Browsing by Subject "rainfall"

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    Exploring Spatial Optimization Techniques for the Placement of Flow Monitors Utilized in RDII Studies
    (2010-08-31T14:31:55Z) Skehan, Christopher A.; Banerjee, Aniruddha; Johnson, Daniel P. (Daniel Patrick), 1971-; Wilson, Jeffrey S. (Jeffrey Scott), 1967-
    The aging infrastructure of a wastewater collection system can leak, capture ground water, and capture precipitation runoff. These are some of the most common problems in many of today’s US collection systems and are often collectively referred to as Rain Derived Inflow and Infiltration (RDII or I/I). The goal of this study is to investigate such optimized methods and their potential to improve flow monitor placement, especially for RDII studies, and to improve upon Stevens (2005) methodology. This project adopts a methodology from the “facility location problem”, a branch of operations research and graph theory. Solutions to a facility location problem will be adapted and utilized within a transportation GIS application to determine optimal placement.
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    Stable isotope compositions (δ2H, δ18O and δ17O) of rainfall and snowfall in the central United States
    (Nature Publishing group, 2018-04-30) Tian, Chao; Wang, Lixin; Kaseke, Kudzai Farai; Bird, Broxton W.; Earth Science, School of Science
    Stable isotopes of hydrogen and oxygen (δ2H, δ18O and δ17O) can be used as natural tracers to improve our understanding of hydrological and meteorological processes. Studies of precipitation isotopes, especially 17O-excess observations, are extremely limited in the mid-latitudes. To fill this knowledge gap, we measured δ2H, δ18O and δ17O of event-based precipitation samples collected from Indianapolis, Indiana, USA over two years and investigated the influence of meteorological factors on precipitation isotope variations. The results showed that the daily temperature played a major role in controlling the isotope variations. Precipitation experienced kinetic fractionation associated with evaporation at the moisture source in the spring and summer and for rainfall, while snowfall, as well as precipitation in the fall and winter, were mainly affected by equilibrium fractionation. The 17O-excess of both rainfall and snowfall were not affected by local meteorological factors over the whole study period. At the seasonal scale, it was the case only for the spring. Therefore, 17O-excess of rainfall, snowfall and the spring precipitation could be considered as tracers of evaporative conditions at the moisture source. This study provides a unique precipitation isotope dataset for mid-latitudes and provides a more mechanistic understanding of precipitation formation mechanisms in this region.