Green roof (GR) technique is one of the most effective solution to mitigate the increasing flood risk in urban areas caused by the uncontrolled soil sealing. The use of satellite images allows to identify in vulnerable area, the potential of existing buildings for green roof retrofitting according to four criteria that are roof slope, number of stories, orientation of the roof, number of site boundaries. The aim of the present work is to test the effectiveness of GRs at city scale in preventing the urban flooding events. The case study is Preturo municipality in Southern Italy. The site has been selected as part of Sarno river basin, a catchment that during the last two decades has been interested by several damaging flash floods. The analysis of land use change within Sarno watershed has been carried out using SAR images from ERS-1 and COSMO-SkyMed sensors. The results have suggested that the increase in the occurrence of extreme events matches with the expansion of urban area in the same period, reason why the application of GR technology could lead to a successful stormwater management. Indeed, the coherence estimation of SAR imagery, has detected a build-up area ranging from about 7% to about 12% between 1995 and 2016. An in-depth analysis has been performed moving from basin to city scale with the aim to test the ability of GRs to mitigate the urban flooding using SWMM. Satellite images available in Google Earth have been used to evaluate the suitability for green roof retrofit in Preturo municipality. According to building attributes for GR retrofit, a percentage of GR conversion of about of 7% has been detected resulting in a low attenuation of flooding volume. This finding suggests to couple the GR technology to other Low-Impact-Development practices in order to improve the stormwater reduction.
Using satellite imagery to detect land cover change and the suitability for green roof retrofit in Preturo municipality
mirka mobilia
;Antonia Longobardi
2021-01-01
Abstract
Green roof (GR) technique is one of the most effective solution to mitigate the increasing flood risk in urban areas caused by the uncontrolled soil sealing. The use of satellite images allows to identify in vulnerable area, the potential of existing buildings for green roof retrofitting according to four criteria that are roof slope, number of stories, orientation of the roof, number of site boundaries. The aim of the present work is to test the effectiveness of GRs at city scale in preventing the urban flooding events. The case study is Preturo municipality in Southern Italy. The site has been selected as part of Sarno river basin, a catchment that during the last two decades has been interested by several damaging flash floods. The analysis of land use change within Sarno watershed has been carried out using SAR images from ERS-1 and COSMO-SkyMed sensors. The results have suggested that the increase in the occurrence of extreme events matches with the expansion of urban area in the same period, reason why the application of GR technology could lead to a successful stormwater management. Indeed, the coherence estimation of SAR imagery, has detected a build-up area ranging from about 7% to about 12% between 1995 and 2016. An in-depth analysis has been performed moving from basin to city scale with the aim to test the ability of GRs to mitigate the urban flooding using SWMM. Satellite images available in Google Earth have been used to evaluate the suitability for green roof retrofit in Preturo municipality. According to building attributes for GR retrofit, a percentage of GR conversion of about of 7% has been detected resulting in a low attenuation of flooding volume. This finding suggests to couple the GR technology to other Low-Impact-Development practices in order to improve the stormwater reduction.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
