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Lokal dagvattenhantering med grönytefaktorn

Dufbäck, Sanna LU (2012) In Examensarbete INES NGEK01 20112
Dept of Physical Geography and Ecosystem Science
Abstract
In cities hard surfaces prevent rainwater from infiltrating to the ground, which causes runoff,stormwater, that needs to be taken care of. With future changes in climate patterns winters in Scania, southern Sweden, will be warmer, with more rain and less snow and more days with more than 10 mm of precipitation. More intensive rains increase the chance of flooding of urban drainage systems. Open sewer systems and local stormwater treatment have become ways to combine stormwater treatment with green space in the cities. Best Management Practices (BMPs) are used within open sewer systems to retain, store and infiltrate precipitation. At the same time the Biotope Area Factor (or Green Area Factor) has become more commonly used as a method to... (More)
In cities hard surfaces prevent rainwater from infiltrating to the ground, which causes runoff,stormwater, that needs to be taken care of. With future changes in climate patterns winters in Scania, southern Sweden, will be warmer, with more rain and less snow and more days with more than 10 mm of precipitation. More intensive rains increase the chance of flooding of urban drainage systems. Open sewer systems and local stormwater treatment have become ways to combine stormwater treatment with green space in the cities. Best Management Practices (BMPs) are used within open sewer systems to retain, store and infiltrate precipitation. At the same time the Biotope Area Factor (or Green Area Factor) has become more commonly used as a method to improve the ecological situation of cities. It rates different categories of surfaces after ecological functions, among others, their ability to evapotranspirate, retain and infiltrate precipitation and stormwater. In this paper it is investigated whether the Biotope Area Factor can be used as an instrument to implement local stormwater treatment on private property in cities. The weightings (between 1,0 and 0,0)of
the categories in the Biotope Area Factor developed in Malmö, Sweden in 1999 are compared with calculations on the same categories' ability to store, intercept and/or infiltrate precipitation from twenty storms with a frequency between 1 and 10 years and a duration between 1 and 24 hours. The results show that some of the weightings of the categories used in the Biotope Area Factor correspond to their calculated weightings, while other weightings are either overestimated or underestimated compared to their hydrological function. Using the Biotope Area Factor improves the surfaces' ability to store, intercept and/or infiltrate precipitation, yet for it to be used as an instrument to implement local stormwater treatment on private property in cities the weightings need to be modified to better correspond to the categories' hydrological function. The calculations should be based on design storms of a certain frequency and duration optimized to the peak flow capacity of the existing sewer system. The weightings need to be compiled with scientific methods and adjusted to local circumstances. (Less)
Abstract (Swedish)
Populärvetenskaplig sammanfattning: Städernas hårdgjorda ytor hindrar nederbörd från att infiltrera ner i marken, vilket ger dagvatten som måste tas om hand. I och med ett framtida ändrat klimat kommer vintrarna i Skåne att bli varmare, med mer regn och mindre snö och antalet dagar med kraftig nederbörd att bli fler. Med mer intensiva regn ökar risken att städernas vattenledningsnät översvämmas. Öppen dagvatten- hantering och lokalt omhändertagande av dagvatten (LOD) har blivit vanligare som sätt att kombinera dagvattenhantering med gröna ytor i städerna. Olika tekniker, så kallade BMP:s (efter engelskans ”best management practice”) används inom öppen dagvattenhantering och LOD för att hålla tillbaka, lagra och infiltrera nederbörd.... (More)
Populärvetenskaplig sammanfattning: Städernas hårdgjorda ytor hindrar nederbörd från att infiltrera ner i marken, vilket ger dagvatten som måste tas om hand. I och med ett framtida ändrat klimat kommer vintrarna i Skåne att bli varmare, med mer regn och mindre snö och antalet dagar med kraftig nederbörd att bli fler. Med mer intensiva regn ökar risken att städernas vattenledningsnät översvämmas. Öppen dagvatten- hantering och lokalt omhändertagande av dagvatten (LOD) har blivit vanligare som sätt att kombinera dagvattenhantering med gröna ytor i städerna. Olika tekniker, så kallade BMP:s (efter engelskans ”best management practice”) används inom öppen dagvattenhantering och LOD för att hålla tillbaka, lagra och infiltrera nederbörd. Samtidigt har grönytefaktorn blivit en allt vanligare metod för att förbättra den ekologiska situationen i städerna. I den värderas olika sorters ytor (grönytekategorier) efter hur väl de fyller olika ekologiska funktioner, bland dem förmåga att evapotranspi- rera, hålla tillbaka och infiltrera nederbörd. I det här arbetet undersöks huruvida grönytefaktorn kan användas som ett verktyg för att implementera LOD på privat mark i städerna. Malmö stads grön- ytefaktor från 1999, där grönytekategorierna tilldelas delfaktorer mellan 1,0 och 0,0, jämförs med beräkningar av de olika grönytekategoriernas förmåga att lagra, interceptera eller infiltrera nederbörd vid tjugo nederbördsvolymer med återkomsttider på mellan ett och tio år. Resultaten visade att vissa av grönytekategoriernas delfaktorer överensstämde med beräknade delfaktorer, medan andra antingen var övervärderade eller undervärderade i förhållande till kategoriernas hydrologiska funktion. Genom att använda grönytefaktorn ökar ytornas förmåga att lagra, interceptera och/eller infiltrera nederbörd, men för att grönytefaktorn ska kunna användas som ett verktyg för LOD bör delfaktorerna modifieras så att de bättre motsvarar kategoriernas hydrologiska funktion. Beräkningarna bör baseras på designregn av en viss återkomsttid och varaktighet som optimeras efter det befintliga ledningsnätets flödeskapacitet. Delfaktorerna bör vara vetenskapligt framtagna och anpassade till den plats de ska implementeras på. (Less)
Please use this url to cite or link to this publication:
author
Dufbäck, Sanna LU
supervisor
organization
alternative title
Local stormwater management using the biotope area factor
course
NGEK01 20112
year
type
M2 - Bachelor Degree
subject
keywords
öppen dagvattenhantering, BMPs, local stormwater treatment, open sewer systems, biotope area factor, best management practice BMP, LOD, grönytefaktorn, geography, physical geography
publication/series
Examensarbete INES
report number
235
language
Swedish
id
2595656
date added to LUP
2012-06-12 13:49:54
date last changed
2012-08-21 12:26:04
@misc{2595656,
  abstract     = {In cities hard surfaces prevent rainwater from infiltrating to the ground, which causes runoff,stormwater, that needs to be taken care of. With future changes in climate patterns winters in Scania, southern Sweden, will be warmer, with more rain and less snow and more days with more than 10 mm of precipitation. More intensive rains increase the chance of flooding of urban drainage systems. Open sewer systems and local stormwater treatment have become ways to combine stormwater treatment with green space in the cities. Best Management Practices (BMPs) are used within open sewer systems to retain, store and infiltrate precipitation. At the same time the Biotope Area Factor (or Green Area Factor) has become more commonly used as a method to improve the ecological situation of cities. It rates different categories of surfaces after ecological functions, among others, their ability to evapotranspirate, retain and infiltrate precipitation and stormwater. In this paper it is investigated whether the Biotope Area Factor can be used as an instrument to implement local stormwater treatment on private property in cities. The weightings (between 1,0 and 0,0)of
the categories in the Biotope Area Factor developed in Malmö, Sweden in 1999 are compared with calculations on the same categories' ability to store, intercept and/or infiltrate precipitation from twenty storms with a frequency between 1 and 10 years and a duration between 1 and 24 hours. The results show that some of the weightings of the categories used in the Biotope Area Factor correspond to their calculated weightings, while other weightings are either overestimated or underestimated compared to their hydrological function. Using the Biotope Area Factor improves the surfaces' ability to store, intercept and/or infiltrate precipitation, yet for it to be used as an instrument to implement local stormwater treatment on private property in cities the weightings need to be modified to better correspond to the categories' hydrological function. The calculations should be based on design storms of a certain frequency and duration optimized to the peak flow capacity of the existing sewer system. The weightings need to be compiled with scientific methods and adjusted to local circumstances.},
  author       = {Dufbäck, Sanna},
  keyword      = {öppen dagvattenhantering,BMPs,local stormwater treatment,open sewer systems,biotope area factor,best management practice BMP,LOD,grönytefaktorn,geography,physical geography},
  language     = {swe},
  note         = {Student Paper},
  series       = {Examensarbete INES},
  title        = {Lokal dagvattenhantering med grönytefaktorn},
  year         = {2012},
}