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Asaye Nigussie
Advisors:Prof.Zerihun WolduDr.K.S.R Murthy
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1.Introduction
� deforestation, grazing cattle, human habitation and over fishing in the park have caused severe stresses and degradation of park ecosystems, leaving the sustainability of NSNP resources in question. (Alison M. Jones, 2005)
� The park had been excessively encroached by invasive plant species and the small but rare groundwater forest had been subjected to unsustainable illegal harvesting(Report of African Parks foundation, 2005)
1.1.Statement of the problem
Freeman(2006) Natural Resource Challenges of NSNP
NSNP
Forest
Springs
Wild Animals(land-based)
Grass land
Wild animals(lake-based)
Fish
Swamp,Sokke
Grazing land
Cut for firewood
Habitat being destroyedover-grazing
Nowhere for towns people to graze cattle
Being over-cut
Depleted by over-fishing
Fish breeding area destroyed
Risk to numbers caused by lack of fish
Potential use by investors
Unknown impact on forest
Unknown impact on lake and resources
Farming land
Land degraded
1.2.Objectives of the study
1.2.1 General objective :to analyze the trend of land and vegetation cover dynamics for the period starting from 1976-2007 thus to assess and examine the conservation status of the area and generate up-to-date land cover map
� To assess the trends of land and vegetation cover dynamics in the study area during the period from 1976, 1986 and 2000,
� To generate up to date land cover map for the year 2007,
� Studying the conservation status of NSNP focusing on invasive plants encroachment and land degradation,
� To show the annual biomass growth response,
1.2.2.Specific objective
2.Description of the study area2.1. Location �Located in Africa�s
Great Rift Valley, 575km southwest of Addis Ababa,
� Diverse Habitat
-Open grass land
-Ground water & riparian vegetation
-Lake shores
-Dense Bush land
-Acacia woodland
2.2 Climate
According to Ethiopian climate classification
-NSNP is classified in Hot Semi arid tropicalclimate
Arbaminch Meteorological Station 60 04�N 37036�E, 1300 m a.s.l
Dry season
Wet season
2.3 Biodiversity : Flora and FaunaVegetation diversityGW & riparian vegetation
Ficus sycamorus ,
Cordia africana,
Teclea nobilis
Open grass land
Savanna grass types
Acacia wood land
Acacia mellifera,
Acacia tortilis,
Rhus natalensis
Steep & hill vegtn(1300-1650m)
Combretum molle,
Euclia divinorum
Dodonea angustifolia
High elevation vegetn(>1650m)
Myrisine Africana,
Erythrina brucei,
Arundinaria alpinaLake shore vegetnTypha domingensisSaccharum spotaneumSesbania sesban
Rich fauna diversity and next to Mago national park in mammalian diversity
2.4 Topography and HydrologyNechisar plains are bounded by:North lake Abaya ,South and southwest lake Chamo
Abaya receives 86.484mm3
of discharge annually, while lake Chamo receives only 29.250mm3
Kulfo �flows from North of Arebamench & runoff joins lake shores of Chamo-Irrigation at chamoleto
Arebamench(Traditionaly 40 springs)-GWF
Seremele- perennial & runs along the eastern most cultivated fertile flood plains,
2.5 SocioeconomicRural:Weredas adjacent to the national park livelihood are farming, fishing, Tourism & petty trade
Communities inside the park
Kore-Live in Amaro Mountains & cultivate the Sermele floodplain
Guji- are nomadic pastoralists grazing approximately 4000 � 5000heads of stock in the park
Urban :Arebaminch 168,172ha estimated area,Population 232,000with 50.8% male and 49.2% female proportion (SNV,2006).
Livelihood: Farming crops:maize, sorghum, Fruits:bananas , mangos ,apples and pears,FishingFishing
--Tourism Tourism service (hotels and tour operators), Trade ,Employment
3.Materials and Methods
� Software & program :ArcGIS 9.2, ERDAS Imagine 9.1, Map source,
� GPS-receiver (Garmin), � Digital Camera,� Topo map of the study area (1:50,000 scale)� Multi dated Satellite images (Landsat images
1976-MSS,1986-TM and 2000-ETM+, 2006-ASTER)
� MODIS NDVI-image(2000&2005)� SRTM (90m contour interval)
3.1.Materials
LandsatMSS (1976)
LandsatETM+(2000)
Landsat TM (1986)
Image processing (Remote sensing techniques)Image rectification
Image enhancementImage classification
UnsupervisedSupervised
Image interpretation Accuracy assessment
ASTER image 2006
-Topo map(1:50,000)-Secondary data and previous land use/cover maps, -Google Earth image, KML files-SRTM
-Field ground verification-Senior park staff and Scout interview -Community discussion-Workshop proceedings
Out putsLand cover change comparison thematic maps
Up-to-date land cover map of NSNPStatistical results of cover change dynamics(charts, graphs, index values)Impacts of the cover dynamics and the conservation status of the national park
GIS data integration and statistical analysis-Cover change comparison-Land Cover change rate & Conversion matrix-NDVI Seasonal vegetation cover response -Landscape fragmentation index
MODIS-NDVI Images for 2000 and 2005
3.2.Methodology
1. Identifying Land use/cover data sources Bolton(1970) distribution of main land cover types Topo map,1979-1985 FAO/UNDP(1992), RVLB LU/LC map, Assistance to
land use planning project2.Sattelite image visual interpretation (TCC/FCC Band
combination, select training site pixels, Google earth image KML files, field inventory)
3.Unsupervised & Supervised cover classification and accuracy assessment
4. Land cover classification and result interpretation, statistical analysis (cover change rate, conversion matrix, fragmentation index)
3.2.1.Data analysis and Organization
4.Results and Discussion
-Unsupervised classes of Landsat 2000 gives the classes which are verified at field
-10 major land cover classes are identified and training classes are set for each year satellite image
-Accuracy assessment for each year cover map conducted
4.1.Unsupervised classification and select basic land cover units
Land and vegetation cover classes identified in NSNP for this study
REPARIAN & GW FOREST1 ACACIA WOOD LAND2
BUSHY SHRUBBED GRASSLAND3 OPEN GRASS LAND4
BARE BUSHED GRASSLAND5 CULTIVATED LAND6
SWAMP VEGETATION7 DENSE BUSH LAND8
BARE LAND & EROSION10
WATER BODY9
4.2.Land Cover classification thematic maps
1%
4%
2% 25%
11%
11%
11%6%
30%
Riparian and GW forest
Wood land
Dense bush land
Bushy shrubbed grass land
Open grass land
Open bushed grass land
Cultivated land
Swamp vegetation
Water body
2%
26%
1%
10%13%
31%
7%
6%
4%
Riparian and GW forestWood land Dense bush land
Bushy shrubbed grass landOpen grass land Open bushed grass land Cultivated land
Swamp vegetation Water body
1%
5%
12% 14%
12%
14%
6%6%
30%
Riparian and GW forest
Wood land
Dense bush land
Bushy shrubbed grass land
Open grass land
Open bushed grass land
Cultivated land
Swamp vegetation
Water body
2%
26%
1%
10%13%
31%
7%
6%
4%
Riparian and GW forest
Wood land
Dense bush land
Bushy shrubbed grass land
Open grass land
Open bushed grass land
Cultivated land
Swamp vegetation
Water body
Land cover classes for 2007
4798, 10%
1819, 4%
3231, 7%
10124, 21%
7610, 16%3549, 7%
2532, 5%
14531, 30%
Riparian and GW forest
Wood land
Dense bush land
Bushy shrubbed grass land
Open grass land
Degraded grass land
Cultivated land, Swamp and bare
Water body
Accuracy assessment
The final up to date cover map is generated using the information of past classification , field inventory and accurate training selection
GCP were used to validate the Landsat and ASTER imageclassification accuracy assessment and the error matrix gives average results:
78% accurate for 1976 Landsat-MSS image,
80% accurate for 1986 Landsat-TM image,
72.22% accurate for 2000 Landsat-ETM+ image and
95% accurate for 2007 Land cover map using ASTER image
Up- to date Land cover map & Classification Accuracy assessment
1.Cover change comparison for 1976,1986 ,2000
Land cover comparison
0
2000
4000
6000
8000
10000
12000
14000
16000
1 2 3
years(1-1976,2-1986,3-2000)
Are
a(h
a)
Riparian and GW forest
Wooded grass land
Dense bush land
Bushy shrubed grass land
Open grass land
Open bushed grass land
Cultivated land
Swamp vegetation
Water body
Uneven distribution of land cover class for the spatial and temporal dynamics in the past 24 years
From 1976 to 1986,
-a total loss of grassland 562.6ha/year
-Bushy shrubbed grass land has increased at a rate of 714.1ha/year,
From 1986-2000
-a drastic loss of the swamp vegetation at a rate of 92ha/year
-Riparian and GW forest have shrunk at a rate of 3.34ha/year
-cultivated land expand during the two periods at a rate of 1.12ha/year and 12ha/year
Cover change comparison for 1976,1986 ,2000 & 2007Land cover class comparison
02000400060008000
10000120001400016000
Rip
aria
n an
d G
W
fore
st
Woo
d la
nd
Den
se b
ush
land
Bus
hy s
hrub
bed
gras
s la
nd
Ope
n gr
ass
land
Bar
e bu
shed
gras
s la
nd
Cul
tivat
ed,S
wam
p
and
bare
land
Wat
er b
ody
Land cover class
Are
a(H
a)
1976
1986
2000
2007
-Progress in the Riparian & GW forest, Open grass land,Bushhy shrubbed grass land
- Cover decline in cultivated land ,Bare bush grass land, Wood land, Dense bush land
-Water body is constant and spatial changes are insignificant
2.Rate of Land cover change
+6.56
-46.95
+82.5
+197.25
-265.7
+122.05
+25.35
-147.95
-7.025
Net change rate
121.12Water body
-92-1.9Swamp vegetation
12144Cultivated land
54.78394.5Bare bushed grass land
31.2-562.6Open grass land
-470714.1Bushy shrubbed grass land
275-224.3Dense bush land
129-424.9Wood land
-60.8546.8Riparian and GW forest
1986-20001976 - 1986Land cover class
Rate of land cover change (ha/year)
0
2000
4000
6000
8000
10000
12000
14000
16000
0
2000
4000
6000
8000
10000
12000
14000
16000
Series2 1986 3559.2 1104.58 2873.42 12367.7 6328.4 4881.3 721.197 1892.22 14553.1
Series3 2000 2707.96 2910.78 6726.57 5787.85 6765.12 5648.31 2417.42 595.298 14723.7
Series1 1976 3091.1 5354.35 5116.53 5226.02 11954.4 936.037 280.389 1911.06 14541.9
Cover classificati
on
Riparian and GW
forest
Wooded grass land
Dense bush land
Bushy shrubed
grass land
Open grass land
Open bushed
grass land
Cultivated land
Swamp vegetation
Water body
Are
a(h
a)
3.Land cover change Conversion matrixConversion Matrix for 1976 and 1986
0
1000
2000
3000
4000
5000
6000
Riparia
n an
d GW
fore
st
Woo
d lan
d
Dense
bus
hlan
d
Bushy
shru
bed
gras
s lan
d
Open
gras
s lan
d
Bare
bush
ed g
rass
land
Cultiva
ted
land
Swamp
vege
tatio
n
Wat
er b
ody
Land cover types
Are
a(h
a)
Riparian and GW forest
Wood land
Dense bush land
Bushy shrubed GL
Open grass land
Bare bushed GL
Cultivated land
Swamp vegetation
Water body
Conversion matrix for 1986 and 2000
0
1000
2000
3000
4000
5000
6000
Riparia
n an
d GW
fore
st
wood
land
Dense
bus
h lan
d
Bushy
shru
bed
gras
s lan
d
Open
gras
s lan
d
Bare
bush
ed g
rass
land
Cultiva
ted
land
Swamp
vege
tatio
n
Wat
er b
ody
Land cover class
Are
a(h
a)
Riparian and GW forest
Wood land
Dense bush land
Bushy shrubed GL
Open grass land
Bare bushed GL
Cultivated land
Swamp vegetation
Water body
1976 to 1986Most covers are converted dominantly:to dense bush land, bare bushy grass land cultivated land and Bushy shrubbed grass land
1986 to 2000
Open grass land ,swamp vegetation and Riparian vegetation taken by mainly Bushy shrubbed grass land and Bare bushed grass land
4.Landscape fragmentation
368036373635Water body9
182423Swampy vegetation8
134846Cultivated and bare land7
226440Bare bushed grass land6
60253341Open grass land5
2111969Bushy shrubbed grass land4
333434Dense Bush land3
223555Wood land2
79147134Riparian and GW forest1
Pa value for 2000
Pa value for 1986Pa value for 1976
Land cover classesNo
The park habitat is highly treated and most cover classes have shown a fragmentation index value that describes the NSNP is highly disturbed
Fragmentation of ecosystems into small patches can reduce habitat for wildlife species that require larger, connected patches and introduce predators, parasites, and competitors (Core national indicator, 2000)
TRRM rain fall data (2000-2006)
GW & Riparian
Grass land
Bare land
Water body
Wood land
Swamp veget
Bush land
High Biomasgrowth
-April,May,October & November
Less biomasgrowth
-January to march,June to september and december
4.3.MODIS NDVI Image analysis-to see the temporal biomass growth
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
0
50
100
150
200
250
300
Ra
infa
ll in
Ne
ch S
ar
NP
(mm
)
2000200120022003200420052006Average
2005 NDVI profiles
2000 NDVI profiles
4.4.NSNP natural resource challenges and conservation status
Though natural processes contribute to change in land cover, the major driving force is human induced land uses (Allen and Barnes, 1985)
Major ecological challenge faced in the NSNP due to anthropogenic and natural factors
the surrounding population is currently growing rapidly, consequently inducing high pressure on the resource base of NSNP
Different studies show Cattle grazing in the Nechisar plain, poaching of wildlife, illegal fishing and felling of timber from the groundwater forest, farming at Kulfo and Seremele valley encapsulate the main problems
Socio-economic setting are influenced by the existing environmental conditions and Political unrest during the early 1990s led to intense damages in a relatively short period of time
Natural challenges includes Bush encroachment, invasive plant expansion
Riparian and GW forest situationProgress in forest cover
Total cover in the year 2007 4798ha which is highest compared to previous classes
Supportive measures
-The forest Guarding strategy implemented by APF-Ethiopia
-Restoration of cultivated areas at Chamo letto & Seremele riparian vegetation
-Future afforestation programs which will be implemented for Arebaminch town wood supply
- Alternative energy option project
-Community participation for park resource management
Control forest degradation
Sermele forsest restoration
Chamoletto forest degradation
Open Grass land situationChallenges
The GL is degraded heavily where livestock density is high,Landdegradation & erosion are seen at overgraze plain
-Malvaceae family Invasive plant(Abutilon bidentatum ) and Bush encroachment (mainly Dichrostachys cinerea, Acacia mellifera and Acacia oerfeta)
Supportive measures
-17 hectares of GL were cleared of invasive plant species (APF,2005)
-In 2007 Open GL covers 16% of the total area, higher than the 1986 and 2000 GL spatial cover
31
? ? ?
5.Conclusion and Recommendation In the past three decades as the population around Nechisar
National Park and nearby Arba Minch increases, so do the Pressure to the park natural resource such as grazing cattle at Nechisar plain, farming expansion,etc
The results of the thematic maps for land cover classes of 1976, 1986, 2000 and 2007 shows uneven dynamism for the different land cover classes except the changes for the water body is relatively insignificant or uniform
There is a tremendous land cover change in the open grass land cover as compared to other cover classes and it�s calculated a total loss of grassland, 562.6ha/year over the 10years of 1976-1986
Bushy shrubbed grass land has increased highly for the first 10 years period from 1976-1986 at a rate of 714.1ha/year, and second period from 1986-2000 by 470ha/year.
Habitat fragmentation is also a serious challenge in the park for the different land and vegetation cover classes as the broken patches of land cover results a fragmented landscape which is unhealthy for the ecosystem functioning.
Remote sensing and GIS to study Land cover dynamics could facilitate for a proactive planning process that enhances the implementation of sustainable natural resource management for decision makers, park managers and other stakeholders.
Recommendation� The Nechisar plain is severely affected by environmental and
anthropogenic challenges thus needs priorities to completely stop Farming, overgrazing and plan appropriate bush encroachment controlling strategy.
� The dependency of the surrounding community to the natural resources of the park has to be a priority agenda and for successful and win-win solution there should be the integration of different actors to start participatory park management and ecotourism projects
� The ground water forest which is unique habitat for the countryhas to be protected from any exploitation and investment projects such as water bottling industries which are already proposed by investors and this should be discouraged unless detailed impact assessment is conducted.
The situation in the park has shown improvement once APC Ethiopia is taking the responsibility to manage the national park, to realize the vision of APC & to set the Nechisar national park a model to other treated parks in the country all actors participation is important
Due to current situation there should be a quick response for a wise decision before the park resource is aggressively devastated while conflicts among the surrounding communitiesarise during transitional periods between APC�Ethiopia, Regional Governments and the Federal Government.
Finally I recommend for further researchers to study the impact of vegetation cover dynamics on the situation of endangered wild life such as Swayenes heartbeets and to conduct a scenario analysis on the relationships of natural resource degradation and wildlife extinction.
Thank you!
Lets be responsible for the only Nature!
Acknowledgement
� My supervisor Prof. Zerihun Woldu� HoARENC� AAU Earth science department � AAU Biology department,Herbarium center� African Parks Foundation (APC p.l.c �NSNP)� GO�s and NGO�s� Friends� Family