This master thesis covers the seasonal planning of a small scale hydropower system. The system in this study is owned and operated by Mälarenergi Vattenkraft AB. The total system consists of 4 different main Rivers with 24 hydropower stations and several dams. The total installed power in the system is 43.75 MW. Most of the hydropower stations are regarded as small scale hydropower stations and thus entitled to green certificates.In this report the issue of planning is formulated as an optimization problem.

The possibility for plants to utilize phosphorus in soil is a prerequisite for conducting agricultural production, both small scale and professional. Spreading of phosphorus fertilizers and manure is therefore seen as a necessity in today's agriculture in order to achieve high yield. Manure management, livestock farming and manure storage could contribute to the eutrophication of lakes and Rivers. For instance, when the ground becomes saturated, phosphorus leakage could be seen in surface runoff or in point sources resulting from inadequate manure storage management.In the municipality of Växjö there is still many bodies of water that do not reach the Swedish environmental water quality standard of "good ecological status". This thesis has therefore analyzed the manure management and storage on agricultural farms which may have contributed to eutrophication in the municipality.The method for this thesis was a literature study, a questionnaire survey with 820 receivers and a summary of issued inspection reports from 2013.The results highlight the ways in which agriculture may have contributed to the eutrophication of lakes and streams in the municipality of Växjö.

Modelling of pollutants is commonly used in research and at departments working with environmental issues. The need to use large amounts of data when modelling creates the opportunity for more generalised models with lower data demands. Aggregating functions into coarser elements is a sort of generalisation of actual features in nature.A development of a method and a modelling tool called ?KadmiumKalkylatorn? has been performed to model cadmium pollution in Rivers in Skåne, Sweden. The water runoff has been multiplied with cadmium standard concentrations based on membership in landuse classes.

The stretch from the riparian zone of a major river, through the mouth and upstream in tributaries forms a range of differing habitats. The aim of this study was to investigate the effect of these different habitats on the riparian frog community in primary rain forest in Borneo; i.e. examine whether any gradients could be demonstrated in terms of species composition, diversity and density of frogs, as well as which environmental characteristics that seem to be of most importance in forming habitats of high conservational value. A major river, Segama, and three of its tributaries were investigated. The surveys were carried out at night by searching for frogs visually and acoustically along the streams, from the shore of the Segama river and 400 metres upstream in the tributaries.

The purpose with this study is to find out how much dead wood we can expect us to find in a Russian reference river and compare with studies from Swedish streams. Dead wood are an important structure for the biodiversity in forest streams, studies have shown that population of trout can increase with up to 300 % when the amount of dead wood are increasing from 0 to 8 ? 16 LWD (Large woody debris)/100 m2. Dead wood are also an important structure for the stream character, formations of dams and pools which are important habitats and reproduction areas for salmon and brown trout. The study where taken place in tributaries to the Russian river Varzuga in the North West part of Russia outside Murmansk. Varzuga has low impact of human activity and is considered to be a reference river to Rivers in northern Sweden.

Forestry is increasing on an industrial scale where collection of logging residues takes a greater part. This has resulted in more machinery and heavy machinery driving in the clear felled area, this increases the risk of soil damage that will occur in the form of soil compacting and rutting in the clearings. This affecting on the nature in a negative way and especially in Rivers and lakes that are affected by siltation and acidification leading to increased levels of heavy metals and methyl mercury. The purpose of this study was to investigate why there is damage to the ground when working with the slash in forest management from the forest officer point of view. A self-designed questionnaire was used and 45 questionnaires were sent out to various companies all over Sweden.

The purpose of the thesis was to map the hydraulic load on the Knivsta river from stormwater runoff, and build a platform for further studies of pollution loads on the Rivers ecosystems. New residential areas are planned to be built in Knivsta municipality and it will have an impact on stormwater flows to Knivsta river. To examine the impact this will have, simulations were made in the area as it stands today and after expansion work. The work includes calculation of flows from the populated areas but also from the catchment area around it consisting of woodlands and fields. Because of expected climatic changes which may affect rainfall, the simulations have been performed with different return periods for rainfall data.

Due to exploitation of the world?s Rivers, the upstream migration of anadromous species is frequently delayed or even prevented. To mitigate these problems and allow fish to migrate past obstacles, structures such as fish ladders have been developed. However, recent studies show that many of the present fish passage facilities are deficient. Monitoring and evaluation of passage facilities is therefore crucial to enable necessary adjustments.

Deciduous forests are, according to the National Environmental Quality Objectives, a priority area. Deciduous forests are rich in species and the occurrence of dead wood is an important factor for biodiversity. In order to identify valuable deciduous forests for bio-diversity, conservation needs good analyses and planning tools. Habitat models combined with geographic information systems can be used to study the spatial structure of suitable habitat. The Lesser spotted woodpecker (Dendrocopos minor) has been proposed as an indicator species for deciduous forests, since this species is highly specialized on insect larvae in dead wood and requires large areas of deciduous-rich environments. Many riparian forest with high species richness and high nature conservation values are found along the Ume river in Umeå municipality.

A large number of Rivers in northern Sweden have hydropower developments that cause negative effects on both up- and downstream migrations of anadromous species like Atlantic salmon. So far, most attention has focused on the hindrances of adult fish during their upstream spawning migration. However, since turbines in power stations cause losses on downstream passing fish, the focus on negative effects on smolts has increased. The aim of this study was to compare three different causes of losses of salmon smolts passing downstream through a power station area in the flow-controlled River Åbyälven in northern Sweden.A total of 61 wild salmon smolts were caught and radio-tagged in the River Åbyälven during their downstream migration in June 2009. The salmon smolts were released at three locations, 1.1 km upstream from the power station, in the turbine intake and in the upper part of a fishway, acting both for up- and downstream fish passage.

Stage-discharge equations for lakes without disharge measurementsSimon AnderssonIn 2015 all lakes, Rivers, coastal water and groundwater should be of good ecological statusaccording to the water framework directive from the European Union. In the process ofimproving the quality of Swedish water bodies, knowledge of where problems occur isneeded in order to utilize the resources optimally. The ability of lakes to store water is animportant factor since it controls the flow of water through the country. A stage-dischargeequation is a mathematical relation between discharge from a lake and its water level. Bybetter understanding of stage-discharge equations for lakes, their storage capacity can bedescribed better in hydrological models.This master thesis aims to evaluate methods for determining stage-discharge equations forlakes where a variable amount of field measurements is available.

Eutrophication is an environmental problem that affects more than ten percent of Swedish lakes. Excess nutrients increase the growth of algae, and cause major problems in the ecosystem through oxygen-free bottoms, fish kills, and at worst dead bottoms. Agriculture accounts for 44% of human emissions of phosphorus to lakes and Rivers. Leaching occurs of particle bound phosphorus and of dissolved phosphate. The amount of phosphate in the soil solution that may be leached is partly due to the prevailing pH in the soil solution. The purpose of this study was to investigate how the relationship between phosphate solubility and pH was affected by liming.

Nitrogen deposition leads to environmental damage in areas where the nitrogen deposition is high. Southwest Sweden receives an annual nitrogen deposition of up to 20 kg N/ha. Nitrogen that is not assimilated by the vegetation is accumulated in the soil, which may lead to nitrogen saturation and an elevated risk of nitrogen leaching. Nitrogen leaching from forest areas in southern Sweden has proven to be higher than from agricultural areas, which have been thought to be the main contributors to elevated nitrogen levels in Rivers and lakes. The amount of nitrogen that leaches depends on the fraction of the total nitrogen in the soil that consists of nitrate, since nitrate is easily transported through the soil.

Deicing fluids based on Propylene glycol are used at Stockholm Arlanda airport to remove or prevent ice on aircrafts. The high oxygen demand of propylene glycol can cause oxygen depletion in Rivers downstream from the airport if not collected. Mass balance calculations made by Swedavia indicate that the actual amount of gathered propylene glycol is underestimated. Suspicions that propylene glycol is degraded in the stormwatersystem designed to collect deicingfluids, called the B-glycolsystem, have to be investigated in order to establish with certainty that no propylene glycol in other ways leaves the B-glycol system.The purpose of this study was to determine if degradation of propylene glycol is present in the B-glycol system and also to estimate the extent of the degradation. Propylene glycols high biological oxygen demand can cause oxygen depletion in waters downstream from Stockholm Arlanda airport if not collected.

On-site sewage systems are common on the countryside of Sweden with approximately one million on-site systems installed. Due to insufficient function, these contribute significantly to the total discharge of phosphorus to Rivers and lakes, causing eutrophication. In order to reduce eutrophication and to fulfil one of the environmental quality objectives, the decision was taken by the Swedish Government in 2005 that 60 % of phosphorous in sewage sludge is to be recycled to arable land before 2015. To make recycling a reality, new solutions have to be found. Federation of Swedish Farmers (LRF) takes an active interest in this issue and has initiated this study. One problem is that the food industry is sceptical towards recirculation due to the risks that products from sewage systems may contain pathogens, heavy metals and unwanted chemical compounds, e.g.