MONITORING OF CHERNOBYL DISASTER AREA USING MULTITEMPORAL SATELLITE DATA
Lyalko V.I. Sakhatsky A.I., Hodorovsky A.J., Shportjuk Z.M., Sibirtseva O.N.
Center of the Aerospace Research of the Earth, NAS, Ukraine, Kiev,
Marek K.-H., Oppitz S.
Remote Sensing Center, UVE, Germany, Potsdam
ABSTRACT
In order to assess sustainable development of Chernobyl disaster area, it 1s necessary systematic control of environmental state using
multispectral satellites imagery method for operative monitoring of large area with minimum financing and without risk for observers
health. The approach of works includes: * intercalibration multi-temporal Landsat TM and SPOT images; * landscapes classification;
* revealing of regression dependencies between spectral characteristics of vegetation and radioactive pollution level; * modelling of
energy-mass exchange in geosystem on the basis of remote sensing and ground data. It was indicated that the increasing of radioactive
pollution level cause the changing of the spectral response both in visible and in mid-infrared portion of the spectrum. The carried out
environment monitoring allow to observe the regularity of changes of the different landscapes since 1984 (before disaster) until 1995
year. The same approach can be used for assessment of influence of heavy metals, herbicides and others toxicants on environment.
KEY WORDS: Monitoring, Chernobyl disaster, multitemporal data, modelling.
INTRODUCTION
As a result of Chernobyl disaster the large area have been
polluted by different radionuclides and heavy metals. The
radionuclides and others toxicants fell down located in vegetation
or moved throughout the high permeable zones to underground
water and polluted them. The toxicants come to human body by
food chains from vegetation or with underground water intake.
Therefore, it is necessary to carry out control of environmemt in
monitoring mode taking into account that the pollution of the
area 1s stipulated for long-live radionuclides with period of half
decay not less then 30 years. Multispectral satellites high
resolution imagery is the only method for operative monitoring of
vegetation within large area with minimum of financing. The use
of space images data of past years allows to carry out
investigations retrospectively. It is impossible to do using any
other method. The multiband space survey is rapidly improved.
Every year the quantity of countries, which launched satellites,
increase and the apparatus became more perfect with more high
resolution and quantity of spectral channels.
The use of chemical analysis for indication of radionuclides and
other toxicants content leads to significant expenditures of
financing and time interval to take samples and to analyse ones.
So, it is obstacle to do observations operatively.
On the other hand, the transfer of radionuclides from soils to
vegetation depend on many factors. The spectral brightness of
vegetation characterize the direct total soil toxicants influence on
vegetation state - content of chlorophyll in leaves, moisture in
vegetation and so on. The ground truth observations is also
necessary but restrictively within the test sites for determination
of relations between spectral characteristics of vegetation and
content of toxicants in soil. It is well known that the processes
leads to the natural changes of environment is the processes of
energy-mass exchange in geosystems, in fact. Therefore, the
proposed approach for ecological monitoring of Chernobyl
disaster area consist of three principal blocks:
- the estimation of vegetation state using multiband
multitemporal space images;
- the acquisition and processing of ground-truth and satellite
data using GIS technology;
- energy-mass exchange modelling in geosystems.
The results of the investigations will be base for decision
making.
1. OBJECT OF INVESTIGATION
The objectives of the investigation is to set up a monitoring
system of Chernobyl] NPP disaster area using multiband
multitemporal satelitte images. The ChNPP is situated in the
North of Kiev district, Ukraine, approximately 130 km to north-
west of the city of Kiev. It is a landscapes of fluvioglacial and
alluvial plains. The moraine-fluvioglacial deposits form the
upper layer of the relief with altitude of 140-150 im. The south
and west edge of the region is a low moraine-fluviaglacial plain
with altitude 120-130 m, increasing towards the west. Bog
depressions are usual for this region. There are sites of locked
surface outflow and partly they are not drained at all. Alluvial
valley is connected with the Pripjat river. The forest covers
approximately 3596 the area, mainly pines but also mixed with
deciduous trees. The un-drained agriculture land takes about 30%
of the area, and meadows and bogs about 2096. Drained
agriculture fields occupy about 10% of the territory. After the
accident in 1986 year the significant changes are observed within
this area. The fields transform to long-fallow lands. The
agricultural plants are replaced with wild shrubs and grass. The
leaved settlements are covered with wild vegetation. In the same
time there are many new man made objects - roads, damps etc.
The sod sandy loam soils, sod-podzolic soils and peat-march
soils are usual for this area. Concerning the geology structure, the
area is situated on the north-east slope of the Ukrainian shield at
the boundary of Dniprovsko-Donetsk depression within the
limits of the Braginsko-Chernigovskiy jut which separates the
Pripjatskiy depression from the Dniprovsko-Donetsk depression.
The structure of the region is determined by in great number
different oriented fracture zones. They were formed in the Pre-
Cambrium. The crystalline basement of the region is overlaid by
sediments of Mesozoic and Paleogene, Neogene and Quaternary
age. The Quaternary sediments (from Lower Quaternary to
recent sediments) consist of bogs and of glacial, limnic, eolian,
726 International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998
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