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- Andersson, Lotta, 1958-
(författare)
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Annual variability of nitrogen concentrations and export from forested catchments : A consequence of climatic variability, sampling strategies or human interference?
- 2000
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Ingår i: Boreal environment research. - 1239-6095 .- 1797-2469. ; 5:3, s. 221-233
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Tidskriftsartikel (refereegranskat)abstract
- This study was based on the data from 18 years of monitoring in six forested catchments. The aim was to find links between annual estimates of export and concentrations of NO3-N and organic N and hydroclimatological factors, sampling strategy and human interference. A topography-based wetness index was used to assess whether the effects of forestry activities depended on prevailing wetness conditions. For organic N, annual runoff was the main explaining factor in three catchments. The flow condition during sampling was for organic N the main explaining factor in three and for NO3-N in one catchment. Effects of clear-cutting of 14% in one catchment were observed. For organic N, the model could be improved by considering clear-cutting in wet areas only. The southernmost catchment, but also the northernmost catchment with the lowest deposition, showed links to atmospheric deposition, demonstrating that deposition can cause a significant direct response in streamwater concentrations in nutrient-poor catchments.
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| 2. |
- Andersson, Lotta, 1958-, et al.
(författare)
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Assessment of climate change impact on water resources in the Pungwe river basin.
- 2011
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Ingår i: Tellus. Series A, Dynamic meteorology and oceanography. - : Stockholm University Press. - 0280-6495 .- 1600-0870. ; 63:1, s. 138-157
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Tidskriftsartikel (refereegranskat)abstract
- The Rossby Centre Regional Climate Model (RCA3) and the hydrological model HBV were linked to assess climate change impacts on water resources in the Pungwe basin until 2050. RCA3 was capable of simulating the most important aspects of the climate for a control period at the regional scale. At the subbasin scale, additional scalingwas needed. Three climate change experiments using ECHAM4-A2, B2 and CCSM3-B2 as input to RCA3 were carried out. According to the simulations annual rainfall in 2050 would be reduced by approximately 10% with increasing interannual variability of rainfall and dry season river flow and later onset of the rainy season. The ECHAM4-A2 driven experiment did also indicate a slight increase of high flows. If the results indeed reflect the future, they will worsen the already critical situation for water resources, regarding both floods and droughts. Uncertainties, however in the downscaled scenarios make it difficult to prioritize adaptation options. This calls for inclusion of more climate change experiments, in an ensemble of climate scenarios possibly by using a combination of dynamical and statistical downscaling of general circulation models, as well as extending the simulations to 2100 to further ensure robustness of the signal.
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| 3. |
- Andersson, Lotta, 1958-
(författare)
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Ecohydrological water flow analysis of a Swedish landscape in a 100 year perspective
- 1989
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The study basically involves analysis in a 100 year perspective of the hydrological response on precipitation from different landscape elements in south-central Sweden, characterized by the interaction of topography, soil type, land management and canopy cover.For this purpose, a dynamic water partitioning model, based on the soil moisture balance, was developed together with a Geographical Information System (GIS)-supported method for the detection of the spatial distribution of soil wetness as an indicator of the probability to act as discharge or recharge areas respectively.A comparison was made of the performance of water balance models of various complexity. It was shown that, generally, increasing the complexity of the submodels did not improve the agreement with measured soil moisture dynamics. As an example, due to negative feedbacks, the rather conservative nature of transpiration was well described by using 30 years monthly means of potential evapotranspiration. However, two important physical processes that are often neglected in water balance models had to be included: the limitation of transpiration by low soil and air temperatures in spring and early summer, and the drainage of rainwater through unsaturated forest soils.The model was used to analyze main differences in hydrological response between forests and open grasslands. It was also used to analyze interannual fluctuations of soil moisture deficts. Ironically, the variability was never as high as in the beginning of the hydrological year. The study revealed considerable fluctuations of 10, 30 and 50-year mean soil moisture deficits, and a general secular trend towards higher summer deficits and larger fluctuations around the median. In the light of the detected critical importance of the choice of time period, the concepts of return and standard periods were challenged. It was shown that the water balance model could be calibrated to simulate also overall basin response. Thus, simulated monthly estimates of both basin evapotranspiration and recharge rates for the Velen Representative Basin agreed well with data determined with other methods.The model was also used to simulate the integrated basin response from different parts of the landscape mosaic as determined from GIS-overlays. The obvious advantage of GIS was demonstrated. Finally, changes due to the wetness-impacting human interventions were analyzed. Since the 1870s such activities were shown to, on average, have caused a slight desiccation of the landscape, although the impacts locally could be large.
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| 4. |
- Andersson, Lotta, 1958-, et al.
(författare)
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Från global klimatforskning till lokal riskanalys och klimatanpassning : Exempel på hur man kan arbeta med lokalt deltagande, kombinerat med modeller i formulering av lokal sårbarhets och anpassningsplaner vid förändrat klimat
- 2010
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Ingår i: Klimatets krav på samhället. - Linköping : Linköping University Electronic Press. - 9789173935647 ; , s. 47-64
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Bokkapitel (populärvet., debatt m.m.)abstract
- Sverige hör troligen inte till de regioner i världen som är mest sårbara för klimatvariabilitet och förändringar. Effekter från ett förändrat klimat kommer dock med stor sannolikhet att vara märkbara även lokalt i Sverige, vilket diskuteras mer ingående i Sten Bergströms artikel. Denna artikel syftar till att bidra med erfarenheter runt hur man kan arbeta med att ta fram lokalt förankrade anpassningsstrategier. Med tanke på osäkerheter om detaljer i det framtida klimatet, kan det ibland ifrågasättas om det är rimligt att göra stora investeringar på så osäkra grunder. I detta sammanhang är det viktigt att tänka på att anpassningsstrategier för att möta framtida förändringar även gör oss bättre rustade att möta den klimatvariabilitet som vi redan lever med. Att välja rätt strategier för framtiden bör därför baseras på identifikation och fokus på de klimatrelaterade problem som vi har redan idag, med fokus på de problem som ger allvarligast effekter för olika sektorer i samhället, samt, baserad på regionalt nedskalade modellberäkningar, identifikation av sannolikheten för att dessa problem kommer att öka i framtiden. I denna artikel ges ett exempel på hur man genom aktörsamverkan kan ta fram lokala och regionala åtgärdsplaner. Samverkan har assisterats av klimat och vattenmodellerare, som i dialog med lokala aktörer tagit fram det material som behövts för att föra diskussionerna vidare. Exempel ges från ett pågående projekt i Sydafrika, men metoderna är lika relevanta i Sverige. Liknande metoder har, t.ex. använts för att ta fram en lokalt föreslagen åtgärdsplan mot övergödning i Kaggebofjärden, med medverkan från bl.a. lantbrukare, sommarstugeägare och kommuner (rapport kan beställas från lotta.andersson@smhi.se) . Dessutom beskrivs kortfattat ett nystartat INTERREG-projekt, ”Baltic Climate” som bl.a. syftar till att ge kommuner och lokala aktörer runt Östersjön möjlighet att möta klimatförändringarna på ett hållbart sätt..
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| 6. |
- Andersson, Lotta, 1958-, et al.
(författare)
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Local assessment of vulnerability to climate change impacts on water resources in the Upper Thukela River Basin, South Africa : Recommendations for Adaptation
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report originates from a project entitled Participatory Modelling for Assessment of Local Impacts of Climate Variability and Change on Water Resources (PAMO), financed by the Swedish Development Agency and Research Links cooperation (NRF and the Swedish Research Council). The project is based on interactions between stakeholders in the Mhlwazini/Bergville area of the Thukela River basin, climate and water researchers from the University of KwaZulu-Natal (Pietermaritzburg Campus) and the Swedish Meteorological and Hydrological Institute (SMHI) during a series of workshops held in 2007-2009. Between the workshops, the researcher’s compiled locally relevant climate change related information, based on requests from the workshop participants, as a basis for this adaptation plan. The aim is to provide a local assessment of vulnerability to climate change impacts on water resources and adaptation strategies. The assessment identifies existing climate-water related problems, current adaptation strategies and recommendations for future action based on likelihoods for change and the severity if such changes will occur.
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| 10. |
- Andersson, Lotta, 1958-, et al.
(författare)
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Participatory modelling for locally proposed climate change adaptation related to water and agriculture in South Africa
- 2010
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Ingår i: <em><em>Global change: Facing Risks and Threats to Water Resources</em></em>. - : International Association of Hydrological Sciences (IAHS). - 9781907161131 ; , s. 214-220
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Konferensbidrag (refereegranskat)abstract
- The participatory modelling project (PAMO) carried out in the Thukela River Basin, South Africa assessed vulnerability to climate variability and change on water resources through direct involvement of affected groups. The aim was to increase stakeholder confidence and ownership, and create a local adaptation plan. Meetings were held with three stakeholder groups: (a) government authorities, research nstitutes, NGOs, (b) commercial farmers, and (c) small-scale farmers, and complemented with interviews. Based on participants’requests, modellers compiled regionally dynamically downscaled climate change projections, as well as their hydrological consequences. The project focused on agriculture, water resources/infrastructure and biodiversity. Though many future problems were shared, their pre-conditions for dealing with these were vastly different. Knowledge transfer within and across the farming communities and with government agencies on climate change, adaptation measures, and means to procure financing and permits for measures will aid local initiatives to prepare for climate variability and change.
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