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4047 Uppsatser om Soil water content - Sida 7 av 270
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.
Effekter av bearbetningsdjup i plöjningsfri odling
In Sweden, reduced tillage usually means non-inversion tillage, where primary tillage is carried out using chisel ploughs or disc implements. Primary tillage method is mainly determined by the desired soil loosening and the handling of soil residues.
The effect of tillage depth was studied in field experiments in Skåne, Väderstad, Uppsala, Örebro och Västerås in different crops; spring oilseed rape, spring wheat, winter wheat and spring barley.The experiments generally had a randomized block design with the treatments mouldboard ploughing, deep chisel ploughing and shallow chisel ploughing, in some cases also shallow discing and no-tillage. In the experiments the following parameters were determined: seedbed properties, saturated hydraulic conductivity, penetration resistance, number of emerged plants and crop yield (all parameters were not determined in all experiments. Root growth and draught requirement were determined in two separate studies.
There were no significant differences between tillage depths in non-inversion tillage in seedbed properties, plant emergence or root development.
Vattenkvalité i Märstaån : Igenväxning som indikator på närsaltläckage och vattenstatus
The purpose of this study was to examine whether an inventory of the vegetation overgrowth could be used to indicate a locally nutritional impact. The study was conducted at Märstaån where the water runs through a number of agricultural lands that could lead to an increased amount of diffuse emissions of nutrients. The vegetation overgrowth in the water was also studied in relation to shade, meandering and water flow effects on the vegetation. With this method, no definitive conclusions could be drawn.Where the water was shaded, no vegetation overgrowth could be found. Therefor trees should be planted to prevent any future overgrowths.
Askans inverkan på beläggningstendensen i ett biobränsleeldat kraftvärmeverk och växtplatsens påverkan på askegenskaperna :
This report was written by Sofia Ericson and describes the degree thesis with the title: ?Connections between the growing site of bio fuel, the chemical composition of bio fuel ash and the deposit growth in a bio fuel fired boiler.? The purpose of this degree thesis was to avoid melted deposit growth in the bio fuel fired boiler at ENA Kraft in Enköping.
Potassium and sodium are known to lower the melting point of bio fuel ashes and are therefore not wanted in the trees in higher amounts than necessary for the growth. Silicon is also known to be important for the deposit growth but it is not possible to say in general if higher or lower contents of silicon is better. The relation between silicon and other chemical substances is more important than the total amount of silicon.
Plan för multifunktionella buffertzoner längs Vramsån påMalörten AB : s jordbruksfastigheter
To create multifunctional buffer strips along a watercourse in an economically sustainable way requires consideration of many different factors. In this plan we have selected pollutant reduction as the main purpose of the buffer strip. We have also strived to achieve minimal income loss due to reduced production, increased biological diversity, good game preservation that leads to higher income from hunting, aesthetical satisfaction and possibility to profit from available subsidies. This is done mainly to make landowners/farmers more interested in creating buffer strips along water courses.As sand is the dominant type of soil in the area, the water course is less affected by surface runoff compared to if the soil would be clay or some other finer texture. Game preservation and subsidies have therefore been the main factors when establishing the width of the strip, because these require wider buffer strips in some cases.
Allanblackia stuhlmannii ? a tree under current domestication: what are the soil requirements?
Allanblackia is a genus of trees that grows in the rainforests of West, Central and Eastern Africa. Its big fruits contain seeds very rich in oil which has been used by
local communities for cooking and making soaps. The native stands are threatened by overexploitation and the demand for the oil is much greater than the supply.
Domestication programs, aiming at introducing the trees to small holder agroforestry systems, have been started for some of the species. The main aim of this study was to investigate the soil requirements of Allanblackia
stuhlmannii in terms of chemical and physical parameters, as revealed by the soil conditions in native stands. Another aim was to see if these varied along an altitudinal transect.
Vatten som säkerhetsfråga : Med FN:s konstruktion av vattenfrågan som utgångspunkt
ABSTRACTThe aim of this study is to analyse if the UN today constructs the water issue as a security issue and to argue about in which way the organization in that case does so alternatively why it can be said that the UN doesn?t construct the water issue as a security issue.In order to reach this purpose the following questions will be answered:?Does the UN construct the water issue as a security issue today?-If yes, in which way?-If no, why can it be said that the organisation doesn?t?The methods used are qualitative literature studies of policy documents on water from the UN. The focus is to analyze the ideas about water and to apply my theory on the concept of security, which is Barry Buzan?s framework on security, to these ideas.The main results showed that the UN strongly constructs the water issue as an environmental security issue for environments and species and in relatively strong terms also constructs it as an environmental security issue for civilisations. In rare cases the organisation constructs it as a societal security issue, but the UN doesn?t construct the water issue as a military, political or economic security issue..
Plan för multifunktionella buffertzoner längs Vramsån på Malörten AB: s jordbruksfastigheter
To create multifunctional buffer strips along a watercourse in an economically sustainable way requires consideration of many different factors. In this plan we have selected pollutant reduction as the main purpose of the buffer strip. We have also strived to achieve minimal income loss due to reduced production, increased biological diversity, good game preservation that leads to higher income from hunting, aesthetical satisfaction and possibility to profit from available subsidies. This is done mainly to make landowners/farmers more interested in creating buffer strips along water courses.
As sand is the dominant type of soil in the area, the water course is less affected by surface runoff compared to if the soil would be clay or some other finer texture. Game preservation and subsidies have therefore been the main factors when establishing the width of the strip, because these require wider buffer strips in some cases.
Hållbart nyttjande av vattenresurser på Gotland : vision och verklighet
Fresh water has become more and more of a scarce commodity. Water scarcity isn't first and foremost a cause of drought and wasting, but a cause of inequality and mismanagement. This is not only a problem for developing countries, and there can also be variations within countries. The municipality of Gotland has a development program called Vision Gotland 2025, with goals for growth and sustainable development. The aim of this study is to examine whether the use and management of water resources on Gotland and Vision Gotland 2025 is conformed to the Water Framework Directive and the Ecosystem Approach in terms of sustainability.
Perkolationsfilter : En undersökning av reningseffekt med avseende på järn och mangan
This master thesis has been done in cooperation with Sweco Viak AB in Sundsvall. The aimwith the project is to investigate the purifying effect of percolation filter due to iron andmanganese. The overall goal was to investigate how the parameters surface load,sandfractions, and burden time affect the purifying effect. The expectation is to optimize thedesign and find a demouldning of the filter that gives sufficient purifying with a highersurface load. As an attempt to accelerate the curing of the filter, experiments with a layer ofsand which surface has been covered with manganese ore (MnO2) on top of the filter havebeen done.As test filters 10 L bars were used and the experimental work was performed at thewaterworks in Hassela and Munkbysjön.In Hassela different sandfractions were tested.
Föroreningstransport i grundvatten : En modelljämförelse
This thesis compares different methods for risk assessment of a creosote contaminated site in Vansbro, Dalarna. In a complementary study the importance of using representative data for calibration and validation of stationary groundwater models is discussed. The time dependency between surface water levels and groundwater levels on the site in Vansbro is evaluated by step response analysis. The results show that the groundwater levels reflect only long-term variation in the surface water levels. Hence the use of such long-term means for calibration and validation of the stationary groundwater models is the only theoretically defendable alternative.As a first step in the comparison of risk assessment methods the degree of contamination is evaluated on the basis of generic guideline values for contaminated soils, developed by the Swedish Environmental Protection Agency.
Frigörelse av fosfor från färskt, fryst och torkat växtmaterial : ett laboratorieförsök för att öka förståelsen för fosfordynamiken inom växtodlingen
Phosphorus is the single most potent contributor to eutrophication of freshwater and has also been shown to contribute to the toxic algae blooms in the Baltic sea. The
dynamics and paths of losses of phosphorus from arable lands are not fully understood.
It is known that phosphorus can be lost directly from plant material to water.
In studies where plant material has been subjected to several freeze-thaw cycles, large amounts of phosphorus have been lost. Most studies have been conducted
under field conditions, with many factors effecting the measured losses of phosphorus, such as weather and type of soil. This study was performed in a controlled environment without the presence of soil. Instead of soil, small glass beads were mixed with the plant materials in vessels, to make possible homogeneous leaching with water through the mixture of glass beads and plant materials.
In this study, clover, ryegrass and dry straw were cut to pieces, approximately 2 cm long.
Hur en ökad marktemperatur påverkar fotosyntes och markrespiration i en boreal skog
During the year of 2008, a powerful earthquake hit the southern part of Iceland, which changed the geothermal conditions in the area around the city of Hveragerdi. Elevated soil temperatures in a nearby forest plantation have contributed to a unique opportunity for researchers to study how an increased soil temperature affects the boreal forest ecosystem, something that partly can be connected to the climate changes which are happening today. The boreal forest is representing a carbon sink and a buffert for the emissions that occurs. Changes in this ecosystem will for that reason contribute to major impact for the global carbon cycle. To study the impact of how elevated soil temperatures affects different processes in a plantation of Sitka spruce, studies were made on the photosynthesis of the trees and the respiration from the soil.
Hänsyn till mark och vatten vid slutavverkning : en fältstudie på känsliga marker
The purpose of this study is to investigate if there is enough consideration taken to sensitive forest areas close to water or wetlands during clear cutting assignments, and to estimate the extent of damage made by forestry machines used at that time. A field and literature study is used to show how to improve and prevent the damage made in the wake of the machines.
This study is made for Sydved, and shall culminate in a policy to prevent ground damage during their clear cutting assignments.
The areas which were part of the field studies were clearcuttings on fine grained soil close to water and wetlands. The purpose was to find out if the water had been affected, what had been done to prevent ground damages and what more could have been done.
The results of the field studies show that more work needs to be done to reach up to expectations. More information about the assignment area, better planning of sensitive regions, and strengthening of the main haul roads with brush are some of the improvements that can be done. There is also a need for more exact guidelines, follow-ups and education for everyone involved to have the same goals and understanding to prevent ground damage..
Vattnet i vår kropp : Förskolebarns tankar om vattnet innom oss
AbstractThis study deals with preschool children's ideas about water in our body. Ten children with the age of four to five were interviewed individually, the interviews were qualitative. The children were also asked to draw their answers and answer questions about a picture that represented the excretory system. The results of my study show that children did not have any knowledge about the water being vital for us. Preschool children had no knowledge of why it is important to drink water.