Assessing Climate Changes in Arctic Sweden and Repercussions on Sami Reindeer Husbandry and Culture: Using a MODIS Image Time Series and Key Informant Interviews Gregory N. Taff The University of Memphis Department of Earth Sciences Yang Shao The University of North Carolina at Chapel Hill Department of Geography
Research Goals • Assess recent climate changes in Northern Sweden (current study 2000 – 2006) • Understand how climate changes impact and could impact Sami reindeer husbandry and Sami culture • Future work: develop new methods for stakeholders to use GIS to help manage land sustainably in this region
Climate Change in Fennoscandia Høgda et. al (2007)* • Study area – all of Fennoscandia, 1982 – 1999 • AVHRR • Climate change assessed through changes in growing season using NDVI • Growing season was determined for each pixel by first calculating a mean NDVI (for NDVI>0) over the past 18 years. Growing season was defined to begin and end as the NDVI for the pixel passed this threshold (the mean). • This method was found to correlate well with pollen and climate data indicating growing season * Høgda, K., Karlsen, S., Tømmervik, H., “5 Changes in growing season in Fennoscandia 1982-1999”, in Arctic Alpine Ecosystems and People in a Changing Environment, Springer Berlin Heidelberg, pp. 71 – 84, 2007.
Change in Onset of Spring, 1982 - 1999Høgda et al. (2007) Fig. Change in onset of spring during the period 1982 to 1999. Position of the pollen stations (star), phenological observation points (circle), and climatic stations (cross) used in Høgda et al. study.
Change in Onset of Autumn, 1982 - 1999Høgda et al. (2007) Fig. Change in onset of autumn during the period 1982 to 1999.
Methods • Remote sensing 2000 – 2006 • Monitor annual landcover changes • MODIS vegetation cover (NDVI):16-day composite (MOD13Q) product (v 5.0). • Date of first permanent snow cover • Date of snow melt • Date of peak NDVI • Peak NDVI • Average annual NDVI • Future work: • Conduct analyses back in time using AVHRR to get longer coverage • Analyze climate data • Key Informant Interviews • In what ways have Swedish Sami reindeer herders noticed local climate changes? • How has climate change impacted and how might climate change impact Sami reindeer husbandry?
(red) (NIR) NDVI = (NIR - red) / (NIR + red)
Image Processing 1 • Water bodies and permanent snow cover masked out (pixels with negative NDVI throughout summer) • For snow cover date calculations (snow cover determined by negative NDVI): • Date of first permanent snow cover: • First date when at least 75% of study area is covered in snow (and remains covered for the winter) • Date of snow melt: • First date when less than 75% of study area is covered in snow
Image Processing 2 • Monitoring vegetation changes over time • All negative NDVI values deleted • Calculations for Peak NDVI for each year: • For each image date, all nonnegative NDVI values were averaged • Date of peak average NDVI determined for each year • Peak average NDVI recorded • Calculations for annualAverage NDVI: • For each year, an average was taken of all nonnegative NDVI values of all dates in the year
Study Area • All remote sensing analyses were conducted for: • Entire study area (Northern and North Central Sweden, east of high mountains) • Intensive Study Area (ISA) in North of Sweden (land around Övre Soppero) • Future work: study area to be defined by extent of specific Sami village lands • Large tracts of land where the reindeer herds owned by members of one “village” use throughout the year • Some “villages” extend into Norway.
Julian Days at NDVI peak values (Northern Sweden) August 1 July 1 June 1
Julian Days at NDVI peak values (ISA) Julian day August 1 July 1 June 1
Conclusions from remote sensing • Average annual NDVI increasing for • Large Sweden study area • ISA in north of Sweden • Shows a likely general warming trend, continuing the trend of elongated growing season shown by Høgda et al. (2007) • Date of first snow cover very consistent over time • Peak NDVI values, date of peak NDVI, date of snow melt • No clear trend • Not enough years of data (7 years) • Trends should be apparent when AVHRR data is processed
Significance of climate change on reindeer herding • Lichen availability: video • Future work: monitor changes in lands containing lichens • Grazing lands already in danger • Mining • Forestry • Tourism structures • Insects • Layers of ice
Sami Culture • Cultural history and reindeer husbandry as far back as 7000 years • Reindeer husbandry • Gives Sami rights to use land according to state governments • 10% of Sami herd reindeer • Small percentage now rely solely on reindeer husbandry for income • Annual reindeer herding events maintain communities/families, language and culture • Reindeer calving – spring • Ear marking – summer • Reindeer corralling - autumn • Source of pride • World heritage • Approx. 20,000 Sami • Potentially dying language and culture • Sami culture historically oppressed by Scandinavian countries • Since late 20th century, a revival of Sami cultureh • Some schools now taught in Sami language • Sami parliament – GIS mapping to show compromised Sami lands