Yosio Edemir Shimabukuro a, b René Beuchle b Rosana Cristina Grecchi b Dario Simonetti b Frédéric Achard b

Transcription

1 Assessment of Deforestation and Forest Degradation due to Selective Logging and Fires using Time Series of Fraction Images derived from Landsat ETM+ images Yosio Edemir Shimabukuro a, b René Beuchle b Rosana Cristina Grecchi b Dario Simonetti b Frédéric Achard b a Instituto Nacional de Pesquisas Espaciais (INPE) Remote Sensing Division (DSR), São José dos Campos, Brazil b Joint Research Centre of the European Commission (JRC) Institute for Environment and Sustainability (IES), Ispra, Italy (yosio.shimabukuro; rene.beuchle; rosana.grecchi; jrc.ec.europa.eu 1

2 OUTLINE - INTRODUCTION - STUDY AREA - MATERIAL - METHODOLOGY - RESULTS - CONCLUSIONS 2

3 SELECTIVE LOGGING INTRODUCTION Forest degradation is a key process for the UNFCCC REDD+ mechanism (Reduction of Emissions from Deforestation and forest Degradation) Forest degradation in the Brazilian Amazon is mainly due to selective logging and forest fires FOREST FIRE 3

4 OBJECTIVES The main objective of this work is to develop a semi-automated procedure based on fraction images for the assessment of forest degradation caused by selective logging and forest fires in the Brazilian Amazon using a Landsat time series dataset. 4

5 Study Area Landsat ETM+ 15 Jun Jul Jul Aug Aug Sep Sep Oct 2002 The study area corresponds to one Landsat scene (path/row 227/068) located in the State of Mato Grosso, in the region named Deforestation Arc of the Brazilian Amazon 150 km 5 Sentinel-2 For Science Workshop, May 2014 ESA-ESRIN Frascati (Rome) Italy

6 METHOD The proposed method is performed according to the following steps: - to generate a forest mask to prevent mapping areas already deforested before 2002; - to generate fraction images for all 2002 ETM+ images selected for this study; - to apply the image segmentation process to a multi-temporal dataset composed of soil and shade fraction images derived from ETM+ time series; - to generate map of selective logging and deforested areas for all analyzed soil fraction images; - to generate map of burned areas for all analyzed shade fraction images; - to combine the resulting two maps to generate the degradation forest areas due to selective logging and due to forest fire. 6

7 METHODOLOGICAL APPROACH 7

8 Fraction images enhance: Shade: forest canopy structure, water, and burned areas ETM+ 05 October 2002 Selective Logging Soil: bare soil, deforestation, and other non-photosynthetic materials Burned Clear cut Soil Fraction Image Vegetation: forest canopy, regrowth areas Shade Fraction Image 8

9 ETM+ 02 OCT 2001 DEFORESTATION MAP - INPE PRODES

10 ETM+ 15 June 2002 Mapping new deforested areas 10

11 ETM+ 15 June 2002 Mapping burned areas 11

12 ETM Map of deforested areas ETM Map of burned and deforested areas 12

13 Forest degradation by fires 13

14 ETM Mapping selective logging areas ETM+ 17 July 2002 Soil Fraction Image 14

15 15

16 Estimated areas for the mapped classes in the study area CLASSES Old Deforestation Deforestation 2002 Degradation-logging Degradation-burning Forest Water AREA (km2) 6, (*) , Total 25,066 (*) Forest degradation due to selective logging is overestimated for the year 2002 since we have not masked the previous selective logging areas 16

17 CONCLUSIONS - Forest mask is essential for developing a procedure for detecting and mapping forest degradation areas. - Forest degradation due to selective logging can be detected and mapped using soil fraction images. - Forest degradation due to fires can only be mapped using time series images because burned areas can also be related to deforestation process when burning is used to clear the remaining vegetation. - The proposed method shows the potential to discriminate selective logging from burned forests within degraded forests, which is very important for estimation of carbon emissions. - The future availability of time series of high spatial resolution data (Sentinel-2) is expected to improve the assessment of deforestation and forest degradation processes and consequently facilitate implementing actions to protect the forest lands. 17

18 Thank you for your attention 18