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1809 Uppsatser om Water depth - Sida 1 av 121
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.
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.
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.
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.
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.
Pre-spawning habitat selection of subarctic brown trout (Salmo trutta L.) in the river Vindelälven, Sweden
Habitat selection of migratory brown trout at the upper reaches of River Vindelälven, wasstudied in September during the pre-spawning period. The fish migrate from down- orupriver lakes for spawning in the river and data was collected by habitat mapping andradio-telemetry. Habitat selection of fish was analysed with preference curves andstatistical modelling, using the physical variables; depth, stream velocity and streambedsubstrate. Preference curves were derived by comparing fish habitat use with their nearbyavailable environment while the statistical modelling aimed to answer three main questions.1) Do the trout have a specific preference of depth, water velocity and streambed substrate?2) Is there any difference in habitat selection between sexes? 3) Is there a shift in habitatselection over time? The preference curves indicated that trout favored Water depths of 1-2m, velocity compositions characterized as glides (c.
Vattenskydd och krisberedskap hos allmän dricksvattenproduktion : Skydd av täkter, tillgång till reservvattentäkter och andra nödvattenlösningar hos svenska vattenproducenter
The objective of this report was to analyse and compare vulnerability and preparation in Swedish municipal drinking water production, in case the commonly used water sources were inoperative. Methods used were a questionnaire and a less extensive study of regulations for water protection areas. The questionnaire was answered by 41 Swedish municipalities. A handful of them were companies co-owned by a few municipalities. Only one out of four municipalities had source protection areas to all their water sources and for many sources the protection was not satisfactory.
Järnets förekomst i grundvattnet i isälvsavlagringar i Dalarna : Bakgrundshalter och rörmaterialets inverkan vid grundvattenprovtagning
A study has been performed that investigates the variation of iron content in groundwater.The study was initiated by Midvatten AB, which noticed that the iron content in groundwater samples can vary greatly over small distances. The purpose of this study was to geochemically and geohydrologically determine the factors that influence the content of iron and manganese in groundwater from a selection of eskers in Dalarna, and determine how to best sample groundwater with the method used by Midvatten AB. An evaluation was made of how the vertical variation in soil material, water composition, pumping time and pipe material affects the content of iron in groundwater. Piper diagrams were used to study the relationship between the chemical composition of the groundwater and the content of iron and manganese in groundwater samples from the studied areas. The groundwater from the studied areas was then classified in the Piper diagrams, according to the content of the major ions.
Hyllie vattenpark : ett gestaltningsförslag
This project is focusing on a future park that will surround Hyllie water
tower in the outskirts of Malmö. The water tower will be located in the
central part of the new building area Hyllievång. The park will function
as a town park with a special focus on water. The water council of the
municipality, Va-verket, has for the last 7 years built up and been in
charge for a pedagogical programme in the water tower, were schoolchildren
come to learn about the cycle of water and how we use water
in our daily life. In the park they want to build a new part that gives
experience of water, as a compliment to the information in the tower.
What will that park look like, and what shall it be constructed of?
How do you bring water to the surface in a park? How can landscape
architecture work to enhance the presence of water and make people
more interested in water issues? In the search to find the answers to all
my questions I have meet with people, read books and visited different
places.
Saltvattenpåverkan i enskilda brunnar i kustnära områden : En undersökning av grundvattenförhållandena och riskerna för saltvattenpåverkan i S:t Annas skärgård, Östergötland
Coastal areas are popular for housing, both for permanent living and holiday houses. At the same time, thin sediments and small storage capacity in the bedrock makes the ground water resources limited. The limited ground water resources combined with too large withdrawals of ground water makes salt water intrusion a problem in many coastal areas. This study examine the risk of salt water intrusion in drinking water supplying wells on the island Södra Finnö in S:t Anna archipelago, Östergötland, Sweden. A calculation of the relation between ground water recharge and withdrawal is obtained to analyze the ground water balance in the area.