Hydrological Greenroof Modeling Program using water balance methods applied to the analysis and design of a greenroof.

摘要

The Hydrological Greenroof Modeling Program is a Microsoft Excel 2010 based program that models a typical greenroof with inputs including soil type, soil depth, retention mat layers, vegetation type, and weather data. It was developed to calculate hourly runoff, interception, and soil retention values for any greenroof. The Hydrological Greenroof Modeling Program was applied to data from four different data sets including the 1988, 2001, and 2011 JFK weather data as well as the January, February, and March 2013 JASA rooftop weather data collected using monitoring equipment installed on the JASA rooftop.;The proposed JASA greenroof design consisted of a 4-inch soil depth with a 0.5-inch water retention mat and grass vegetation planted above the soil. The water holding capacity of the 4-inch soil depth was 0.40 inches and the water holding capacity of the 0.5 inch retention mat was 0.08 inches, with a total water holding capacity of 0.48-inches. The Hydrological Greenroof Modeling Program calculates interception capability of the JASA greenroof using MORECS 2.0 leaf area index calculated interception values for grass. The Hydrological Greenroof Modeling Program calculates runoff from the JASA greenroof by means of a 1-inch Parshall Flume and by empirical methods of subtracting the calculated interception and retention values from the precipitation.;The calculated results had an average of 42.40% runoff, 8.74% interception loss, and 52.84% soil retention over all four data sets including 1988, 2001, 2011, and Jan., Feb., and March 2013. The average calculated percentage of precipitation that was diverted from the sewer was 61.58% of the total precipitation for the proposed JASA greenroof.