DISTURBED ECOSYSTEMS DYNAMICS IN THE ARAL SEA
REGION INVESTIGATED BY REMOTE SENSING
AND GIS METHODS
SPOT-4 VEGETATION PREPARATORY PROGRAMME
Intermediate report
NDVI dynamics in the Amu Darya delta during vegetation period of 1995
PI:
R. Ressl, German Aerospace Center (DLR), Oberpfaffenhofen, Germany
Co-I:
Co-I:
Co-I:
Co-I:
Co-I:
A. Ptichnikov, Institute of Geography RAS, Moscow, Russia
G. Kapustin, Institute of Geography RAS, Moscow, Russia
D. Forstman, Institute of Geography RAS, Moscow, Russia
N. Novikova, Institute of Water Problems RAS, Moscow, Russia
P. Reimov, Karakalpak Sate University, Nukus, Karakalpakstan,Uzbekistan
1. TABLE OF CONTENTS
1. TABLE OF CONTENTS.....................................................................................................................2
2. SUMMARY ......................................................................................................................................... 3
3. OBJECTIVES OF THE INVESTIGATIONS ................................................................................. 3
4. DERIVATION OF LANDCOVER/LANDUSE CLASSIFICATIONS OF THE STUDY AREA
UTILISING SATELLITE IMAGES ................................................................................................. 3
4.1. KEY AREAS SELECTION AND FIELD OBSERVATIONS ........................................................................ 3
4.2. CLASSIFICATION OF DIFFERENT NATURAL AND MAN-MADE ECOSYSTEMS USING MULTI-SOURCE
SATELLITE IMAGERY ..................................................................................................................... 4
4.3. USING SATELLITE PHOTOIMAGES FOR MANUAL ECOSYSTEM DETECTION ........................................ 6
4.4. OBJECTIVES OF FUTURE INVESTIGATIONS ....................................................................................... 6
5. STUDY OF LANDCOVER / LANDUSE CHANGES OF THE NON-IRRIGATED PART OF
THE DELTA ........................................................................................................................................ 6
5.1. SPATIAL CHANGING OF FORMER WETLANDS AREA.......................................................................... 6
5.2. ECOSYSTEMS CHANGES OF THE NON-IRRIGATED PART OF THE AMU DARYA DELTA ....................... 7
5.3. LANDCOVER AND ECOSYSTEMS CHANGES OF THE DRY BOTTOM OF THE ARAL SEA. ....................... 9
5.4. OBJECTIVES OF FUTURE INVESTIGATIONS ..................................................................................... 10
6. APPROACHES FOR INCORPORATION OF LANDCOVER/LANDUSE CHANGE MODEL
RESULTS IN THE ARAL GIS. ....................................................................................................... 10
6.1. GIS AND DATA-BASE REPLENISHMENT FOR FUTURE ECOSYSTEM MODELING ............................... 10
6.3. OBJECTIVES OF FUTURE INVESTIGATIONS DURING THE POST-LAUNCH PHASE ............................... 12
7. BIBLIOGRAPHY............................................................................................................................. 12
Cover page
This series of NOAA-AVHRR images shows the vegetation dynamics in the Amu-Darya Delta south
of the Aral Sea. The NDVI information is used in combination with high resolution satellite image
classifications for monitoring landcover / landuse dynamics and to model future ecosystem
developments.
2. SUMMARY
Starting with the intensification of irrigation activities in the beginning of 1960s in the AmuDarya delta and the entire Aral Sea region, the decreasing water inflow to the Aral Sea caused the rapid
desiccation of the Aral Sea and the progressive desertification and drying of the entire delta. The
ecological situation in the Aral Sea region changed dramatically during last decades. Regional
landscapes and hydrological systems (natural, semi-natural and man-made) are in a state of dynamic
disequilibrium as they adjust to the rapid and intense internal and external forces.
The aim of this project is to monitor the current state and the dynamics of ecosystems in the Aral Sea
region to determine the intensity and rate of degradation. In addition potential seasonal and perennial
ecosystem developments will be investigated using synergetic remote sensing data and GIS methods.
The investigations during the prelaunch period included the following tasks: project
management and methodology and case studies. The main investigation procedures existed primarily
out of large area observations, which enables the monitoring of the entire Amu-Darya delta to derive
small scale maps of the delta. The vegetation and ecosystem dynamics can be investigated and mapped
over the entire vegetation period on a high temporal frequency. In addition detailed investigations on
representative selected sites (incl. ground investigations) will be used to describe and model the
complex ecosystem dynamics. The results will be extrapolated to areas with similar conditions to
document the current ecological situation in the entire Amu-Darya Delta and to model future
developments.
3. OBJECTIVES OF THE INVESTIGATIONS
The three main objectives of the studies including VEGETATION data are the following:
1.
2.
3.
Creation of detailed landcover/landuse classifications of different parts of the investigated area,
utilizing various types of space images. Appropriate satellite images and classification routines
will be selected depending of the individual site features and targets of the studies.
Research of landcover/landuse changes and related ecosystems dynamics. Special interest is placed
on the spatial distribution and the rate and intensity of change. The basis of these studies are results
from satellite image classifications and field observations. The investigation results will be used to
produce thematic maps of the Amu-Darya Delta showing the degree of ecosystem desertification
and degradation and its spatial and temporal distribution.
Implementation of the results of the ecosystem dynamics investigations into the developed Aral
GIS and modeling of natural and man-made degradation processes in both irrigated and nonirrigated parts of the Amu-Darya delta.
4. DERIVATION OF LANDCOVER/LANDUSE CLASSIFICATIONS OF THE STUDY AREA
UTILISING SATELLITE IMAGES
4.1. Key area selection and field observations
Five key areas with training sites which show typical landuse structures in different parts of the
Amu-Darya delta were selected for detailed observations. These representative key areas are: BadaiTugai natural reserve; the vicinity of the city of Muinak; the vicinity of the city of Nukus; the Chimbai
region and the Shumanai region (Table 1) .
#
Key area
Center location
Landuse
State
1
Chimbai rayon
59º 45’ E / 43º 00’ N
Agriculture
Salinised
2
Shumanai rayon
58º 55’ E / 42º 37’ N
Agriculture
Salinised
3
Vicinity of Muinak city
59º 00’ E / 43º 46’ N
Semi-natural
Highly desertified
4
Vicinity of Nukus city
59º 37’ E / 42º 28’ N
Semi-natural
Semi-desertified, salinised
5
Badai-Tugai natural reserve
59º 47’ E / 42º 18’ N
Natural
Desiccated
Tab. 1: Short description of key areas in the Amu-Darya delta
Field observations have taken place since 1994 and the most recent expeditions were conducted to the
key areas in August/September of 1996 and in September of 1997. For each key area, especially for the
test sites in the rayon of Chimbai and Shumanai, complex ground observations were carried out for a
detailed description of the training sites. The investigations included the collection of vegetation and
soil samples for detailed plant studies and chemical soil analysis as a basis for validation of satellite
imagery analysis (Fig 1).
By ground investigation of the years of 1996-1997 more than 6000 field botanic descriptions
and 500 key site descriptions were incorporated in a Vegetation Information Database. The coordinate
of each location was determined with a Global Positioning System (GPS) and digital topographic maps.
The data was georeferenced to be able to use it in the existing GIS for the Amu-Darya delta and will be
used as a reference network of ground control points for the environmental modeling and ecosystem
assessment during the post-launch phase of the VEGETATION project.
Site collected data:
1.
2.
3.
4.
5.
6.
7.
8.
Date, coordinate
Plant communities
Plant species
Productivity
Phytomass
Soil samples
Soil chemistry
Ground water depth / salinisation
Fig 1: Field-measurements and ground samples for selected key areas
4.2. Classification of different natural and man-made ecosystems using multi-source satellite
imagery
For the evaluation of the ecosystem dynamics including VEGETATION data first a landuse
classification had to be derived to separate natural ecosystems from man made land structures and
landuse.
NOAA-AVHRR imagery with a fairly low geometric resolution of 1.1 km and five bands in the
visible and near infrared spectral range have been acquired for the time period between 1980 and 1994
and much more regularly for recent years (up to 5 scenes/ month). NOAA-AVHRR-data has been used
to describe the phenology development of the most important crop types in the Amu-Darya delta with
associated water demand. In addition water bodies were classified into several types (shallow water,
deep water, wetlands).
An actual landuse classification for the Amu-Darya delta was produced using Landsat MSS
scenes of the years 1993-1994 and by russian Resource-O1 MSU-SK scenes (175 m geometric
resolution) from 1995 and 1996 and partially from landuse maps of previous years. This information
was necessary for past long-term investigations of environmental changes and as a base information to
model future natural ecosystem developments.
For the rayons of Chimbai and Shumanai (research areas #1, #2) and around Nukus city (#4)
there is predominance of man-made agricultural landuse structures. Basically cotton and rice are grown
with sufficient large field sizes (>500m x 500m), which were classified through medium resolution
satellite imagery (Resurs-01 MSU-SK). More than 200 ground control points were collected as
reference and training site points as a basis for the supervised classification.
The critical ecological zones within the Amu-Darya delta were basically investigated by satellite
imagery analysis of high resolution remote sensing data. Landsat TM data of 1989 and 1994 has been
investigated to evaluate the effects of desertification of the deltaic ecosystems and their changes. Fig.2
shows the ”desertification stages” of the Amu-Darya delta, expressed in different categories concerning
the strength of environmental changes. The map gives an indication of how the ecosystems transform
from wetlands to semideserts over time and can be used in the GIS for future assessment of the
desertification and state of the few remaining biotops.
One of the main goals is the detection of the rate of desertification of the former wetlands as a
result of the desiccation of the Aral Sea. As this desertification rate is connected with the development
of the vegetation, changes in the vegetation complexes were studied as an indicator of the
desertification of the corresponding ecosystems. Besides of the available Landsat TM channels, the
Normalized Vegetation Index (NDVI) was merged as an additional input information layer to enhance
the classification results.
Initial desertification
Feasible desertification
Strong desertification
Very strong desertification
Irrigated fields
Water objects
Fig. 2: Desertification level of the ecosystems of the Amu-Darya delta (August 1989)
The results of the “desertification level” classification was implemented in the GIS for further
evaluation and to provide a basis for detailed environmental rehabilitation projects (scale 1:25000 1:100000). The degree of desertification and the different desertification levels in the Amu-Darya delta
can be seen in Fig. 2.
4.3. Using satellite photoimages for manual ecosystem detection
The dry bottom of the Aral sea, adjacent to the north of the Amu-Darya delta (key area #3), was
studied using high resolution space photoimages, obtained from the satellites of the Cosmos series due
to the absence of high resolution satellite imagery for the entire area of the dry bottom. The single
photos were mosaiced into a georeferenced ortho-photoplan. The detection of ecosystems was done
manually using color and texture characteristics as well as visual neighborhood relations. Ground truth
information was used as reference areas for the classification and the classes for the definition of the
desertification level were based on the dynamical changes in the process of desertification. The key
study area for the desertification investigations of alluvial deltaic ecosystems was the natural reserve
Badai-Tugai (#5). The Tugai forests used to be the ecological most valuable areas in the Amu-Darya
Delta with a rich variety of flora and fauna. Due the desiccation of the Aral sea and the absent
floodings, the desertification shows the most severe consequences within these ecosystems. The
investigations in this key area will be used as the indicator of changes in the entire Tugai (forest)
ecosystems.
4.4. Objectives of future investigations
Main objective is the desertification assessment of the entire Amu-Darya delta including the dry
bottom of the Aral sea using VEGETATION data. The existing satellite information and investigation
cover only selected portions of the delta and adjacent regions, but to present there is no desertification
assessment of the entire region.
Existing landcover/landuse structure maps, created by previous investigations will be the reference
information for this task. The results of an unsupervised classification of VEGETATION data in
comparison with multitemporal information of different years and including the basic understanding of
desertification development in the area enables to determine the current ecosystem status and
development. Furthermore by assessment of these time-intervals of desertification future desertification
developments can be defined. This is especially important in the most critical ecological parts of the
Amu-Darya delta to provide the necessary information to decision makers.
The information gathered during the investigations in the pre-launch phase will be used to derive
information for a sub-pixel classification of VEGETATION data and to enhance the results initially
limited by the lower geometric resolution of the sensor. In addition seasonal vegetation information
derived by multitemporal yearly VEGETATION data is expected to provide useful information on
short term ecosystem development within the overall desertification development and to help to model
current and future landscape dynamics.
5. STUDY OF LANDCOVER/LANDUSE CHANGES OF THE NON-IRRIGATED PART OF
THE AMU-DARYA DELTA
5.1. Spatial variations of former wetland areas
For a comparatively short period, from 1960s to the 1980s, the profound environmental changes
took place in the delta plains of the Amu-Darya.
Area in % of former wetlands
Landcover (ecosystems)/landuse
Wetlands not or slightly affected by desertification (hydrophyte or
20.14
hydrohalophyte ecosystems)
Salinizing or desiccating parts of wetlands(hydrohalophyte and
13.95
mezohalophyte ecosystems)
Salinized and desiccated parts of wetlands (sparce xerohalophyt or
25.42
xeromezophyte ecosystems)
Completely salinized or desiccated parts of wetlands (xerophyte ecosystems 28.67
or without vegetation cover)
Areas of irrigation
9.57
Lakes and rivers
2.25
Tab. 2: Status of desertification levels (stages) of ecosystems of the Amu-Darya delta in 1989
(derived from Landsat TM classification)
The area of open water surfaces, basically small lakes has decreased from 45 % to 3%. The
ground water table has dropped from 1-2 meters to 3-5 meters and in non-irrigated areas down to 10
meters. The mineralization of the ground water varies widely from 2 g/l to 57 g/l.
Reeds which used to occupy an area of 220,000 hectare and tree-shrub riverine forests have been
replaced by halophyte and xerophyte shrub communities. The overall biological diversity and
productivity was reduced significantly. Fertile meadow and bog meadow alluvial soils, which had
previously occupied about 40% of territory, have also dramatically degenerated. The results of the
ecosystem investigations can be seen in Tab. 2.
5.2. Ecosystems changes of the non-irrigated part of the Amu-Darya delta
Long-time field observations on the study of dynamics of ecosystems with satellite remote sensing and
aerial data show, that the chain of transformation from hydromorphic deltaic ecosystems into desert
ecosystems can be divided into fairly stable stadiums and periods of fast "jumping" changes. Each
more or less stable stadium is referred to as a "stage" whereas the entire chain is referred to as the "
Landscape-dynamic range" (LDR). Each stage can be characterized by 22-25 ecological parameters,
such as a certain type of phytocenosis, soil, ground water level and mineralization etc. (see Tab. 3),
which were compiled in the database.
Relief forms
Lithology of surface deposits
Genesis of surface deposits
Desertification processes
Character relief forms
Ground water level (m)
Ground water mineralization (g/l)
Soil type
Salt amount in 1 m soil profile
Chemical composition of soil salts
Soil pH
Humus amount in 1 m soil in %
Ecosystem type
Dominant species
Projective cover %
Productivity (kg/ha*year)
Stage duration (years)
Stability
Next LDR stage
Landuse type
Recommended phytomelioration
Smoothed depressions
Heavy clay loam, clays
Alluvial
Drying, salinisation
Lake microterraces, hillocks
3.5-5
30 - 50
Solonchaks crust-puffy takyric
3-8
S04
no data available
1–3
Xerogalophyte small shrubs
Tamarix Hispida, Phragmites australis,
Aeloropus litoralis, Halostachys Caspica
5-20
100 – 300
minimum 5 years
relatively stable
Bald takyrs
None (not used)
By black saksaul, karabarak
Tab. 3:: A fragment of database on the Amu-Darya delta: ecosystems of drying up lake depressions,
third stage of desertification (compiled by Dr. A. Ptichnikov).
In general the Amu-Darya delta can be divided into four main types of ecosystems, which are the
floodplains of the main river channel, deltaic fluvial levees and heights, interchannel depressions,
lowlands and lake lowlands. Each of these ecosystems is transforming under the influence of
desiccation and salinization. During the process of transformation it is possible to divide 4 fairly stable
stages followed by periods of fast transitions. The first stage of any type of ecosystem can be called
“initial stage”, the following “desiccation and salinization stage”, the next “desertification stage” and
finally the “posthydromorphic (semidesertic) stage”. Every stage is characterized by some ecological
indicators i.e. phytocenosis, soil, ground water level and mineralization, etc. The level of desertification
may be assessed through the vegetation changes, as the biologic productivity and biomass of vegetation
gradually decreases during the desertification.
During the desiccation process the chain of transformation of the deltaic ecosystems differs
depending of the ecosystem type and is highly determined by watering conditions, including surface
and ground water feeding (Fig. 3).
Xerophytization
Psammophytization
4
Former ground
water level
3
2
1
Desiccation
Floodplain
Ecosystem
Level of desertification
Xerohalophytization
New ground
water level
Hydrophytization
Fluctuation
1
Regular or
occasional
watering
Halophytization
2
Fig. 3: Simplified structural scheme of the Amu-Darya delta ecosystem dynamics
To determine the inter-relationship between the desertification and the main ecological factors
the correlation between the ground water table (gwt), ground water mineralization (min) and percent of
light fraction in the granulometric composition (gc) of soils in 1 m depth was calculated (Tab. 4). The
correlation in the general selection shows slight positive values (k = 0.30) between gwt and min. Field
investigation proved that the desertification is responsible for a subsidence of the groundwater table
and that deeper groundwater (gwt) resulted in a higher mineralization. Between gwt and gc there is a
slight negative correlation (k=-0.23) which shows that the higher the percentage of light particles in the
soil composition (gc) becomes the closer the groundwater (gw) gets to the surface. Between min and gc
there is also a moderate negative correlation (k=-0.37). The higher the percentage of small particles
(more sandy) in the soil, the less mineralized the ground water becomes. The desertification of the
levees composed by sandy deposits have not reached the solonchak stage because the evaporation from
the sandy soils is smaller.
factors
Gwt*
min**
Gc***
gwt
1
0.30
-0.23
min
0.30
1
-0.37
gc
-0.23
-0.37
1
gwt - ground water table; min - ground water mineralization;
gc - percent of the light fraction in granulometric composition
Tab. 4: Cross-Correlation between the main ecological factors
Some typical features of the ecosystem’s dynamics are the following (by N.Novikova):
1.
Stability: During the desertification process the fourth stadium is the most stabile whereas the
first, second and third stadiums are less stabile and shorter. The typical time duration of each
stadium depends of many factors. The average duration of stadium 4 under normal conditions is up
to a hundred years, of stadium 1, 2 and 3 dozens of years with transition periods in-between up to
5-10 years.
2.
Biologic diversity: The assessment of the biological diversity showed that plant communities of
Tugai forests during the level of formation are composed out of 24 units. They are adopted to
different ecological conditions: from non salty wetland habitats to solonchaks and dry takyrs. All
Tugai communities are developing to 3 subclimax stages (solonchaks, takyr, sands) through 3
main processes, which are the processes of desiccation, salinization and psammophytization.
Concerning the sustainability and ecological function, the biologic diversity is higher during the
first and fourth stage of the desiccation, while the second and third stadiums are transitional and
most unstable.
3.
Character of changes: In some cases the ecosystem’s changes might be irrevocable, as some key
species might lose their genetic sustainability and can’t be reproduced in new natural conditions.
Depending on the amount of water supply the ecosystems may fluctuate between some stadiums
and under conditions of quick ecological changes the ecosystems dynamics might also result in
“jumps“ excluding some stadiums. As an example it could be observed that some reed ecosystems
were transformed directly to the takyr stage.
5.3. Landcover and ecosystems changes on the dry bottom of the Aral Sea.
Initial vegetation started to settle on the dry bottom surface immediately after recession of the
Aral sea. The first plants appeared more than 35 years ago on the narrow beaches. With the declining
sea level the vegetation settles on the newly formed land. The principal transformation scheme of the
dry bottom vegetation is illustrated in Fig. 4 and can be described as following:
The vegetation along the former seabed of the Aral Sea forms several belts on the dry bottom.
These belts are attached to certain stages of the recession of the Aral Sea, which are usually referred to
as the sea bottom’s of 1960s, 70s, 80s and 90s. Currently the bottom of the 1960s is covered by
perennial communities and the ecological conditions are more favorable than on later belts. The bottom
of the 1980s up to today represents the wasteland (solonchaks, bare sands) without vegetation and is
the main source of salt- and dust storms.
The process of vegetation settlement is basically determined by the existing ground conditions,
especially by the soil salinity as a remnant of the desiccation of the sea. As salts on sandy soils are
removed faster than on clay soils the natural succession of vegetation results quicker on sandy soils.
Clay grounds show more constant conditions and are usually highly salinized and the process of
vegetation settlement takes 2-3 times longer.
During the process of transformation any ecosystem of the dry bottom is passing through 4 main
stages. The first stage is defined by the emerging beach, the second is called ephemeral stage (with fast
growth of ephemeral vegetation), the third wasteland stage (with dramatic degradation of ephemeral
ecosystems), and finally the neo-ecosystem stage with continuos transformation to desert conditions.
Like in the in Amu-Darya delta the landscapes of the dry bottom might be divided into different types:




Landscapes of gulfs with a semi-concentrical structure of ecosystems;
Landscapes of eluvial plateau shores with abundance of sands;
Landscapes of avandeltas with fair inflow of ground waters;
Landscapes of archipelagos with islands and lagoons.
1. Emerging beach
1st year
without vegetation
2. Ephemeral ecosystems
5 - 7 years
Rich halophyte and
hydrohalophyte vegetation
5. Desert
Stable system
3. Waste lands (or
heaths)
11-19 years
No or very sparse
vegetation
4. Neo-ecosystems
Dozens of years
Semi-desertic sparse
species
Main processes:
Main processes:
Ground water level fall
Deflation
Decrease of salts in soils
Increase of salts in soils
Fig. 4: The model of ecosystem changes on the dry bottom of the Aral Sea
5.4. Objectives of future investigations
Target of future investigations during the post-launch phase of SPOT-4 is to combine classified
SPOT-4 VEGETATION data with the existing model of landcover/landuse dynamics. We plan to
develop procedures to update and replenish information on spatial distribution of ecosystems in each
stadium for the entire Amu-Darya delta and the dry bottom of the Aral Sea utilizing VEGETATION
data. Due to the frequent acquisition of VEGETATION images we will derive time series analysis to
describe the typical vegetation behavior of each ecosystem stadium during the entire vegetation period.
This enables the investigation of ecosystem development on a fairly small time scale which will help to
understand the dynamics during the transitions between the different stadiums.
6. APPROACHES FOR INCORPORATION OF LANDCOVER/LANDUSE CHANGE MODEL
RESULTS IN THE ARAL GIS.
6.1. GIS and database replenishment for future ecosystem modeling
To fully describe the ecological situation within the ecosystems and to evaluate the processes of
ecological changes a large ecological database for the delta has been set up. Main goal was the detailed
description of geo-locational factors (such as soil, salinization of soils, groundwater, etc.) as additional
information source for the modeling of ecological dynamics. The implementation of the results of the
ecosystem modeling into the GIS will provide correct and accessible data about ecological conditions
for both natural and man-made ecosystems. Satellite information from VEGETATION will be
incorporated in the GIS together with the existing remote sensing information to deliver full coverage
data for the entire Amu-Darya Delta. This information will assist end users of the GIS such as
irrigation and civil engineers, natural resources managers, governmental officers from various
departments, scientists, natural protection organizations and especially decision makers to derive
crucial information for their environmental work. The existing information layers in the GIS database
can be seen in Tab. 5.
Chapter
#
Topic
Scale
1
Topography and
bathymetry
1:500000
1:200000
2
Geology
1:2500000
*
3
Tectonics
1:2500000
*
4
Geomorphology
1:1000000
1:200000
*
*
5
Quaternary
1:1000000
*
*
6
Climate
1:2500000
*
7
Ground water
1:1000000
*
8
Surface water
1:1000000
*
*
*
9
Soils
1:1000000
*
*
*
10
Vegetation
1:1000000
1:200000
*
*
11
Animals
1:1000000
*
*
12
Landscapes
1:1000000
1:200000
*
*
*
*
13
Administrative
borders
1: 2500000
1:100000
1:500000
*
*
*
*
14
Population
1:1000000
*
15
Occupation
1:1000000
*
16
Public health
1:1000000
*
17
Water husbandry
1:1000000
*
*
*
18
Irrigation
*
*
19
Transport
1:1000000
20
Desertification
processes
1:1000000
1:200000
*
21
Air pollution
1:2500000
22
Surface water
pollution
Ground water
degradation
Soils degradation
Digital layers
Ecological conditions
Social and economic features
Geographic features
P
Legend:
23
24
I(h)
L
Pt
R
*
*
*
I(l)
S
G
T
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
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*
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*
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*
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*
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*
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*
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*
*
*
*
*
*
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*
*
*
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*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
1:2500000
*
*
1:1000000
1:200000
*
*
*
*
*
*
*
*
1:1000000
1:200000
*
*
*
*
*
*
*
*
25
Vegetation
degradation
25
Aral Sea ecosystem 1:1000000 *
*
*
*
*
*
*
degradation
Digital layers:
P – polygons; L – lines; Pt – points; R – raster (grid)
Space images: I(h) – high and middle resolution (LANDSAT MSS and TM, Resource-O);
I(l) – low resolution AVHRR (NOAA)
Data:
S – statistics; G – graphics; T – text descriptions
Tab. 5: Existing database layers for the Aral GIS
During the pre-launch phase the following information has been incorporated in the GIS as
supplement information for the ecological modeling with VEGETATION data:
1.
2.
3.
4.
Russian “Resource-O1” satellite images of the years 1995, 1996 and 1997 (MSU-SK and MSU-E
sensor).
Multitemporal AVHRR (NOAA) images continuously starting from the year 1996.
Landuse maps with large scale information on collective farms, towns, pastures, etc.
High accuracy relief map for the northern part of Amu-Darya delta ( 1-m isolines).
6.3. Objectives of future investigations during the post-launch phase
The further development of the land and water GIS for the Amu-Darya delta through creation of
new data layers is planned. Special focus will be put on the derivation of new information using
VEGETATION data for the evaluation of the ecosystem dynamics. Current multitemporal satellite
information in synergy with long term investigations will be used to model future land degradation and
ecosystem changes. The expected results will show:
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the character, extent, and processes of man-made desertification in the delta;
Other forms of soil and vegetation community degradation;
Wetland types and their changes over time;
The frequency, extent and deposition pattern for salt/dust storms;
Critical wildlife habitats and their modifications.
7. BIBLIOGRAPHY
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2.
3.
4.
5.
6.
Ptichnikov A.V.: "The Aral sea Problem and Remote Sensing of Desertification in the Aral sea
Region"/Mapping Sciences and Remote Sensing, Vol. 28, No. 4, 1991
Ptichnikov A.V.: "Landscape approach to study desertification processes in the Aral sea area using
space imagery"/Technical meeting to develop methodology of desertification assessment in the
SPEAR/UNEP project. Moscow, 1991, p. 12-20.
Ptichnikov A.V.: "Modern landscapes of the Aral Sea region. World Atlas of desertification"
UNEP, London, 1991, p.85-87.
Dech, S.W. & R. Ressl: “Die Verlandung des Aralsees - Eine Bestandsaufnahme mit
Satellitentechnologie,” Geographische Rundschau, Bd.6, 1993, pp. 345-352.
R. Ressl: “Multitemporal area and volume calculations for the Aral sea using NOAA-AVHRR data
and development of a GIS for the Amu-Darya Delta,” NATO Science Division Affairs
Publications Springer/Verlag, 1996
Ptichnikov A.V.: "Change of environment and landscapes in the Aral sea region as detected from
satellite data", NATO Science Division Affairs Publications, Springer/Verlag, 1996