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38 Uppsatser om Rivers - Sida 3 av 3
Hydrauliken i Ångersjöns fosforfällor : bestämning av flödesvägar och åtgärdsförslag för optimal fosforbindning vid avloppsrening med reaktiva filter
Discharge of untreated wastewater leads to unnaturally high levels of nitrogen and
phosphorus in Rivers, lakes and the sea, which results in unbalanced ecosystems with
eutrophication and lack of oxygen. Part of the phosphorus in surface waters is coming from
on-site wastewater treatment from scattered households with unsatisfactory purification.
Blast furnace slag is a by-product from iron production, and has in laboratory trials showed good phosphorus binding capacity. To test blast furnace slag as a reactive filter media for phosphorus separation in a full scale experiment, a wastewater treatment plant has been built behind the picnic area at Ångersjön alongside the road E4 in central-eastern Sweden. The plant contains two parallel lines, one with blast furnaces slag and the other with Filtralite-P as phosphorus sorbent. Both filters have showed decreasing phosphorus purification effect with time in spite of a low wastewater load.
Utveckling och tillämpning av en GIS-baserad hydrologisk modell
A distributed hydrological rainfall-runoff model has been developed using a GIS integrated with a dynamic programming module (PCRaster). The model has been developed within the framework of the EU-project TWINBAS at IVL Swedish Environmental Research Institute, and is intended for use in WATSHMAN ? a tool for watershed management developed at IVL. The model simulates runoff from a catchment based on daily mean values of temperature and precipitation. The GIS input data consist of maps with soil type, land-use, lakes, Rivers and a digital elevation model.
Metodikstudie av trollingfisket i Vänern : Jämförelse av fångstrapportering mellan intervjuer och enkäter gjorda på trollingfiskare samt vädrets påverkan på ansträngning
There are five endemic populations of migratory Atlantic salmon (Salmo salar, Salmonidae) and brown trout (Salmo trutta, Salmonidae) remaining in Lake Vänern, whereof two are salmon and three are trout. There is one population of each species in Klarälven, also one of each in Gullspångsälven and there is a population of trout still remaining in Tidan River. Since the beginning of the 20th century endemic populations of salmon and trout have either vanished or declined dramatically due to the construction of hydropower in the Rivers around the lake, and still today the future of the remaining populations remains uncertain. To manage salmonid fishes effectively more knowledge of their ecology throughout their different life-stages is needed. A large part of the Lake Vänern salmonoids lives are spent in the lake, where a mayor mortality factor is recreational fishing, especially angling.
Green feed in the marine fish farming : how to communicate water benchmarks to stakeholders
Global catch fishery is said to been oppressed to its limit (Boyd & Schmittou, 1999), further implying aquaculture might be the only solution to the world demand for fishery products. The applied term aquaculture in this paper refers to the one used by NOAA (2008); breeding, rearing, and harvesting of plants and animals in all kind of water environments, including but not limited to ponds, Rivers, lakes, and the ocean. According to Shamshak & Anderson (2008, p. 74) aquaculture has over the past 20 years been the fastest growing food sector with an average annual growth rate of 8.7%. It further represents approximately 37 % (Shamshak & Anderson, 2008, p.
Vattensänkningar : en analys av orsaker och effekter
There are records of lowering of the water level in a lot of the Swedish lakes from the middleof the 1700th century. The aim was gaining more areable land to meet the needs of more foodto support the expanding population. In areas with top soil which contents of clay or loam asin the southwest of Scania in southern Sweden this was proven to be a successful wayexpanding the total outcome of the harvest.The studied area in the northeast of Scania, though, consists of morain with a lot of mires -much less nutritious conditions. When the water level is lowered the atmosphere gets accessto the peat. The dissolving of the organic matter that has been suppressed by the lack ofoxygene below water level continues.
The vertical farm : varför har idén uppkommit och hur är den tänkt att fungera?
By immersion in the situation of the food production today and a historical study of how past development has led us to this point, one goal of this essay is to discuss whether the current way of farming can be applied in a sustainable future. Another objective of the essay is to study the vision Vertical farming as an alternative approach, and to focus on different aspects of this phenomenon in order to provide as comprehensive a picture as possible.The paper, thus, seeks to broaden the views for alternative approaches regarding a well-established method which we often take for granted. The aim is also to initiate a discussion around the need to also take radical ideas in regard if we want to face the future in a sustainable manner. The method is a qualitative literary study where scientific articles and papers have been used to discuss the issues: why has the idea of Vertical farming arisen, what is Vertical farming and how is the Vertical Farm meant to operate? Does Vertical farming have a place in the sustainable city of the future? For a long time us humans lived as one with nature, in a symbiotic relationship in which we gave and took as a functioning part of an ecosystem.
Välkommen : vackrare infart till Vilhelmina
The purpose of this thesis is to show how a good approach can be designed, focusing on the southern approach to the Swedish town Vilhelmina. Prior to the car being part of everyday life, the approach was a road where the town showed itself from the very best side. When the amount of traffic increased, so did noise and other disturbances, and as a consequence industrial areas replaced the residential buildnings at the approaches. Today, the pendulum is turning back and in recent years the approach is regarded as a place to introduce the town. The approach is also the place where cars should slow down from the speed of the main road to the speed of the city.
Flödesrelaterad spårmetalltransport i några svenska vattendrag
Höga flöden och dess inverkan på spårmetalltransporten är av stort samhällsintresse med klimatförändringarnas redan idag märkbara påverkan. Ökad nederbörd och därmed vattenföring kommer leda till att spårmetalltranporten i våra svenska vattendrag kommer att förändras på sikt. Stora och snabba förändringar, som exempelvis klimatförändringar med extrem nederbörd, temperaturskillnader eller snö är typer av event vilka har visat sig ha direkt eller indirekt påverkan på metallers dynamik i vatten. Även de stigande koncentrationerna av Fe och TOC i våra vattendrag, även kallat brunifiering, vilket gör våra vattendrag allt mörkare i färg, har troligen med klimatförändringarna att göra.Syftet med det här arbetet har varit att samla in analysdata om metalltransporter i sex utvalda vattendrag (Kalixälv, Råneälv, Moälven, Ljungbyån, Ätran och Pipbäcken Nedre) och försöka beskriva dess tillstånd och förändringar i vattenkemin för att se om något samband fanns mellan spårmetallerna och flödesökningar. Valet av studerade vattendrag vilka arbetet fokuserade på avgränsades för möjligheten att kunna studera dessa närmare.