Few
things have fascinated Western society as much as the sudden demise of the
ancient Mayan people almost 600 years before European explorers arrived.
With the help of satellite images, we may be unlocking the mystery--and
finding a cautionary story for our own times. The seventh and eight
centuries were a time of crowning glory for millions of Maya in the Peten
region of northern Guatemala. Yet by 930 C.E. (A.D.), only a few scattered
houses remained, testifying to the greatest disaster in human history.
What is known is that at the time of their
collapse, the Maya had cut down most of their trees. Rain forest soil is
shallow and retains little water without dense vegetation to act as a
reservoir. The water table plunged, the land became untenable, and drought
soon followed. Although the rain forest has since recovered, human
habitation leaves scars that are visible only from high altitudes, where
patterns become more visible. Using such images, GHCC scientists and
colleagues have located Mayan pyramids and other ancient ruins that mark
centers of commerce, where scientists can gauge the rise and fall of a
civilization. From these studies, we hope to understand the pattern of the
Mayan decline and also find clues to sustainable agriculture.
The need to understand what happened to the ancient Maya is especially
urgent since their descendants may repeat history. Much of this area has
been set aside as the Maya Biosphere Reserve, but mankind still finds ways
to encroach. Remote sensing by satellites and aircraft have been combined
with geographic information systems to address issues in Mayan archeology
as well as monitor the effects of increasing deforestation in the area
today. Data from the early 1990s show that the forest-clearing rates in
the buffer zone and some corridors in the Maya Biosphere Reserve's
multiple-use zone were more than twice the regional average reported by
the United Nations for the 1980s. The Peten now is the largest remaining
tropical forest in Central America, and again is experiencing rapid
deforestation in the wake of an invasion of settlers. The successful
adaptive techniques of the indigenous population are being abandoned in
favor of destructive single-crop farming and cattle raising. A
comprehensive forest-monitoring program is being designed for future
studies. As the geographic information systems become operational for the
non-governmental organizations involved, satellite-based monitoring will
become an indispensable tool for updating regional maps, and for
convincing the people that wise land management is their best insurance
for next year's crops.
Information provided by: http://wwwghcc.msfc.nasa.gov