| Summary: | When the earth’s surface is covered with impervious materials, as often happens when land is developed, it becomes impermeable to water (some speak of this as “soil sealing”). This can lead to changes in water flow patterns, increased pressure on sewage and stormwater facilities, and a greater risk of flooding in wet weather. This report examines impervious surface cover in various parts of Reykjavík and relates its extent to population density and to automobile ownership and usage. In addition, the relationship between the percentage of impervious surfaces in watersheds and water quality and flow are investigated. A geographical information system was used for calculations based on existing impervious surface maps. The last part of the report presents a proposal for increasing soil permeability in the neighborhoods studied. It was found that the impervious surface per person increases with a decreasing population and workplace density and most impervious surface is devoted to motorised transportation. The percentage of impervious surfaces in the drainage area or watersheds is correlated with the flow caused by rain in the pumping stations and with water pollution, represented by the conductivity and total concentration of metals. Based on the findings of the study, urban densification can be proposed as a means to reduce the amount of impervious surface per capita, and stormwater infiltration is in many cases a feasible option to mitigate the impacts of soil sealing. Þegar yfirborð jarðar er þakið vatnsheldum efnum, oft í tengslum við borgar- og þéttbýlismyndun, dregur úr gegndræpi jarðvegs. Þetta getur m.a. leitt til breytts vatnsbúskapar, aukins álags á fráveitukerfi og aukinnar hættu á flóðum í miklum vatnsveðrum. Í verkefninu var þekja ógegndræps yfirborðs í Reykjavík greind eftir hverfum og sett í samhengi við íbúa- og starfsþéttleika og samgöngur. Tengslin milli hlutfalls af ógegndræpu yfirborði á vatnasviðum og vatnsgæða og rennslis voru rannsökuð. Notuð voru m.a. fyrirliggjandi kort sem sýna ...
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