Predictive Vegetation Mapping of Bara and Rautahat Districts Using ANN
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Transcript of Predictive Vegetation Mapping of Bara and Rautahat Districts Using ANN
“Predictive Vegetation Mapping Of Bara And
Rautahat Districts Using Artificial Neural Network”
Project Members
Maheshwor Karki (14)David Nhemaphuki (18)Bibek Karki (13)
Email id: [email protected]
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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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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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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3. ObjectiveMain 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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4. Study Area
• Geographic coordinates:Bara: 2 2’ N 8 0’E 7͘͘͘5͘7͘͘͘((( 5͘(Rautahat: 2 46’ N 8 16’E6͘5͘6͘( 5͘(
• Area:Bara: 1190 sq. kmRautahat :1126 sq. km.
• Climatic Zones:Lower TropicalUpper Tropical
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Map of Nepal
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5. Methods
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Image Classification
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Figure : Image Classification Algorithm
Downloaded Landsat Images
Radiometric Calibration
Dark pixel subtractions
Image Pre-processing
NDVI Image Enhancement
Tasselled Cap Brightness
Selection of ROI Image Classification (Supervised: Maximum Likelihood Algorithm)
Forest and Non Forest Map
Accuracy Assessment
Composite Image
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Change Detection
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Classified Image 1999
Classified Image2009
Classified Image2013
Image Differencing1999-1989
Image Differencing1999-2009
Image Differencing2009-2013
Temporal Change Detection Map
Figure : Change Detection Method
Classified Image 1989
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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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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 network11
6. Result
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Accuracy Assessment
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2009 2013
Overall accuracy 95.83% 87.85%
Kappa coefficient 0.91 0.76
study2013_ Non_Forest Forest Ground truth
Non_Forest 60 5 65
Forest 10 63 73
Total 70 70 140
study2009 Non_Forest Forest Grount truth
Non_Forest 60 5 65
Forest 0 55 55
Total 60 60 120
Confusion Matrix: 2009 Confusion Matrix: 2013
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Land Cover
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Class1989 1999 2009 2013
Change(%) 1989-1999
Change(%) 1999-2009
Change(%) 2009-2013
Change(%) 1989-2013
Forest 48940 48003 45134 43140 -1.91 -5.98 -4.42 -11.85Non-Forest 78282 79215 82084 84078 1.19 3.62 2.43 7.40
Year
Class1989 1999 2009 2013 Change(%)
1989-199Change(%) 1999-2009
Change(%) 2009-2013
Change(%) 1989-2013
Forest 29336 27897 25308 25509 -4.91 -9.25 0.79 -13.05
Non-Forest 74285 75726 78315 78114 1.94 3.42 -0.26 5.15
Land cover of Bara district
1989 1999 2009 201323000
24000
25000
26000
27000
28000
29000
3000029336.85
27897.39
25308.36 25509.69
Forest Area Rautahat
Year
Fore
st A
rea
(hec
tare
s)
1989 1999 2009 20134000041000420004300044000450004600047000480004900050000
48940.6548003.84
45134.91
43140.69
Forest Area in Bara
year
Area
Of f
ores
t in
hect
ares
Land cover of Rautahat district
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Change Maps
Figure: Change map of Bara: 1989-1999 Figure: Change map of Bara: 1999-200915
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Figure. Change map of Bara: 1989-2013Figure. Change map of Bara: 2009-2013
Cont…
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Figure. Change map of Rautahat: 1989-1999 Figure. Change map of Rautahat: 1999-2009
Cont…
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Figure. Change map of Rautahat: 1989-2013Figure. Change map of Rautahat: 2009-2013
Cont…
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Deforestation RateFAO 1995 formula:q=((A2-A1)^1/(t2-t1))-1Where,
q=deforestation rate(% lost areal year)A1=initial forest areaA2=final forest areat2-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/A1Where,
r=deforestation rateA1=initial forest areaA2=final forest areat2-t1=interval in years during which change in land cover is being assessed 19
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Deforestation Rate1989-1999:r=.0019331999-2009:r=.0061632009-2013:r=.011297
1989-1999 1999-2009 2009-20130
0.002
0.004
0.006
0.008
0.01
0.012
0.001933
0.006163
0.011297
Deforestation Rate in Bara
Time Interval
Defo
rest
ation
Rat
e
1989-1999:r=.00503121999-2009:r=.00973972009-2-13:r=-.001980 1989-1999 1999-2009 2009-2013
-0.004-0.002
00.0020.0040.0060.008
0.010.012
0.0050312
0.0097397
-0.00198
Deforestation Rate in Rautahat
Time Interval
Defo
rest
ation
Rat
e
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Spatial Metrics
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Bara spatial metrics(1989/1999/2009/2013)
class Metrics
1989 1999 2009 2013
Forest Non-Forest Forest Non-Forest Forest Non-Forest Forest Non-Forest
CA-Class Area 48940 78282 48003 79215 45134 82084 43140 84078
NP-Number of patches
823 1779 350
2179 147 1043 233 3158
ED-Edge Density
17.45 18.71 15.83
17.22 11.43 12.74 20.57 21.98
LPI- Largest patch Index
22.15 55.30 21.66 56.21 10.63 61.43 10.46 62.51
CONTAG 43.4473 44.3296 47.0926 53.9301
Class
Metrics
1989 1999 2009 2013Forest Non-Forest Forest Non-Forest Forest Non-Forest Forest Non-
Forest
CA-Class Area
29336 74285 27897 75726 25308 7831 25509 78114
NP-Number of patches
364 1017 148 1040 117 1657 376 1609
ED-Edge Density
11.80 13.28 10.64 12.37 12.61 14.31 16.73 18.39
LPI- Largest patch Index
26.42 69.33 14.21 71.270 23.22 73.98 11.11 73.46
CONTAG 50.9184 52.3493 53.4769 51.6868
Rautahat Spatial metrics(1989/1999/2009/2013)
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1989 1999 2009 20130
5
10
15
20
25
22.1545 21.6623
10.6344 10.4668
Largest Pitch Index Bara
Year
LPI
1989 1999 2009 20130
5
10
15
20
25
17.453415.8349
11.436
20.5733
Edge Density Bara
Year
Edge
Den
sity
1989 1999 2009 20130
200
400
600
800
1000
1200
1400
1600
823
350
1478
233
Number of forest patches in Bara
Year
NO
of f
ores
t pat
ch
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1989 1999 2009 20130
2
4
6
8
10
12
14
16
18
11.806910.6469
12.6127
16.7341
Edge Density Rautahat
Year
Edge
Den
sity
1989 1999 2009 20130
5
10
15
20
25
30
26.4208
14.2181
23.223
11.1175
Largest Patch Index Rautahat
Year
Larg
est P
atch
Inde
x(LP
I)
1989 1999 2009 20130
50
100
150
200
250
300
350
400364
148117
376
Number of Forest patches Rautahat
Year
No
of F
ores
t pat
ches
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Prediction
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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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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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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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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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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 Wed
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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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Thank you!
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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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