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