Browsing by Author "Dugan, Hilary"

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    GLADD-R: A new Global Lake Dynamics Database for Reservoirs created using machine learning and satellite data
    (2019-04-01) Khandelwal, Ankush; Karpatne, Anuj; Wei, Zhihao; Kuang, Huangying; Ghosh, Rahul; Dugan, Hilary; Hanson, Paul; Kumar, Vipin
    Reservoirs play a crucial role for human sustenance as they provide freshwater for agriculture, power generation, human consumption, and recreation. A global database of reservoirs that provides their location and dynamics can be of great importance to the ecological community as it enables the study of the impact of human actions and climate change on fresh water availability. Here we present a new database, GLADD-R (Global Lake Dynamics Database-Reservoirs) that provides such information for 1882 reservoirs between 1 and 100 square kilometers in size that were created after 1985. The visualization of these reservoirs and their surface area time series is available at http://umnlcc.cs.umn.edu/GlobalReservoirDatabase/.
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    ReaLSAT: A new Reservoir and Lake Surface Area Timeseries Dataset created using machine learning and satellite imagery
    (2020-08-04) Khandelwal, Ankush; Ghosh, Rahul; Wei, Zhihao; Kuang, Huangying; Dugan, Hilary; Hanson, Paul; Karpatne, Anuj; Kumar, Vipin
    Lakes and reservoirs, as most humans experience and use them, are dynamic three-dimensional bodies of water, with surface levels that rise and fall with seasonal precipitation patterns, long-term changes in climate, and human management decisions. A global dataset that provides the location and dynamics of water bodies can be of great importance to the ecological community as it enables the study of the impact of human actions and climate change on fresh water availability. This paper presents a new database, ReaLSAT (Reservoir and Lake Surface Area Timeseries) that has been created by analyzing spectral data from Earth Observation (EO) Satellites using novel machine learning (ML) techniques. These ML techniques can construct highly accurate surface area extents of water bodies at regular intervals despite the challenges arising from heterogeneity and missing or poor quality spectral data. The ReaLSAT dataset provides information for 669107 lakes and reservoirs between 0.1 and 100 square kilometers in size. The visualization of these water bodies and their surface area time series is also available online. The aim of this paper is to provide an overview of the dataset and a summary of some of the key insights that can be derived from the dataset.
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    The Story of Nitrogen Episode 5- A Legacy of Salts
    (2021-11-22) Klinger, Greg; Bugeja, Shane; Dugan, Hilary; Strock, Jeff; Castellano, Mike; Barry, John
    If you want to understand how nitrogen behaves in the soil, it pays to think about two things: water and time. These two factors control when and how much nitrogen can be lost from soil. They also help explain why some landscapes accumulate the nitrate form of nitrogen while others do not. Join us as we discuss how nitrogen moves through soils, how we can control its losses, and the surprising connections between nitrate, road salt, and nuclear testing. Related content: Nitrate removal from water (https://www.youtube.com/watch?v=Z0kiYmKShsw); How does water (and things like nitrate) move through bedrock? (https://www.mda.state.mn.us/segwresources#Videos); Great video on water movement through soils (https://www.youtube.com/watch?v=0GgCwmAYj5s). To learn more: Chloride in freshwater lakes (https://www.pnas.org/content/114/17/4453.full/); Integrating water management practices to remove nitrate (https://www.youtube.com/watch?v=jbm2uemjBPE&t=3s); Wetlands, bioreactors and other ways to remove nitrate from water (https://www.youtube.com/watch?v=1-irSjH2e1w); Groundwater flow in southeastern Minnesota (https://conservancy.umn.edu/handle/11299/162612).