Search for dissertations about: "Per-Erik Jansson"

Showing result 6 - 10 of 24 swedish dissertations containing the words Per-Erik Jansson.

2. 6. Environmental Modelling : Learning from Uncertainty

   Author : John M. Juston; Per-Erik Jansson; Jens Christian Refsgaard; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Models; data; error; uncertainty; hydrology; soil carbon; wetlands; phosphorus;

   Abstract : Environmental models are important tools; however uncertainty is pervasive in the modeling process.   Current research has shown that under­standing and representing these uncertainties is critical when decisions are expected to be made from the modeling results. READ MORE

4. 7. Water and Carbon Balance Modeling: Methods of Uncertainty Analysis

   Author : John Juston; Per-Erik Jansson; Georg Lindgren; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Modeling; uncertainty analysis; water balance; carbon balance; GLUE; Environmental engineering; Miljöteknik;

   Abstract : How do additional data of the same and/or different type contribute to reducing model parameter and predictive uncertainties? This was the question addressed with two models – the HBV hydrological water balance model and the ICBM soil carbon balance model – that were used to investigate the usefulness of the Generalized Likelihood Uncertainty Estimation (GLUE) method for calibrations and uncertainty analyses.  The GLUE method is based on threshold screening of Monte Carlo simulations using so-called informal likelihood measures and subjective acceptance criterion. READ MORE

5. 8. Irrigation with saline water using low-cost drip-irrigation systems in sub-Saharan Africa

   Author : Louise Karlberg; Per-Erik Jansson; Reinder Feddes; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; Water use efficiency; Radiation use efficiency; Management techniques; Modelling; Tomato; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

   Abstract : In the scope of future population support, agricultural productivity, in particular in sub-Saharan Africa, has to increase drastically to meet the UN’s millennium development goals of eradicating extreme poverty and hunger by 2015. Water availability in the root-zone limits crop production in large parts of the developing world. READ MORE

6. 9. Monitoring transport and fate of de-icing salt in the roadside environment : Modelling and field measurements

   Author : Annika Lundmark; Per-Erik Jansson; Bo Olofsson; Ann-Catrine Norrström; Helen K. French; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chloride; De-icing salt; Groundwater; Modelling; Monitoring; Road; Roadside; Soil water; Water in nature and society; Vatten i natur och samhälle;

   Abstract : Roads and traffic are a major non-point source of pollutants and may have severe impacts on surface water, groundwater, soil and vegetation. In cold climates, de-icing salt is one such pollutant that may cause increased chloride concentrations and induce other effects on the environment. READ MORE

7. 10. Road disasters? Modeling and assessment of Swedish roads within crucial climate conditions

   Author : Alireza Nickman; Bo Olofsson; Per-Erik Jansson; Nils-Otto Kitterød; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Road; Flood; Moisture; Temperature; Groundwater; GIS; Uncertainity; Sweden; Mark- och vattenteknik; Land and Water Resources Engineering;

   Abstract : An efficient maintenance of roads to ensure high accessibility and durability of the transport capacity requires an understanding of how the hydrological response depends on both the road and the landscape characteristics. New methods and data were used to identify and explain interaction between roads and surrounding environment and their influence on hydrologic responses both in watershed scale and road-section scale. READ MORE