OPERATIONAL
SPACE MAPPING AS A TOOL OF THE ARAL SEA
MONITORING AND SURROUNDED TERRITORIES DEGRADATION
V.I.
Kravtsova
Lomonosov Moscow
State University, Faculty of Geography, Moscow, Russia
vik@lakm.geogr.msu.su
The Aral Sea
degradation is one of the strongest nature and ecological catastrophes of XX
century. Regular space
surveys and operative mapping have allowed to watch multiyear and
seasonal changes of the Aral Sea area,
formation of landscapes at a former sea bottom, some specific features, so as
salt storms and wind-induced surges, and their impact to surrounded area. Through
many years Laboratory of Aerospace Methods at Department of Cartography and
Geoinformatics, MSU, conducts the space monitoring of the Aral
Sea and surrounded territories. Multitemporal space images (from
Salut, MKS orbital stations, Resurs-F, Resurs-O, Terra satellites) have been
used for compiling of sea coast line retreat maps for the whole period of sea
degradation. The map, which shows 14 positions of Aral coast line in 1957-2003,
has allowed to account sea area degradation. The Aral Sea area in September 2003 was 19370 km2, that is 29% from its
area in 1961.
Due to
regular observations during a year from Terra and Aqua satellites, images have
shown seasonal changes in sea area; comparison of seasonal area variations with
radioaltimetry measurements (from Topex/Poseidon and Jason satellites)
discovers their good connection.
Accurate mapping and determination of sea area shows some seasonal
regularities: growth of area in spring and the beginning of summer and very
fast decreasing in autumn. Fluctuations of sea area show also the influence of
working regime of dam in former Berg strait to humidity of the Northern-Eastern
bay of the Big Aral Sea. Some specific input of Amudarya River
waters into the Aral Sea was seen at images
1998, 2003, 2004, 2006. Moreover salt storms and wind induced surges have been
fixed at space images in 2003 and mapped. Seasonal dynamics of ecosystems of
former sea bottom and surrounding territories has been investigated by mapping
with multiseasonal imagery. A series of seasonal landscape change maps has
shown that the basic processes of a former sea bottom territory seasonal
dynamics are connected to a regime of moistening and salinization, drying of a
ground and formation and then destruction of salt crusts on the edge of the
narrowed humidified strips. These processes are characterised on a series of
maps, which show the main regularities of former sea bottom functioning.
The work was created by Programme of Leading Scientific Schools,
Grant8306.2006.5