Using Artificial Neural Network Model for the prediction of forest cover of Rautahat an Bara district. Analyze the changing pattern of the forest in these area.
2. 1.Background
• Forest degradation a challenge for biodiversity conservation
• Agricultural encroachment, Forest extraction, sand and gravel extraction, Urbanisation
• Forest area 4 billion hectares in the world, 13 million hectares of forest is converting in
other use each year(FRA,2010)
• In Nepal,
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• 20 Terai districts 0.06% during 1990/91 to 2000/2001(Nepal’s forestry outlook
study,2009)
1.7% per year
1978/79 1994
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3. 2.Introduction
Classification, Change Detection
Prediction and Mapping
• Provides underlying picture of
changes in Land use and land
change
• Predict geographic distribution of
the vegetation composition
• Managing natural resources
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4. Contd…
Artificial Neural Network (ANN)
• Is a feed-forward model
• Back propagation learning algorithm
• Improves itself by making corrections to its internal structure
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5. 3. Objective
Main objective
• To predict vegetation using models Artificial Neural Network
Sub objectives
• To prepare the Multi Temporal Vegetation Coverage Map
• To detect the changes
• To find out the spatial pattern of vegetation
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6. 4. Study Area
• Geographic coordinates:
Bara: 27͘͘͘͘͘͘͘͘͘ 2’ N 85͘͘͘ 0’E
Rautahat: 26͘͘͘ 46’ N 85͘͘͘ 16’E
• Area:
Bara: 1190 sq. km
Rautahat :1126 sq. km.
• Climatic Zones:
Lower Tropical
Upper Tropical
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10. Artificial Neural Network
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• Emulates properties of biological
nervous system and draw on the
analogies of adaptive biological
learning
Why ANNs?
• More accurate than traditional statistical methods
• ANNs can learn from and generalize from experience
• ANNs are universal functional approximator
• Ability to combine data from different source
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11. Artificial Neural Network
Model Development
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Classified Vegetation map
DEM
Slope
Aspect
Distance from road
Distance from Settlement
Input Layer Hidden Layer Output Layer
nodes
Figure : multi-layer perceptron neural network
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19. Deforestation Rate
FAO 1995 formula:
q=((A2-A1)^1/(t2-t1))-1
Where,
q=deforestation rate(% lost areal year)
A1=initial forest area
A2=final forest area
t2-t1=interval in years during which change in land cover is being assessed
Puyravad Formula:(Based on compound interest and more intuitive than FAO formula)
r=1/(t1-t2)lnA2/A1
Where,
r=deforestation rate
A1=initial forest area
A2=final forest area
t2-t1=interval in years during which change in land cover is being
assessed
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26. Figure: Predicted Land cover map of 2013Figure: Classified Land cover map of 2013 Figure: Change map
Prediction of 2013 land cover
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Classified 2013 Predicted 2013
Bara(forest) Rautahat(forest) Bara(forest) Rautahat(forest)
Area(hectare) 43140 25509 41437 23143
NP 233 376 898 699
ED 20.57 16.73 18.68 14.43
LPI 10.46 11.11 11.12 10.72
CONTAG 53.93 51.68 65.37 70.94
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27. Thursday,July31,2014
Figure: Predicted land cover map of the Study area
Prediction of 2020 land cover
Forest area change
(2013-2020):
=68648 -64587
=4061
Deforestation rate
during 2013-2020:
0.0057
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28. Discussion
• From the year 1989-2013, 5800 and 3800 hectare of forest area has been decreased
in Bara and Rautahat
• ICIMOD - Nepal Land Cover Map 1990 and 2010 deforestation rate is -0.0002 while
the deforestation rate of Bara is 0.0009. Our study shows that there is high
deforestation in both districts with deforestation rate of 0.0040and 0.0074
• Forest area has been increased in Rautahat during 2009-2013 due to people’s
participation and community forest programme through collaborative forest
management
• The predicted rate of deforestation is 0.0057 during 2013-2020 of study area
• There is high annual rate of deforestation rate during 1999-2009 in both districts in
our case.
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29. Limitations
In field:
• All places are not accessible due to limited time
• Data collection time is limited in the morning and evening due to high
temperature
Data
• Availability of data is a major problem of this study
• There is no data for the accuracy assessment of the classified image of the year
1989 and 1999
• Social, economic, political and cultural factors have not considered here
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30. Recommendation
• Other variables like solar radiation, climatic data, soil data can be used
• Exchange between forest sub classes could be computed and predicted
• Accuracy assessment of 1989 and 1999 could be done
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31. Conclusion
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• Change detection and prediction of vegetation mapping of Bara and Rautahat was
done
• Rate of deforestation for 2013-2020 has been predicted 0.0057 and also showing
significant change of forest in the past
• Timber extraction, urbanisation, agricultural encroachment, sand and gravel
extraction, soil erosion are found to be major cause of deforestation
• High rate of deforestation near the forest boundary and settlement area than near
the highway
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34. Thursday,July31,2014
Explanatory Variable Cramer’s V Test
Distance from roads 0.1703
Distance from settlement 0.4782
DEM 0.7927
Slope 0.2665
Aspect 0.1609
Level of association Verbal description Comments
0.000 No Relationship Independent variable does not help in predicting the
dependent variable
0.00 to 0.15 Very weak Not generally acceptable
0.15 to 0.20 Weak Minimally acceptable
0.20 to 0.25 Moderate Acceptable
0.25 to 0.30 Moderately strong Desirable
0.30 to 0.35 Strong Very desirable
0.35 to 0.40 Very strong Extremely desirable
0.40 to 0.50 Worrisomely strong Either an extremely good relationship or the two variables
are measuring the same concept
0.50 to 0.99 Redundant The two variables are probably measuring the same concept
1.00 Perfect relationship If we know the independent variable, we can perfectly
predict the dependent variable
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