Two small bordering catchments in Bispgården, Central Sweden, wereinvestigated in regard to soil solution and stream water chemistry during the frostfree seasons of 2003-2007. Both catchments were drained by first order streams,Fanbergsbäcken and Gråbergsbäcken, and in Fanbergsbäckens catchment anextensive investigation of the soil and soil solution chemistry was conducted bylysimeter and centrifugation sampling. The area of intensive soil solutioninvestigation was situated in a slope towards a stream incorporating a rechargearea, with podzolic soil, and a discharge area close to the stream with an arenosolsoil. Samples were continuously taken in both the recharge- and the discharge areaof the slope, and stream water was sampled in the streams of both catchments. Themain variables of interest of the study were the interactions, the influence ofdissolved organic carbon and the effects of wood ash application to soil solutionand stream water.The natural variations and the interactions between soil solution and streamwater were monitored during 2003-2004. In soil solution, most of the investigatedsubstances tended to increase during the growing season, due to weathering andmicrobial degradation of biota. Ca, Mg, Al and Fe were highly associated todissolved organic carbon (DOC) throughout the catchment. The low molecularfraction of DOC seemed to have a higher impact on the soil processes in therecharge area, while high molecular DOC was more important for transport ofcations in the discharge area and the stream water.The concentration of different substances in the two streams differedsignificantly, even though the catchments were similar in size, shape andforestation. The seasonal patterns of most of the substances measured weresignificantly correlated between the streams, however. Cations and pH correlatedwell with DOC and flow. The flow pattern driven by precipitation seems to be thedriver of the stream water chemistry.Wood ash was applied at a dosage of 3 ton/ha to one of the catchments in theautumn of 2004, to investigate the initial effects on the soil solution- and streamwater chemistry. WAA is recommended by the Swedish Forest Agency tocounteract acidification in soil and runoff that may be caused by an intensivebiomass harvesting. The impact of the WAA was studied during 2005-2006.Compared to the control temporarily higher concentrations of K, Ca and SO4 wereobserved in the soil solution of the ashed area. In the stream water the effects of theWAA were easier to distinguish due to higher sampling frequency. The strongesteffect was seen for K, but increases in the stream water were also noted for DOC,Ca, Mg, Si, Cl and malonate. No increase in pH could be statistically verifiedhowever, and overall the initial effects of the WAA seem mild. / Två angränsande avrinningsområden i Bispgården i centrala Sverigeundersöktes under den snöfria säsongen 2003-2006. Båda avrinningsområdenadränerades av första ordningens bäckar och i det ena, Fanbergsbäckensavrinningsområde, gjordes en omfattande undersökning av mark och markvattenkemin.Markvatten provtogs genom centrifugering och med lysimetrar.Provtagningen gjordes i inströmningsområdet där jordmånen var en typiskpodzol samt närmare bäcken, i utströmningsområdet, där jordmånen var enarenosol. Bäckvatten provtogs i båda avrinningsområdena. Interaktioner mellanmark, markvatten och bäckvatten undersöktes med särskilt fokus på inverkan avorganiskt kol samt påverkan av askåterföring.De naturliga variationerna i markkemin samt interaktionerna mellan mark- ochbäck vatten undersöktes 2003-2004. I markvatten ökade merparten av de studeradeämnena under provtagningssäsongen beroende av ökad vittring och recirkulationav biota och fallförna. Ca, Al och Fe var i stor utsträckning associerade till löstorganiskt kol (DOC). Den lågmolekylära fraktionen av DOC hade en störreinverkan på markprocesserna i inströmningsområdet, medan den högmolekyläradelen var viktigare för transport av katjoner i utströmningsområdet samt ibäckvattnet.Koncentrationsnivåerna av olika substanser i bäckarna uppvisade skillnadertrots avrinningsområdenas yttre likheter med avseende på storlek, form ochbeskogning. Trots de kvantitativa skillnaderna erhölls emellertid liknandesäsongsvariationer i koncentrationerna, vilket indikerade att kemin i huvudsakstyrdes av mängden DOC som i sin tur berodde av avrinningen som drevs avnederbörden. Höga halter av Ca, Mg, Al och Fe återfanns associerade tillhögmolekylärt DOC i bäckvattnet i en utsträckning som inte rapporterats tidigare.På hösten 2004 spreds 3 ton aska/ha till Fanbergsbäckens avrinningsområde föratt undersöka de initiala effekterna på mark- och bäckvatten kemin. Askåterföringbör ske minst en gång per omloppstid vid helträdsavverkning, i enlighet medSkogsstyrelsens rekommendationer, främst för att motverka försurning i mark ochavrinnande vatten som antas uppstå vid intensivt uttag av biomassa. De initialaeffekterna av askåterföringen på mark- och bäckvattnets kemi studerades under2005-2006 och Gråbergsbäcken kunde användas som obehandlad kontroll vidundersökning av vattenkemin i Fanbergsbäcken. I undersökningen av markvattenviåterfanns stora säsongsvariationer, vilket gjorde det svårt att urskilja eventuellaeffekter av askåterföringen. Tillfälligt högre värden av K, Ca och SO4 återfannsdock i det askade området i jämförelse med kontrollområdet. På grund av högreprovtagningsfrekvens i bäckvattnet var det lättare att påvisa förändringar ibäckvatten kemin. Framförallt märktes en signifikant ökning av K jämfört medkontrollbäcken. Sådana ökningar, om än inte lika markanta återfanns också förDOC, Ca, Mg, Si, Cl och malonat. En tendens till ökat pH kunde observeras, mendenna kunde inte verifieras statistiskt. De initiala effekterna av askåterföringen varsåledes till synes milda, och den eftertraktade pH-effekten erhölls ej i dennaundersökning.

Hydroelectric reservoirs account for 59% of the installed electricity generating capacity in Canada and 26% in Ontario. Reservoirs also provide irrigation capacity, drinking water, and recreational opportunities. Further, they continue to be built in northern Canada, neighbouring boreal countries, and around the world. Yet given their socio-economic importance, they are understudied with respect to greenhouse gas emissions, nutrient and mercury cycling, and aquatic metabolism. As one of many electricity generating options, hydroelectricity is viewed as well-tested because of its long history and diverse applications in mega-projects, run-of-the-river dams, and small, local applications. It is also considered renewable from a fuel stand-point because an adequate long-term supply of water is assumed. One of several significant criticisms of hydroelectric development is that reservoirs may be a significant source of greenhouse gases to the atmosphere relative to the amount of electricity produced due to flooding the landscape. As a result of the dearth of information on reservoir development and both greenhouse gases and aquatic metabolism, a pair of whole-ecosystem reservoir experiments were conducted staring in 1991. Three upland boreal forest reservoirs with differing amounts of pre-flood stored organic carbon were built in northwestern Ontario and flooded for five years. The rates of net greenhouse gas production in these reservoirs were determined by calculating mass budgets for carbon dioxide and methane. Additionally, rates of biological processes were determined by combining the mass budgets with measurements of the stable isotopes of carbon and oxygen. Assembling mass and isotope-mass budgets required three related projects on gas exchange, methane oxidation, and oxygen isotopes. To estimate the gas exchange coefficient for each of the upland reservoirs, a comparative-methods study was undertaken. Methane oxidation enrichment factors were determined in upland and wetland boreal reservoirs so that the importance of methane oxidation in these ecosystems could be assessed. In order to interpret the diel changes in both oxygen concentrations and their isotopic ratios, a dynamic model was developed. This model, PoRGy, was successfully applied to the upland boreal reservoirs as well as prairie rivers and ponds. Further, PoRGy was used to understand the interplay between the key parameters that control oxygen concentrations, to compare aquatic ecosystems, to make quantitative estimates of ecosystem metabolism, and to assess the vulnerability of aquatic ecosystems under various environmental stressors. Carbon isotope-mass budgets were used to conclude that community respiration rates declined quickly in the upland reservoirs and had declined by half over five years. This suggested that the most labile organic carbon is quickly consumed but decomposition continued for the five-year life of the project. Net primary production rates were similar for three years, with a small peak in the second or third year, before declining by half by the fifth year. Together, these results indicated that aquatic metabolism slowed over five years while the reservoirs remained a source of greenhouse gases to the atmosphere each year. Net methane production was greatest in the third year of flooding then decreasing by about half by the fifth year. Methane ebullition also peaked in the third year and declined by two-thirds by the fifth year. Together, these results indicated that methanogenesis was greatest in the third year of flooding. The flux of methane to the atmosphere grew in importance relative to that of carbon dioxide over the five years of the experiment. Community respiration and primary production could not be estimated directly from the oxygen isotope-mass budgets since the oxygen respiration enrichment factor remains poorly constrained. Instead, three estimates were made, each based on a different assumption. In general, these estimates suggested that rates of community respiration and primary production decreased slightly for three years and most rapidly in the final two years. The oxygen isotope-mass budgets provided a new method for assessing and constraining community metabolism and greenhouse gas fluxes to the atmosphere. One of the major hypotheses of the whole-ecosystem reservoir experiments was that pre-flood organic carbon stores less tree boles were positively related to greenhouse gas fluxes. Within the three upland boreal forest reservoirs, this hypothesis did not hold true. Over five years, community respiration in the three reservoirs was within 5% of each other. When methane is included, to assess total greenhouse gas fluxes to the atmosphere, the reservoirs were within 1% of each other. Organic carbon stores were therefore poor short-term predictors of carbon lability and greenhouse gas fluxes. This research presented two methods for determining biological rates at the whole-ecosystem scale: one using carbon isotopes and one using oxygen isotopes. Temporal evolution of greenhouse gas cycling within the upland reservoirs was different than in the wetland reservoir and should inform how reservoir development is done vis-à-vis the amount of flooded land of each type versus electricity production. Medium-term estimates of greenhouse gas fluxes suggest that upland reservoirs do not have adequate pre-flood organic carbon stores to sustain elevated levels of decomposition the way wetlands do. The strong evidence of continued production of dissolved organic carbon in the upland reservoirs should concern operators of municipal drinking water reservoirs since elevated dissolved organic carbon can make disinfection difficult.

There is a great need to reduce nutrient leaching from arable land into lakes and oceans. By using several different types of models it has previously been possible to describe nutrient losses in a catchment area with a minimum unit of sub-catchment level. At present, it is instead desirable to model a smaller catchment with an opportunity to re-connect the results to the corresponding fields in the catchment. Such models already exist but they are not fully able to properly describe Swedish conditions and land characteristics in our region. With the approach of creating such a model, SLU has developed a project with this work as its first stage. The model is expected to be created under the working name SWE-model which stands for Soil Water Environment and is in this first stage supposed to apply the SOIL model in catchment scale. During the procedure to describe the first step in the process of developing such a model adapted to Swedish conditions and which works in the catchment scale with an area of about 10-30 km2, focus has been set on calculating the transport of water flow from different hydrological response units. Regardless of the processes occurring in the soil after the water has been added, it is assumed that all the water which flows from each simulated unit is drained. In the first step the hydrologic response units were identified based on land use and soil type in the study area. With the help of a script with functions that retrieve and transform data, certain units were chosen for simulation. The script was also created in this project. Finally, the model results were aggregated and summarized for each unique unit, for each sub-catchment, and also for the whole catchment. From the results it is possible to see similarities in the flow dynamics between modeled and measured data. The efficiency coefficient has been calculated to correspond to the mean of the measured values for the whole simulation period. With an automated calibration process the model should be able to perform better. The volume error gives an indication of overestimation from the model.

High pressure on water from competing users has changed the past perception of water as gift to water as a resource that requires sustainable management. Management of water resource needs active stakeholders’ involvement for its sustainability. Many organizations along with the national water policy have been calling for active stakeholders’ involvement for management of the resource.  In Usangu catchment conflicts over accessing water between farmers and pastoralists and between upstream and downstream have been common. Water allocation in the catchment has been done without involving stakeholders and adequate consideration of the rivers’ carrying capacity. This study focuses on stakeholders’ involvement in Usangu catchment. Six villages in three sub-catchments were studied and data were collected using questionnaire through face to face interview and focus group discussion. The study found that there is limited stakeholders’ involvement in Usangu catchment. In some places involvement is at basic stage, in other places there is no involvement. Interaction within stakeholders’ category was documented, while no stakeholders’ interaction between sub-catchments was discovered. Moreover, some challenges for active involvement were noted, such as lack of coordination between institutions operating in the catchment, high illiteracy rate and lack of awareness, and with lack of legislation support. The issue of limited stakeholders’ involvement in Usangu catchment is complicated, there is no single and comprehensive solution; integration of different approaches which are cross-sectoral in nature is needed for sustainable water management.

Hydroelectric reservoirs account for 59% of the installed electricity generating capacity in Canada and 26% in Ontario. Reservoirs also provide irrigation capacity, drinking water, and recreational opportunities. Further, they continue to be built in northern Canada, neighbouring boreal countries, and around the world. Yet given their socio-economic importance, they are understudied with respect to greenhouse gas emissions, nutrient and mercury cycling, and aquatic metabolism. As one of many electricity generating options, hydroelectricity is viewed as well-tested because of its long history and diverse applications in mega-projects, run-of-the-river dams, and small, local applications. It is also considered renewable from a fuel stand-point because an adequate long-term supply of water is assumed. One of several significant criticisms of hydroelectric development is that reservoirs may be a significant source of greenhouse gases to the atmosphere relative to the amount of electricity produced due to flooding the landscape. As a result of the dearth of information on reservoir development and both greenhouse gases and aquatic metabolism, a pair of whole-ecosystem reservoir experiments were conducted staring in 1991. Three upland boreal forest reservoirs with differing amounts of pre-flood stored organic carbon were built in northwestern Ontario and flooded for five years. The rates of net greenhouse gas production in these reservoirs were determined by calculating mass budgets for carbon dioxide and methane. Additionally, rates of biological processes were determined by combining the mass budgets with measurements of the stable isotopes of carbon and oxygen. Assembling mass and isotope-mass budgets required three related projects on gas exchange, methane oxidation, and oxygen isotopes. To estimate the gas exchange coefficient for each of the upland reservoirs, a comparative-methods study was undertaken. Methane oxidation enrichment factors were determined in upland and wetland boreal reservoirs so that the importance of methane oxidation in these ecosystems could be assessed. In order to interpret the diel changes in both oxygen concentrations and their isotopic ratios, a dynamic model was developed. This model, PoRGy, was successfully applied to the upland boreal reservoirs as well as prairie rivers and ponds. Further, PoRGy was used to understand the interplay between the key parameters that control oxygen concentrations, to compare aquatic ecosystems, to make quantitative estimates of ecosystem metabolism, and to assess the vulnerability of aquatic ecosystems under various environmental stressors. Carbon isotope-mass budgets were used to conclude that community respiration rates declined quickly in the upland reservoirs and had declined by half over five years. This suggested that the most labile organic carbon is quickly consumed but decomposition continued for the five-year life of the project. Net primary production rates were similar for three years, with a small peak in the second or third year, before declining by half by the fifth year. Together, these results indicated that aquatic metabolism slowed over five years while the reservoirs remained a source of greenhouse gases to the atmosphere each year. Net methane production was greatest in the third year of flooding then decreasing by about half by the fifth year. Methane ebullition also peaked in the third year and declined by two-thirds by the fifth year. Together, these results indicated that methanogenesis was greatest in the third year of flooding. The flux of methane to the atmosphere grew in importance relative to that of carbon dioxide over the five years of the experiment. Community respiration and primary production could not be estimated directly from the oxygen isotope-mass budgets since the oxygen respiration enrichment factor remains poorly constrained. Instead, three estimates were made, each based on a different assumption. In general, these estimates suggested that rates of community respiration and primary production decreased slightly for three years and most rapidly in the final two years. The oxygen isotope-mass budgets provided a new method for assessing and constraining community metabolism and greenhouse gas fluxes to the atmosphere. One of the major hypotheses of the whole-ecosystem reservoir experiments was that pre-flood organic carbon stores less tree boles were positively related to greenhouse gas fluxes. Within the three upland boreal forest reservoirs, this hypothesis did not hold true. Over five years, community respiration in the three reservoirs was within 5% of each other. When methane is included, to assess total greenhouse gas fluxes to the atmosphere, the reservoirs were within 1% of each other. Organic carbon stores were therefore poor short-term predictors of carbon lability and greenhouse gas fluxes. This research presented two methods for determining biological rates at the whole-ecosystem scale: one using carbon isotopes and one using oxygen isotopes. Temporal evolution of greenhouse gas cycling within the upland reservoirs was different than in the wetland reservoir and should inform how reservoir development is done vis-à-vis the amount of flooded land of each type versus electricity production. Medium-term estimates of greenhouse gas fluxes suggest that upland reservoirs do not have adequate pre-flood organic carbon stores to sustain elevated levels of decomposition the way wetlands do. The strong evidence of continued production of dissolved organic carbon in the upland reservoirs should concern operators of municipal drinking water reservoirs since elevated dissolved organic carbon can make disinfection difficult.

Because of climate change and resource development there is an ongoing increase in the attention directed towards high latitude areas. Over the last years, warming in the Arctic has accelerated quickly. The warming climate can possibly lead to thawing of ground ice, which in turn leads to alterations of the cryosphere. This can have a huge influence on the terrestrial hydrology of the Arctic and, more specifically, on the presence and distribution of lakes in arctic regions since both are coupled to subsurface ice. In this thesis data from remote sensing were used to look at the change in the size distribution of lakes for the Nadym catchment in northern Russia. The aim was to find out if there has been an increase or decrease in the number of lakes in the area over the past years. Results suggest that there were 229 lakes less (representing a 4% decrease) in 2007–2009 compared to 1987, indicating that lakes are slowly disappearing. Also, the total lake surface area decreased with 5%. Almost half of the lakes that disappeared (49%) can be found among the smallest lakes ranging between 10–20 ha. In the entire catchment this size class was also found to be the class with by far the highest number of lakes.

<p>A road in operation along with its traffic can pose aserious pollutant threat to groundwater and surface water inits vicinity. Examples of pollutants are metals from thecorrosion of vehicles, rails and poles and the wear of roadsurfaces and tyres; hydrocarbons from the wear of roadsurfaces, tyres, exhausts, oils; sodium chloride from roadsalt; and hazardous goods discharged in accidents. Eventuallypollutants that are not degraded or retarded in soil will reachgroundwater and surface water. The chloride ion in deicing saltis a good tracer. It is conservative and highly soluble and notsubject to retardation or degradation. If the chlorideconcentration has increased in groundwater or surface water inthe vicinity of a deiced road, other road-related pollutantsmight also be present in the water.</p><p>Increased chloride concentrations have been observed inseveral water supplies, in groundwater as well as in surfacewater, since the 1970s. The number of affected water supplieshas also increased. The increase in chloride concentration inwaters is concurrent with the increase in deicing saltapplication and it is clear that most of the increase is due tothe application of deicing salt.</p><p>The thesis presents a simple tool that quantified theincrease in chloride concentration for water in a catchmentarea, based on a steady-state water balance. The data wereefficiently processed and presented as maps with GIS. At aregional catchment area scale, substantially increased chlorideconcentrations were calculated. The variation between catchmentareas was verified by a national monitoring programme of lakes.Deicing salt application was estimated to account for more thanhalf of the total chloride load for a catchment area in the midsouth of Sweden.</p><p>A distributed dynamic method was used to evaluate thetemporal and spatial variation of the chloride concentration inan aquifer. The distributed dynamic approach integrated thespreading of deicing salt from the road with the infiltrationin the unsaturated zone in the soil, which in turn wasintegrated with the groundwater flow. The simulation was runfor a 40-year period and showed a potential to describe aspecific system.</p><p><b>Keywords:</b>road, deicing salt, monitoring, chloride,catchment area, river basin, simulation, GIS, groundwater,surface water</p>

<p><p>Chlorine is an element commonly found in the environment of our planet, in the atmosphere, the earth crust and the oceans. Chlorine occurs in two forms, inorganic chloride (Cl_in) and organically bound chlorine (Cl_org), also called organochlorine. For a long time, the organic halogens (among them the organic chlorine) had been considered as produced only by human activities. However, the research of the recent decades suggests a considerably amount of naturally produced organic chlorine in soil and water. Through the research, a hypothesis have emerged, suggesting that there occur a formation of organic chlorine in the top soil layer where chloride is consuming, while the organic chlorine is degrading on deeper soil levels, causing a release of chloride. The study in this thesis attempts to explore the transportation of organic chlorine through soil. 49 soil water samples were collected at three transects, S04, S12 and S22, nearby a stream in northern Sweden and analysed for Cl_org, using an AOX-analyser. The results suggest a decrease in concentrations of Cl_org by soil depth for transects S04 and S12. The study also indicates that concentrations of Cl_org are decreasing with increasing distance from the stream, where the highest mean concentration was found in the organic matter-rich riparian transect S04. Further conclusions are that the spring flood and changes in groundwater level may influence the concentrations of Cl_org.</p></p> / <p><p>Ämnet klor är vanligt förekommande på vår planet och finns både i atmosfären, jordskorpan och världens oceaner. Klor uppträder i två olika former: oorganisk klorid (Cl_in) och organiskt bundet klor (Cl_org). De organiska halogenerna (bland vilka organiskt klor ingår) har under lång tid ansetts härstamma från enbart antropogena källor. De senaste decenniernas forskning har dock tytt på en naturlig produktion av organiskt klor i mark och vatten. Genom denna forskning har en hypotes tagit form som föreslår en bildning av organiskt klor i de övre marklagren, där klorid binds, medan det i djupare marklager sker en nedbrytning av det organiska kloret vilket medför ett frigörande av klorid. Denna studie syftar till att studera transporten av organiskt klor genom mark. 49 stycken markvattenprover insamlades vid tre provpunkter (S04, S12 och S22) på ett avrinningsområde i norra Sverige och analyserades med hjälp av ett AOX-instrument. Resultaten tyder på en minskning av Cl_org med ökande markdjup för provpunkterna S04 och S12. Studien visar även en minskning i koncentration av organiskt klor med ökande avstånd till vattendraget, där den högsta medelkoncentrationen återfanns i provpunkten S04 som ligger nära bäcken och är rik på organiskt material. Vidare slutsater är att vattenflödena under vårflod samt variasionen i grundvattennivå har en påverkan på koncentrationerna av Cl_org.</p></p>

Inverse geochemical modelling has been used frequently in groundwater systems between wells along a known flowpath and between precipitation and stream waters in catchments. This research expands the use of inverse geochemical modelling through a reaction path model (RPM) between waters in an alpine catchment to determine the geochemical connections and disconnections within the catchment. The data for this study are from the Green Lake 4 catchment in the Colorado Front Range during the 1996 snowmelt season, which has been divided into discrete time intervals based on snowmelt hydrology. Unique combinations of geochemical connections occur during these time intervals, and they show a dynamic hydrologic system. RPM results show notable disconnections; soil water is not geochemically connected to any other end member. These changes reflect changes in weathering reactions in the catchment that are dependent on the duration and timing of snowmelt. Previously end-member mixture analysis (EMMA) models have been used to discern the water sources in catchments. The combination of RPM and EMMA approaches offers the opportunity to connect the source of water to the internal hydrologic structure of the catchment, to better understand how catchments might respond to changes in climate or atmospheric deposition.

Quantifying carbon emissions of water bodies at regional scale is required as recent studies revealed their contribution in carbon cycling is significant. This demands to scale up water bodies carbon emissions from local to regional scale using as accurate approach as possible. In this study data of carbon (CO2-C) fluxes for 80 sampled lakes were used to scale up to more than 3000 lakes and ponds over the catchment. The most appropriate method for upscaling was the one in which two factors of water body size and location (altitude) were involved and the uncertainties were quantified in an advanced approach (Monte Carlo model). Based on the estimates obtained in this method, the annual carbon emission from all water bodies (~ 500 km2) was about 2900 ton C yr-1 . About 62% of this annual emission was related to the large lake Torneträsk (334 km2) and another 38% to all other lakes and ponds (166 km2). Water bodies in subalpine region dominated (90%) total water bodies area and were the major contributor (97%) to the total carbon emissions of all water bodies. The remaining small contribution (3%) was for water bodies in the alpine region, which contains only 10% of total water bodies area. These data indicate that all water bodies smaller than the large lake Torneträsk especially the ones in the subalpine region have considerable contribution to the annual carbon emission of all water bodies. Considering water body size and altitude factors in the advanced upscaling method was appropriate to obtain accurate estimates.