and British Mandate Palestine using GIScience: A review

“…An expert estimation assumes thousands of relevant visual sources, but this is only a rough figure 3 . Fortunately, as the online storage and web capabilities develop, more visual sources become accessible for download and usage through advanced online metadata search (McAuliffe, Lage, & Mattke, 2017). Naturally, the foremost archives are the national archives.…”