Title: Challenges of Data Integration in the Study of a Complex System: A Case Study of Lake Atitl
1Challenges of Data Integration in the Study of a
Complex SystemA Case Study of Lake Atitlán in
Guatemala
Edwin J. Castellanosa, Maricruz de Mejíaa,b,
Beatriz Lópezb, Nancy Girón,a and Willy Knedela
a Universidad del Valle de Guatemala b
Medical Entomology Research and Training
Unit/Guatemala-CDC
SITE DESCRIPTION
- Lake Atitlán is a very deep lake (340 m) of
volcanic origin located in the highlands of
Guatemala at 1,562 m above sea level. - The lake has no surface outlets underground
fissures and seep holes allow water to filter to
two rivers draining to the Pacific. - Lake sides are steep, due to its geological
origins. The lake lies in a heavy seismic zone. - Hundreds of thousands of Mayan inhabitants
belonging to two linguistic groups have lived
there for centuries. More recently, the crystal
blue lake has attracted thousands of tourists
from around the world. - The lake and its watershed were declared a
National Park in 1955. To date, no conservation
laws are enforced in the area. - The region is considered one of the poorest in
the country with high rates of illiteracy and
public health problems.
Town of Sololá
Town of San Lucas
GENERAL RESEARCH QUESTION
How can we use physical and chemical water
quality parameters as integrative indicators of
the effects of human-induced changes on the
resources of a lake watershed?
METHODS
- Landsat TM images from 1986 and 1996 were used to
examine patterns of land use and land-cover
change for the region. - Special emphasis was placed on differentiating
coffee plantations from natural forests given the
importance of that crop on the land-use dynamics
for the region. Band 6 (thermal) of the images
proved to be crucial in achieving this goal. - A complete GIS system was developed for the area
that included physical and social features. - Water quality parameters were measured in situ at
28 sites around the lake during the dry (April)
and rainy (September) seasons. Each site was
located using a GPS. Samples were brought back
to the lab for more sophisticated microbiology
and chemical analyses. - Relevant socio-economic indicators for the 11
municipalities that surround the lake were
compiled from various sources.
Pumping water to analyze for Giardia
SITE LOCATION
Onion plantations near San Pablo