(back to the Netscape version)
This Landsat Thematic Mapper image (ID # 5021050009504010) was collected on February 9, 1995. The false color display has band 5 displayed in red, band 4 in green, and band 2 in blue.
The image shows the entire volcanic hazard zone associated with Santa María Volcano, extending downslope to the south from the volcano (3770 m elevation)to the sea level. The volcano itself is located at the upper right of the figure, and a transparent eruption cloud (white) which is drifting to the south of the volcano can also be seen. The false color image shows heavily vegetated area in green tones, agricultural areas in red and unvegetated rock as blue. The blue tones highlight the volcano and the areas of hazard associated with consequent sedimentation along the Rio Samalá and other rivers of the aggrading alluvial fan of volcanic sediments south of the volcano all the way to the Pacific Coast.
This image was processed by Paul Kimberly at the Laboratory of Atmospheric Remote Sensing at Michigan Tech, and is a part of an effort to map changing hazards using satellite data.
Santa María, an international decade volcano in Guatemala, presents significant volcanic hazards to its surrounding populations from its activity, which has been continuous since 1922. We have prepared a GIS array for the volcano and its surroundings, which combines volcanic hazard zonations with four layers of economic and population data (population, infrastructure, land use, and standard of living). The goal is to present on a single map, the risks of volcanic activity in terms that the public can better understand. The map, which shows the cost of the volcano to the Guatemalan government, to be between 3.3 and 8.4 million dollars U.S. a year, is developed and shared using an internet world wide web vehicle, which facilitates some complex overlays.
Although volcanic hazard maps are now available at many hazardous volcanoes, volcanic risk maps are very rare and may offer some special advantages in Volcanic Hazard Communications efforts. They can be used to forecast the cost of volcanic activity, which may be helpful in securing budgeting for mitigation efforts. They may be used for planning mitigation expenditures, because sensitivity analysis of uncertainties in hazard zonation or recurrence intervals of various types of activity can be tested against economic and population data for cost effectiveness.
Santa María is located in southwestern Guatemala
14.758 degrees N latitude, 91.548 degrees W longitude
- forecasting the cost of volcanic activity
- planning mitigation expenditures
Nature and Source of Hazard Information
1. What geographic area would be affected in a volcanic event?
2. What type of destructive force would take place in that geographic
area?
3. What are the probabilities of a volcanic event in a given time
period?
Standard of Living (adjusted GDP per capita)
Population Density (# of people/hectare)
Infrastructure (kilometers of higways, electrical distribution and
transmission lines)
Landuse (dollar value/hectare)
SOURCES:
COST OF LIVING WITH SANTA MARIA EXPECTED LOSS DUE TO
(1 year period) VOLCANIC RISK
U.S. DOLLARS (dollars/hectares/year)
ZONE LOW (est) HIGH (est) MINIMUM MAXIMUM
1 146,918 323,221 97.34 214.15
1a 59,915 119,830 96.22 192.43
1b 33,722 67,444 87.90 175.79
2a 13,815 27,630 19.02 38.04
2b 9,357 18,714 7.52 15.04
3 785,076 1,727,167 863.53 1899.76
3 1,649,395 3,628,669 209.17 460.18
4 132,491 519,368 106.63 417.98
4a 492,612 1,931,039 21.75 85.25
TOTAL: 3,323,301 8,363,082
TOTAL ECONOMIC VALUE - By Municipality
(dollars/hectares/year)
El Palmar: $1,632.39/ha/yr
San Andres Villa Seca: $1,887.83/ha/yr
Retalhuleu: $2,067.59/ha/yr
San Felipe: $8,920.21/ha/yr
San Martin Zapotitlan: $9,365.97/ha/yr
Santa Cruz Mulua: $1,071.92/ha/yr
San Sebastian: $11,384.24/ha/yr
Champerico: $890.53/ha/yr
Areas for further analysis
Which hazard zone is most important economically and what does uncertainty in hazard zones contribute to the risk estimate?
Consequently, Zone 3 deserves further study because there is large uncertainty in the expected risk.
Additional Considerations: Inclusion of a .5km buffer zone (fig. 7) around the hazard zone (fig. 6) shows a substantial increase in total value.
Total Hazard Area Hazard Area (fig. 6) (with .5km buffer zone fig. 7) Tot. Value $70,711,540 $102,672,649 Tot. Area 37,174.90 ha 46,220.92 ha Value increase 45% Area increase 24%
Consequently, further study is needed on the exterior boundary
Volcanic Risk can be represented in the following ways;
1. Inclusion of Expected Loss due to Volcanic Risk map (fig. 6) with Volcanic
Hazard maps (fig. 1)
2. Use colors to differentiate amounts of risk.
3. Include in the legend a dollar amount expressed by
"the expected loss due to volcanic risk"
4. Include maps of the principle economic data used in risk assessment (fig. 2-5)
Volcanic Risk maps use data from hazard maps
Volcanic Risk maps incorporate probability of volcanic event
Volcanic Risk maps incorporate economic value and activity
Volcanic Risk maps incorporate vulnerability to destruction
We conclude:
Volcanic Risk maps are a tool to evaluate the real cost of
living near a volcano.
This data can be compared with the cost of monitoring and
assessing hazards.
The data can be used to assess which areas to focus hazard
field work.
The volcanic risk map project has demonstrated a methodology that allows for the calculation of the economic impact of an active volcano in dollar terms. It may be useful for disaster preparedness planning, because the real cost of the volcano can be compared with costs of mitigation and monitoring efforts. The assembled data in the GIS format allows ready determination of areas of greatest risk within volcanic hazard zones.
Financial support for this work has come from the National Science Foundation, the U.S. Geological Survey, Volcano Crisis Assistance Team, and from Michigan Technological University.
Many individuals helped: