Zugl.: Berlin, Techn. Universiẗat, Diplomarbeit, 2000.

Phosphorous (P) has been found to be the limiting nutrient in freshwater systems, directly affecting rates of planktonic growth. The P circulation is very complex, and its pathways through lake systems are difficult to determine. Motala Ström is the biggest watercourse in the south-east of Sweden and an important source of P to the Baltic Sea. The aim of this study is to conduct a P mass balance analysis of the lakes Roxen and Glan over a period of time. The analysis will also include a quality control of the concentrations data. The P concentration data used in this investigation were collected from the Motala Ström River Association, consisting of seasonal or monthly concentration data of Tot-P during the period 1960-2010. Daily water flow data used in this study were modelled by the Swedish Meteorological and Hydrological Institute (SMHI) using the S-HYPE model. P concentration deviations from monthly averages at each sampling station were calculated, followed by a seasonal Mann Kendall trend analysis. At five out of eight sampling stations, negative trends were detected, indicating decreasing concentrations. The exception was the outflow from lake Glan, Stångån and Finspångsån. Linear interpolation of P concentration data was performed to create daily data for the period 1980-2010. Following interpolation, daily transport values were calculated and summed up to annual values. Lake Roxen has acted as a source of P during the whole period 1980-2010, except for one year. Lake Glan has acted as a source during 22 of the 31 years. There is a tendency of Glan to become more of a source over the years, which is in line with the deviation observations, but variation between years makes it necessary to analyse also future data in order to establish any possible trend in P transports. Before construction of wastewater treatment plants, the lakes were certainly sinks of phosphorus. But at least for Roxen, the switch from sink to source was completed before 1980.

<p>Floods are common natural disaster occurring in most parts of the world. This results in damage to human life and deterioration of environment. There have been immense uses of technology to mitigate measures of flood disaster i.e. structurally and non-structurally. Undoubtedly, structural measures are very expensive and time consuming which involves physical work like construction of dams, reservoirs, bridges, channel improvement, river diversion and other embankments to keep floods away from people. Whereas non-structural measures is concerned with planning like flood forecasting and warning, flood plain zoning, relief and rehabilitation for reducing the risk of flood damage to keep people away from floods. Thus, non-structural measures involve analysis, planning providing spatial information on maps with high accuracy in less time. Non-structural measures can help decision maker to plan an effective emergency response towards flood disaster. A one of the good way to plan non-structural measures is to analyze impact of flood in the flood prone areas. The thesis tries to analyze impact of flood on environment along the demarcated flood prone areas of Lake Roxen and Lake Glan in Östergötland County, Sweden. The thesis also proposes how to use current flood information during flood emergency utilizing geographical information system. This provides spatial information for area in the flood zone for assessment regarding flood vulnerability.</p><p>Using map overlay analysis in GIS software (ArcGIS); flood prone areas and topographic data along Lake Roxen and Lake Glan were digitized from PDF maps. Thus, the thesis work is an effort to analyze impact of flood when areas along Lake Roxen and Lake Glan are flooded. ESRI® GIS software Arc Map 9 and Arc View 3.3 is used for data preparation, integrating, analyzing, and spatial data with attribute table information. Finally, to show GIS can be an effective tool for development of flood emergency system as a part of disaster preparedness by the decision makers.</p>

Floods are common natural disaster occurring in most parts of the world. This results in damage to human life and deterioration of environment. There have been immense uses of technology to mitigate measures of flood disaster i.e. structurally and non-structurally. Undoubtedly, structural measures are very expensive and time consuming which involves physical work like construction of dams, reservoirs, bridges, channel improvement, river diversion and other embankments to keep floods away from people. Whereas non-structural measures is concerned with planning like flood forecasting and warning, flood plain zoning, relief and rehabilitation for reducing the risk of flood damage to keep people away from floods. Thus, non-structural measures involve analysis, planning providing spatial information on maps with high accuracy in less time. Non-structural measures can help decision maker to plan an effective emergency response towards flood disaster. A one of the good way to plan non-structural measures is to analyze impact of flood in the flood prone areas. The thesis tries to analyze impact of flood on environment along the demarcated flood prone areas of Lake Roxen and Lake Glan in Östergötland County, Sweden. The thesis also proposes how to use current flood information during flood emergency utilizing geographical information system. This provides spatial information for area in the flood zone for assessment regarding flood vulnerability. Using map overlay analysis in GIS software (ArcGIS); flood prone areas and topographic data along Lake Roxen and Lake Glan were digitized from PDF maps. Thus, the thesis work is an effort to analyze impact of flood when areas along Lake Roxen and Lake Glan are flooded. ESRI® GIS software Arc Map 9 and Arc View 3.3 is used for data preparation, integrating, analyzing, and spatial data with attribute table information. Finally, to show GIS can be an effective tool for development of flood emergency system as a part of disaster preparedness by the decision makers.