1. No category

Characterisation of land surface phenology and land
cover for the Mekong Basin on the basis of
multitemporal and multispectral satellite data from the
MODIS Sensor
Patrick Leinenkugel
German Aerospace Center (DLR)
Vortrag > Autor > Dokumentname > Datum
Overview
Introduction and objectives
Compositing
Land surface phenology
Land cover
Subpixel land cover dynamics
Conclusion
Folie #
2 2
Slide
The Mekong Basin – Environmental Issues
Dam construction
Cash crop cultivation
images.nationalgeographic.com
North-South
Economic Corridor
Deforestation
© socialearth.org
© nigeldickinson.photoshelter.com
saigon-gpdaily.com.vn
East-West
Economic Corridor
Southern
Economic Corridor
Infrastructure development
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover Dynamics > Conclusion
Folie #
3 3
Slide
Existing Land Cover Maps for the MB
Regional specific product
Global products
Global map
products
Outdated
Focus on
forest cover
only
No regional
specific
classes
Not
covering the
entire
Mekong
Basin
JRC TREES
GlobCover
MODIS LC
Less
appropriate
for
local/basin
scale
Need for an updated, comprehensive, and regional
specific land cover map at basin scale
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover Dynamics > Conclusion
Folie #
4 4
Slide
MODIS Land Cover Dynamics
Stable Pixels 2001-2009
Stable Changes
Land Cover Type
Pixels [%] per pixel
0,4
Evergreen Broadleaf forest
80%
Grasslands
63%
0,8
Woody savannas
38%
1,3
1,4
Cropland/Natural vegetation
34%
Permanent wetlands
33%
1,8
Croplands
23%
1,8
Evergreen Needleleaf forest
22%
1,8
Mixed forest
17%
1,8
Closed shrublands
12%
2,2
Barren or sparsely vegetated
2%
2,2
Open shrublands
1%
2,3
Deciduous Needleleaf forest
0%
2,4
Deciduous Broadleaf forest
0%
2,3
Savannas
0%
2,7
Label changes not related to real
land cover dynamics!
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover Dynamics > Conclusion
Folie #
5 5
Slide
Objectives
The objectives of my thesis are:
The generation of an updated and thematic comprehensive
land cover map for the entire Mekong Basin
The detection of land cover changes in the Mekong Basin for
the period 2001-2011
The analysis of spatio-temporal patterns of detected land
cover changes in the Mekong Basin for the period 2001-2011
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover Dynamics > Conclusion
Folie #
6 6
Slide
Climatic conditions in the Mekong Basin
Daily proportions of clear observations
for the Mekong Basin in 2010
Global average: ~ 55-60%
Dry season average: ~ 50%
Wet season
average: ~10%
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover Dynamics > Conclusion
Folie #
7 7
Slide
Temporal Compositing
Combination of Aqua and Terra
observations for the generation of:
- 16-day composites
- Monthly composites
- Dry season composites
By using a new cloud mask in the
compositing process, ca. 15% of clear
observations could be retained
compared to the standard MODIS
composite products.
Leinenkugel et al. (2013). Comparison and enhancement of
MODIS cloud mask products for Southeast Asia. International
Journal of Remote Sensing, 34, p2730-2748
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover Dynamics > Conclusion
Folie #
8 8
Slide
Extraction of phenological parameters
-C1=6
-C2=7.5
-L=1
-G=2.5
l_s1
l_s2
Parameter
Definition
s
time for the start
of the season
certain of the seasonal amplitude
measured from the left minimum
level
e
time for the end
of the season
decreased to a user
defined level measured from the
right minimum level.
l
length of the
season
time from the start to the end of
the season
b
base level
average of the left and right
minimum values
x
largest data
value during the
season
maximum value between start
and
end of season
m
smallest data
value during the
season
minimum value between start
and
end of season
a
seasonal
amplitude
difference between the
maximum value and the base
level
i
seasonal integral
Sum of values from the season
start to the season end
x_s1
x_s2
a_s1
s_s1b_s1
m_s1
i_s1
e_s1 s_s2 a_s2
m_s12
e_s2
m_s2
b_s2
i_s2
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover Dynamics > Conclusion
Folie#1010
Slide
Phenological characterisation of the Mekong Basin
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover Dynamics > Conclusion
Folie#
1111
Slide
The MEKONG LC2010 land cover map
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover Dynamics > Conclusion
Folie#1313
Slide
Land cover comparison for the Mekong Delta
MEKONG LC 2010
GlobCover 2009
MODIS Land Cover 2009
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover Dynamics > Conclusion
Folie#1414
Slide
Subpixel land cover estimation for 2001-2011
Reflectance
2001-2011
Land cover proportions 2001-2011
Forest
Woodland
High resolution
Satellite data
Classification
Aggregation to
subpixel land
cover proportion
MODIS
Reflectance
Phenology
Regression
Model
Cropland
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover Dynamics > Conclusion
Tree Density
Folie#1515
Slide
Detection of land cover changes
Temporary forest cut (shifting cultivation)
Permanent forest cut (large plantation)
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover Dynamics > Conclusion
Folie#1717
Slide
Conclusion and Outlook
Clear-sky surface reflectance composites were generated by
combining satellite data from two platforms and the application of
enhanced cloud masks
Phenology of the land surface was characterised for the entire
Mekong Basin based on EVI time series for 2001-2011.
A comprehensive land cover map was derived based on spectral
and temporal information for the year 2010.
Subpixel land cover proportions and continuous fields of tree
density was estimated for the time period 2001-2011
Still to do:
Detecting different types (temporary/permanent, gradual/abrupt)
of land cover change
Spatio-temporal analyses of land cover changes (relating change
to population density, distance to infrastructure/settlements etc.)
Introduction > Compositing > Phenology > Land Cover 2010 > Land Cover dynamics > Conclusion
Folie#1818
Slide
Thank you for your attention!
Email: [email protected]
Folie 19