Storm water is rain and melted snow that runs off, primarily from impervious surfaces.Future storm water management is facing the challenges of increased precipitation, asclimate changes, and increased areas of impervious surfaces due to the expansion anddensification of the cities. Impervious surfaces reduce the potential for water to infiltratein the ground leading to increased surface Runoff and higher peak discharge.The Runoff coefficient is closely related to the percentage of impervious surfaces andrepresents the maximum percentage of a catchment that can contribute to Runoff. In thisstudy, the objective was to evaluate the weighted Runoff coefficient for three differenturban types; apartment buildings, townhouses and residential areas and a comparisonbetween today and the 1970`s was made.The Runoff coefficient was determined by manual mapping of the different surface typesin each area based on data in the form of orthophotos and aerial photographs. The surfacetypes that were mapped were asphalt, permeable areas, tiles, sand/gravel and roof.Tiles and sand/gravel were the most difficult surface types to map. In order to see towhat extent these categories influenced the weighted Runoff coefficient a sensitivityanalysis was carried out and the Runoff coefficient based on surface type was changed indifferent scenarios.The results of the sensitivity analysis showed that the surface types tiles and sand/gravelhad little impact on the weighted Runoff coefficient which in mainly due to the fact thatthe percentage of these surfaces types of the total area is small.The result of the study showed that the largest change in the Runoff coefficient occurredin residential areas where the increase in the percentage of impervious surfaces causedby new roofs in the form of porches and garages and from paved or tiled driveways.

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.

Agricultural drainage is widely used to manage the amount of water in the ground in order to improve conditions for cultivation. However the effects of drainage companies on water regimes are considerable leading to Runoff changes such as altered stream flows, peak flows and water levels. In a greater extent this could imply an increased risk for floods along affected watercourses. This study analyzes the extension of agricultural drainage within the drainage basin of Trosaån in Sweden by ArcGIS mapping. In a statistical analysis, historical variation in streamflow in relation to mean precipitation and mean temperature are investigated for the study area.

Soil properties affect the chemical composition of soil water. When studying transport of chemical substances through a basin, it is therefore important to know from which soil layer the main part of the Runoff is generated. The aim of this study is to develop an HBV/PULSE model with merged soil moisture and response routines, which generates good approximations of groundwater levels. It should be possible to extend the model to simulate transport of substances and take into account which soil layer the groundwater level is currently in. The hydrological version of HBV/PULSE is used since there is no need to account for pH or alcalinity at this stage.

Due to excess precipitation that cause Runoff, all soils in Sweden naturally leaches nitrogen.High leaching from arable land is an environmental problem when the Runoff reacheswaters. In the international agreement, Baltic Sea Action Plan, the aim is to reduce theRunoff of nutrients. Sweden has agreed to reduce its load of e.g. nitrogen to the Baltic Sea.One of the proposed measures is an increased use of site-specific N-fertilization, which hasbeen shown to increase nitrogen use efficiency and therefore also reduce the nitrogen Runoff.Either yields are increased with the same total amount of nitrogen, or the total quantityof nitrogen is reduced with preserved yield levels, which is profitable for the farmers.The dynamics of nitrogen leaching differs between top dressing applications above orbelow the economical optimum. There is a consensus about a difference in the dynamics,but not about its magnitude.

In times of increased flooding, enhanced by climate change, polluted stormwater poses an increased threat to the environment through contaminated water entering waterways. Bioretention utilizes natural processes in soil and vegetation to treat pollutants and combat this threat. Biochar produced through pyrolysis, has a high cation exchange capacity (CEC) and could therefore increase treatment in bioretention systems. This research applies a literature review, interview, and a model to explore the benefits and disadvantages of biochar in order to specify a soil-mix through an understanding of the production process and preferred application rate. High purification through CEC, increased water holding capacity, and carbon sequestration being the benefits discussed.

The eutrophication of lakes and seas with the algal bloom and deficiency inoxygen that follow, has been given priority by the Swedish government as oneof 16 environmental objectives. The purpose of this project was to develop a toolbased on a simple model, limited amount of data and geographic informationsystem (GIS) to identify areas with risk for phosphorus losses due to surfaceRunoff. This tool can act as a decision support to decide where appropriatemeasures should be applied with the aim of reducing phosphorus losses and bythat the eutrophication.The method that has been used is a combination of two models, one calculatingthe potential erosion while the other one identifies areas of erosion (net erosion)or deposition. This ability is of great importance because potential erosionshould be calculated on areas with net erosion. Areas with high potential erosionhave an increased risk for phosphorus losses due to surface Runoff.The potential erosion was calculated based on factors which describe how topography(LS), land use (C), soil type (K) and precipitation (R) effect the erosion.All of them have been modified to a greater or lesser extent.

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.

Sveriges avloppsledningsnät förnyas och utvidgas kontinuerligt. Idag finns ett flertal datorprogram för hydraulisk modellering av flöden och uppdämningsnivåer i spill- och dagvattennät. Modellerna kan även användas som planeringsverktyg för att bedöma effekter av planerade åtgärder samt för uppföljning av utförda åtgärder. Vid uppbyggnaden av en modell krävs beräkningsresultat från en hydrologisk avrinningsmodell som indata. Det största arbetet vid modelluppbyggandet ligger just i beskrivningen av hydrologin.

The aim of this paper is to describe which view the Chinese government in connection with the Olympics wants to display for the natural world and analyze if this view coincide with China?s foreign-policy goals. A qualitative content analysis is used. By using the theory of rational choice and a model with three different political approaches I want to examine whether or not the foreign-policy goals of the Chinese regime comport with the view that displays in two major newspapers in China. Since the Runoff voting in Moscow in 2001 for the 2008 Olympics the Chinese government has been able to act rational and to compose different strategies to use the Games in Beijing for political propaganda.

The purpose of this essay is to find out if liming with Ca(OH2) and CaO can reduce leachingof phosphorus from agricultural land and the problem with eutrophication. This purpose alsoincludes getting knowledge about how to make the phosphorus retained in the soil and beaccessible for the plants. This essay is supposed to show if more research is needed in thissubject. There has not been much research about this subject and therefore the amount ofmaterial to study is limited in this literature review. The research reports that have beenstudied have similar results.

Phosphorus is essential to all plants and is taken up from the soil as the ion H2PO4 - (and to some extent HPO42-). Plant availability depends on, among other factors, the soil pH. In order to provide for plant available phosphorus, it is applied as mineral fertilizers and farmyard manure. However, that causes phosphorus leaching from arable land to surrounding surface waters and lakes and contributes to the eutrofication. There are three types of soils in Sweden that are at higher risk of contributing to phosphorus leakage.

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.

Large amounts of phosphorus (P) are lost from the arable land due to water erosion. Both phosphorus attached to particles and dissolved phosphorus (mainly phosphate) are transported away with drainage-water and surface Runoff. Good soil structure is important in minimizing these losses. In this study, soils from 50 fields were analysed with respect to aggregate stability as measured by dispersion of clay together with the content of total phosphorus (TotP), particulate phosphorus (PP) and phosphate phosphorus (PO4P) in the water phase. All soils were clay soils with clay content varying between 21 and 54%.

To investigate effects of nitrogen on in-lake CO2 and CH4 production during winter, three pair of lakes was subject for a fertilizing experiment in which one lake in each pair was fertilized with nitric acid (HNO3) directly into the water column in the summer of 2012. The lakes in each pair are assumed to be morphologically, hydrologically and biologically similar, that is, the non-fertilized lakes are considered references. The pairs do differ in one major way by being progressively less humic, going from around 25 mg/l to 10 mg/l DOC. Sampling and analysis was carried out at the end of the frozen period in 2013. Results show a significantly higher concentration of both CO2 (p<0,001) and CH4 (?=0,1, p=0,053) between impact and reference sites in the two less humic pairs.