Avancerad sökning

Visar resultat 1 - 5 av 104 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Catching Mercury : Mercury in Lake Vänern and Swedish catchments

   Författare :Peter Wihlborg; Lars Hylander; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mercury; deposition; budget; sediments; retention; catchments; dating; kvicksilver; deposition; budget; retention; avrinningsområden; datering; Water in nature and society; Vatten i natur och samhälle;

   Sammanfattning : Vänern och dess sediment har under 1900-talet varit en av Sveriges mest kvicksilver (Hg) kontaminerade miljöer. 47 sedimentprofiler tagna 2001 analyserades for total Hg och temporala och spatiala mönster påvisades. Av den direkta Hg tillförseln 1918-2001 återfinns c:a 30 ton i bottensedimenten. LÄS MER

3. 2. Hydrogeochemistry of Fe and Mn in small boreal catchments

   Författare :Louise Björkvald; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hydrogeochemistry; Fe; Mn; boreal catchments; spring flood; Other earth sciences; Övrig geovetenskap;

   Sammanfattning : It is suggested that the overall understanding of the general hydrogeochemistry of a region is best understood from a landscape perspective. If so, this can provide useful information when planning monitoring programmes and influence of human activity. LÄS MER

4. 3. Hydrological Transport in Shallow Catchments: : tracer discharge, travel time and water age

   Författare :Sofie Safeyeh Soltani; Vladimir Cvetkovic; Bijan Dargahi; Jan Olof Selroos; Andrea Rinaldo; KTH; []
   Nyckelord :Hydrological transport; travel time; water age; tracer discharge; Lagrangian pathway approach; pathway lengths; numerical modeling; Land and Water Resources Engineering; Mark- och vattenteknik;

   Sammanfattning : This focuses on hydrological transport in shallow catchments with topography-driven flow paths. The thesis gives new insight to kinematic pathway models for estimation of tracer discharge at the catchment outlet. LÄS MER

5. 4. Long-term development, modeling and management of nutrient loading to inland and coastal waters

   Författare :Amelie Darracq; Georgia Destouni; Andrea Rinaldo; Stockholms universitet; []
   Nyckelord :Nutrients; catchments; environmental management; climate change; population and lifestyle development; subsurface-surface water interactions; long-term simulations; nutrient retention; modeling; hydrology; transport processes; biogeochemistry; scaling; transport and reaction rates; Physical Geography; geografi med naturgeografisk inriktning;

   Sammanfattning : Environmental and water system protection and restoration require accurate knowledge and quantification of waterborne pollutant transport, retention-release and transformation processes taking place in the subsurface, river, lake and sea water systems, and at the interfaces between these systems. This thesis investigates the importance of spatial model resolution for such quantification and the possible long-term nutrient load development under different human perturbations and nutrient source management scenarios in the Swedish Norrström drainage basin, based on simulations with the GIS-based dynamic nutrient transport-attenuation model POLFLOW. LÄS MER

7. 5. Water quality modeling based on landscape analysis: importance of riparian hydrology

   Författare :Thomas Grabs; Jan Seibert; Kevin Bishop; Hjalmar Laudon; Brian McGlynn; Georgia Destouni; Irena Creed; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Water quality model; terrain analysis; geographical information system GIS; riparian zone; total organic carbon TOC; boreal catchments; Hydrology; Hydrologi; geografi med naturgeografisk inriktning; Physical Geography;

   Sammanfattning : Several studies in high-latitude catchments have demonstrated the importance of near-stream riparian zones as hydrogeochemical hotspots with a substantial influence on stream chemistry. An adequate representation of the spatial variability of riparian-zone processes and characteristics is the key for modeling spatio-temporal variations of stream-water quality. LÄS MER