PLAN341 Lecture Notes - Lecture 16: Stormwater, Geomorphology, Viscosity
27 May 2016
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Document Summary
Distinguishing features of a wetland: presence of water at the surface or in the rooting zone, unique soil conditions, vegetation adapted or tolerant of wet conditions (or the absence of flood-intolerant species) Urban landscapes 80% of the population lives on 10% of the land. Hydrologic systems change in urban settings since water is collected rather than infiltrated. Relationship between impervious cover and volumetric runoff coefficient - as imperviousness increases, runoff volume also increases - directly correlated. Runoff coefficient expresses the fraction of rainfall that is converted into runoff. Groundwater table goes down b/c less infiltration. Event mean concentration (emc) - determines pollutant loads from a site; most representative of average pollutant concentrations over a runoff event, helps determine water quality load of sediment / amount of water = mean concentration. First flush phenomenon: initial surface runoff of a rainstorm. 2 critical time periods: t1, t2 bulk of water has been removed.
