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2539 Uppsatser om Depth-to-Water Index - Sida 1 av 170

Anva?ndning av markfuktighetskartor fo?r sta?ndortsanpassad plantering

Digital depth-to-water maps can be produced from a digital elevation model (DEM). Then GIS- based algorithms are used to calculate water flows and the Depth-to-Water Index classes dry, fresh, moist and wet. The purpose of this study was to investigate the possibility to use depth- to-water maps for site adapted planting.The results showed that use of depth-to-water maps for site adapted planting, roughly halved the proportion of improperly planted surfaces from an average of 9 % to 4 %. The variation in the values of proper surface decreased and the result became more even.. In addition, more pine than spruce was incorrectly planted.

Habitatpreferenser hos tjockskalig målarmussla (Unio crassus) med avseende på vattendjup och beskuggning.

The thick-shelled river mussel (Unio crassus) is a red listed species classified as Endangered (EN) and is also considered within the Habitats Directive. The distribution in Sweden is fragmented and it is mostly occurring in the south eastern parts. We investigated the presence of Unio crassus in a section of the stream Storån, Östergötland County, from Falerum to the inflow into Lake Åkervristen. The environmental parameters investigated were water depth, bottom substrate, shading, water velocity and the slope over the water surface. In this thesis I have focused mainly on water depth and shading, comparing sites with and without mussels.

Kan markfuktighetskartor användas för att hitta skogsmark med hög bonitet? : ett gis-baserat försök med dtw-index och laserskannad övre höjd

The depth-to-water-index (DTW-index) is derived from digital elevation models (DEM) to map soil wetness, in terms of distance from soil surface to the ground water table. The aim of this GIS based study was to investigate the existence of a relationship between DTW-index and forest site productivity (SP). The belief of such an assumed relationship was based on knowledge that the ground water level is related to site properties that can either promote or impede tree growth. Data primarily comprised rasters of the Krycklan catchment in northern Sweden and depicted DTW-index and a laser scanned vegetation height. The 100th height percentile of each pixel in the vegetation raster was assumed to mirror the top-height, letting it act as a relative measure of SP within a delineated area of equal stand age.

Skaftslamkrypa (Elatine hexandra) i Bolmen, utbredning, tillväxt, reproduktion och styrande faktorer

The plants in the genus Elatine are characteristic for oligo and mesotrophic lakes. This study focuses on Elatine hexandra one of the four species in Sweden. It is stated as vulnerable by the National Environment Agency and a conservation plan with guidelines to preserve the plant in Sweden is under preparation. There have been a few previous studies investigating this plant in other countries but this is the first one for Sweden. The aim of this study was to investigate the distribution, growth and reproduction of E.

Topografins inverkan på markvattenhalten i ett jordbruksdominerat avrinningsområde

Topography is an important parameter for catchment hydrology, since it is a driver for water flow. Moreover, topography serves as a basis for hydrological models, e.g. ?Top-model?, which is based on a topographical wetness index (TWI). Few studies of TWI have been conducted on agricultural catchment scale. Four fields were studied in a Swedish drained agricultural catchment in order to evaluate the influence of topography on soil wetness.

Fällning av kisel från avloppsvatten vid Hellisheidarvirkjun - experimentell studie

This report is about the experiments with mixing of the separated water and the vacuum pump seal water at Hellisheiði power plant. This is done to prevent silica scaling and clogging in pipes and reinjection wells as well as eliminating vacuum pump seal water from the plant. The experiments were done in four stages: the first stage comprised of tests with different flows of separated water at 70°C, the second stage was carried out by mixing the separated water at 70°C and the seal water with different amounts of the seal water, the third and the fourth stages were like the first and second but with the separated water at 120°C. The results show that this method is good if the mixture is around 50/50 separated water and seal water, to control the silica scaling in the separated water and to be able to reinject the seal water with the separated water. This does not eliminate the silica scaling in all of the separated water because the amount of separated water is much more than the amount of seal water that comes from the plant. .

Vilken preferens har tjockskalig målarmussla (Unio crassus) för bottensubstrat och vattenhastighet i Storån, Östergötland?

The thick shelled river mussel (Unio crassus) has a fragmented distribution in southern Sweden. It is a threatened and protected species. In both the Swedish red list and the IUCN Red List of Threatened Species Unio crassus is classified as Endangered (EN). Causes for this classification are for instance differentiated bottom substrate and deterioration in water quality. In this study, habitat preferences of Unio crassus were investigated to assist in future restoration work.

Underkambriska böljeslagsmärkens bildningsmiljö : Ett försök att fastställa fossila ripplars avsättningsmiljö med hjälp av recenta sandbottnar

ABSTRACTThe fauna of the Lower Cambrian is far from fully understood, as is the environment of that epoch. Some of the most crucial moments in the history of evolution takes place during this epoch; the Cambrian explosion and the appearance of ecosystems as we know them. That makes it an important period to investigate. Doing so, the Lower Cambrian offers a lot of problems, one of which is that body fossils are seldom preserved. That has often left us with trace fossils to create an image of the Lower Cambrian life, but also some bedrock features such as ripple marks.The main purpose of this work has been to investigate the possibilities of relating the wave lengths and forms of recent wave-generated ripples to fossil ones, and also to evaluate the methods for that kind of comparison.

Empirisk undersökning av aktieindexobligationer : Till vilken grad tar innehavaren del av underliggande index avkastning?

The purpose of this essay is to evaluate stock index bonds return to risk ratio in order to investigate to which degree an investor in a stock index bond take part of the underlying index return and what the investor must pay for the security of not losing his funds. In order to carry out this evaluation an average return per year and the Sharpe ratio will be calculated and a mean- standard deviation analysis will be made. All investigated stock index bonds are based on a Swedish underlying asset.The results show that the stock index bonds haven?t generated a higher risk adjusted return than its underlying asset. The stock index bonds took part of 57 % of the underlying assets return, and the loss of 10 percentage points per year for the stock index bonds compared to its underlying asset can be seen as the cost for the guarantee a stock index bond gives..

Redogörelse av marknadsstyrka på den svenska elmarknaden

Denna uppsats syfte är att förklara den svenska elmarknadens konkurrenssituation med Lerner index och Herfindahl index. Genom att estimera priselasticiteten med en ekonometrisk modell som logaritmerats kunde dess värde skattas fram. Vidare har denna elasticitet använts för att skatta fram Lerner index. Avslutningsvis har ett Herfindahl index beräknats för att mäta marknadens koncentration. Resultatet från empirin visar existens av marknadsstyrka på elmarknaden och att den är oligopolistisk..

Vattenbehov och olika system för vattentilldelning till nyavvanda grisar :

We all know that water is very important for both animals and humans. When we are weaning the piglets from the sow we must guarantee that the piglets can start to drink more water instead of sow milk. The first thing to check is always the quality of the water that is to be used. To secure that, you must take a water sample. If the water is inadequate it can bring a lot of problems and diseases.

Brunnsviken : Utvärdering av åtgärder för förbättrad vattenkvalitet

Periods of hypoxia are a recurring issue in Brunnsviken. Main factors that trigger hypoxia in Brunnsviken are eutrophication  due to anthropogenic emission of nutrients, stratification in the water column due to salinity and temperature differences  that prevents mixing and a sill inlet that prevents water exchange. As an attempt to improve the oxygen levels, bottom water is pumped from Brunnsviken causing aerated surface water to flow back into the basin.  The objective of this Master?s thesis was to study the change in dissolved oxygen levels due to pumping.

Pricing Credit Default Index Swaptions A numerical evaluation of pricing models

This study examines the background and nature of the credit default index swaption (CDIS) and presentsrelevant methods for modelling credit risk. A CDIS is a credit derivative contract that gives the buyerright to enter into a credit default index swap (CDS index) contract at a given point in time. ACDS index, in turn, is a multi-name credit default swap (CDS). Within the eld of research, thisthesis identi es the CDIS pricing models presented by Jackson (2005), Rutkowski & Armstrong (2009)and Morini & Brigo (2011) as the most recognized and developed. These models are evaluated byreconstruction in a numerical software environment.

Översyn av vattenskyddsföreskrifter med tillhörande vattenskyddsområde i Hallstahammars kommun. : Vilka revideringsbehov finns?

Water is an important food and an important natural resource. In order to protect these are the Environmental Code and the EU directive given to water protection and related water protection regulations will be established for all water sources until 2010. Those who will prepare a water protection and related water protection regulations is the municipality or person responsible for water supply. The person then decides and declares the area as water protection and related water protection regulations are municipal or provincial government. The idea of creating a water protection is to protect the water supply and the body of water against pollution caused by point sources, diffuse sources and accidents combined.

Aktivt system för tidvattenreglering av Lysekilsprojektets vågkraftsteknik

This report investigates a possible solution to the problem with adapting wave powerplants to work in countries with tidal water. The wire connecting the buoy at the surface with the generator at the bottom needs to adjust to the varying water depth. Our solution to this problem is to attach the wire to a jack which is then placed inside the buoy. The jack is then powered by an electric engine. The report discuss what forces the buoy will be exposed to and then the structural integrity of the design is evaluated through simulations.

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