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Satellite Data- Based Natural Hazard Study in Iran
3.6. Monitoring of Volcanoes
High multi-temporal resolution coupled by high spectral resoulotion provided by data acquired by ASTER on board of TERRA satellite has provided a unique opportunity for geoscientists to achieve to a comprehensive understanding of volcanoes characteristics and being able to prevent the resulting disastrous hazard.
Studies made by different specialists around the world now has proven that, these data could effectively be used to access the information required from different phases of volcanoes activities starting from its heating up phase down to evaluation and mapping of affected by regions.
Due to existence of such a potential sources of natural hazards and being fortunate( for the time being at least) not to have eruptions from even active quaternary volcanoes of the country, we are trying to establish a GIS-based databank for potential volcanoes of the country. In this regard, while we are using Landsat images to create a DEM from these volcanoes ( Fig 9) and trough its integration with other sources of data for its respective use in morphological analysis and establishment of a GIS-based databank.
To reach to our goals, we are now trying to monitor and gather information related to;(1) vegetative cover changes,(2) existing hot springs and their temperature changes based on the data gathered trough field measurements, (3) dominant wind directions, (4) existing villages ,(5) reconnaissance of evacuation routes and other parameters involved.
It is hoped that such a databank could be used not only to predict the time of eruption but also to be used for crisis managements and preparation of rehabilitation plan .
3.7. Earthquake Impact Studies
Earthquakes is the most destructive natural hazard with a vast environmental, economic, social , cultural impact which still can not be predicted . Regardless of on-going activities by numerous seismologists around the world, presently main concentration of those involved in this subject, is to prevent the event through different approaches.
One of the basic steps in this regard, is based on mapping of active faults and use the maps prepared to define seismic prone areas and their zonation which itself are used by seismic engineers to calculate the coefficients required for reltec calculations and designing of the structures to reduce the probable casualties and financial impacts. Based on this effective approach, we have used different space taken data, including photos taken by astronauts on board of GEMINI,APPOLO spacecrafts and also those acquired by Landsat series of satellites (both MSS and TM ) to map basement and unknown faults to be added to previously mapped faults and to update the existing information.
Such a information extractedby conventional interpretation technique , was associated with a huge amount of new findings which were presented in the form of Seimic-Faulting Risk Map ( Barzegar et al, 1997 ) . This map itself were later used for production Seismic Risk Map of Iran to be utilized in National Spatial Plan of the country.
In the recent years , after launching of ERS ,Terra and Envisat satellites in to the earth orbit, we are using InSar, ASTER and ASAR data on board of these space platforms and new interpretation techniques developed ( such as Interferometric Analysis) to complete our knowledge and find a better understanding about these features and the mechanism involved.
In addition to these sets of data, very high resolution satellite data taken by IKONOS and to some extent Quickbird can also be used for damage assessments with regards to preparation of large scale damage map of the areas under destruction impacts as well.
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