Bodies of water. The Water Observatory “provides reliable and timely information about surface water levels of water bodies across the globe.” The locations are based on NASA’s Global Reservoir and Dam Database and the World Wildlife Fund’s Global Lakes and Wetlands Database. Concerned about the accuracy of the boundaries in those databases, the researchers instead treated them as a “collection of potentially interesting water bodies” and then “extracted their polygons from the OpenStreetMap.” Of the 40,000 bodies of water they extracted, they’ve published water level data for roughly 7,000 through the project’s interactive dashboard and API. [h/t Emma Vitz]
Hydro, streams, and rivers. As part of Oak Ridge National Laboratory’s efforts to evaluate America’s hydropower resources, researchers there have developed a system (and corresponding dataset) for classifying all 2.6 million streams in the Lower 48 by size, hydrology, gradient, temperature, and “valley confinement.” Elsewhere, other researchers have assessed the “connectivity status of 12 million kilometres of rivers globally” and have identified “those that remain free-flowing in their entire length”; you can download that data and also explore it online.
The height of the frozen world. ICESat-2, launched by NASA in September 2018, “is measuring the height of a changing Earth one laser pulse at a time, 10,000 laser pulses per second”; the satellite “allow[s] scientists to monitor the elevation of ice sheets, glaciers, sea ice, and more—all in unprecedented detail.” Its datasets are available to download. [h/t Michael McLaughlin]
Drought conditions. The Standardised Precipitation-Evapotranspiration Index is a metric, calculated from climatic data, that “can be used for determining the onset, duration and magnitude of drought conditions with respect to normal conditions.” The project, based at the Spanish National Research Council, provides both a “near real-time” global drought monitor and a historical database.
Welsh shipping crews. “The Merchant Shipping Act 1835 required all British registered ships of 80 tons or more employed in the coastal trade or fisheries to carry crew agreements and accounts, often referred to as crew lists.” The lists include crew members’ ages, places of birth, previous vessels, and more. Thanks to the National Library of Wales Volunteering Programme, thousands of crew lists from the Welsh port of Aberystwyth, from 1856 to 1914, have been transcribed. [h/t u/cavedave]