Lahar damage assessment using satellite remote sensing : The Mount Pinatubo experience

The catastrophic eruption of Mount Pinatubo on June 15, 1991 resulted in the monumental task of immediate damage assessment and monitoring, and the long-term mitigation measures including resettlement and rehabilitation, by the Philippine Government. However, the lack of accurate and timely information on the highly dynamic boundaries of the mudflow that characterized the desert-like "lahar-scape" of Central Luzon hampered such government plans. Aerial photography and satellite-based imagery acquired in the visible-infrared portions of the electromagnetic spectrum have provided basic information for the preparation of lahar-hazard maps. In addition, synthetic aperture radar (SAR) technology, both airborne and spaceborne, has been used to supplement the visible-infrared data for lahar damage assessment and monitoring. This study likewise examines a proposed model for monitoring lahar movement in relation to infraestructure activities

Problems and solutions of thermal infrared remote sensing for drought-monitoring

China suffers more from droughts every year than from floods, especially in the Huang-Huai-Hai Plain and Sichuan Basin where grain yield is essential to support large local population and the nation's economy as well. However, it has been an unsolved problem to accurately evaluate the degree of drought over the vast area, so precious water resource and mitigation funds can hardly be allocated effectively. Therefore, large area drought monitoring has been a significant part of China's program "Remote Sensing Monitoring and Evaluation System for Severe Natural Disasters". In this system, various models of daily evaporation and soil's thermal inertia have been developed and employed. However, reliable evaluation of drought needs true land surface temperature (LST), or even better, true temperatures of leaf canopy and background soil as inputs for model inversion. Unfortunately, remote sensing (RS) of LST is a very challenging problem at present development stage of technology. On the coming next generation of RS satellites, there will be advanced thermal infrared (TIR) sensors such as MODIS ASTER, or GLI. Tremendous efforts have been devoted to atmosphere correction and temperature emissivity separation (TES) for new LST product algorithms. However, the mechanism of directionality of thermal emission from land surface remains unsolved, thus the targeted accuracy can hardly be achieved. Partly in order to improve China's RS system for drought monitoring, China's Ninth Five-Year Plan for Key-Important Basic Research (1996-2000) decided to have a project investigating the problems in LST RS and looking for solutions. Meanwhile, the BRDF (Bi-directional reflectance distribution function) which we have been working on is very promising to provide possible solutions with needed structural information

Tu oportunidad de sobrevivir : Manual del estudiante

Incluye información detallada y medidas preventivas en caso de incendios, forestales, olas de calor, tornados y tormentas, huracanes, inundaciones, tormentas invernales, terremotos y maremotos, emergencias y fallas tecnológicas, contaminación del ambiente, desastres nucleares. Explica diferencias en los sistemas de alarma utilizados en caso de ataques enemigos y de desastres naturales. Otros aspectos considerados son: los refugios en el hogar, la reacción psicológica ante crisis y desastres, la función de la comunidad y del gobierno en emergencias

Volcano monitoring by short wavelength infrared satellite remote sensing

Data from remote sensing satellites operating in the short wavelength infrared can be used to measure temperatures, integrated across a pixel, of about 150 C and over. This makes it possible to investigate volcanicn phenomena. The gain settings of the Landsat Thematic Mapper sensors are such that to record pixel-integrated temperatures from 150 C to over 1000 C requires the use of several spectral bands. If tje radiant source occupies less than a whole pixel, as is the case for fumaroles or a crusted lava surface with incandescent cracks, then the pixel-integrated temperature is less than the actual surface temperature of the hot areas, and moreover appears lower at longer wavelengths. By deternining pixel-integrated temperature two spectral bands we can estimate both the temperature and size of hot areas which occupy less than a complete pixel. In some cases our observations provide the only available data on yhe state of activity of a particular volcano. The effectiveness of short wavelength infrared satellite remote sensing data for volcano monitoring is currently restricted by several factors: 1) The cost of purchasing data for frequent monitoring 2) The time-lag between acquisition of data and distribution to the user 3) The long repeat time of downward-pointing high resolution satellites such as Landsat 4)The lack of shortwavelength infrared sensors in the 1.5-30 um region on systems other than Landsat TM. In order to cover the temperature range 200-1000 C using a single spectral band near 2 um a sensor would-need to be sensitive to radiance over a range of four orders of magnitude, whereas the present TM band 7 sensor is valid for radiance covering little more than one order of magnitude. In contrast, the same range of temperature could be covered by a single sensor operating in the 10 um single order of magnitude. This could be accomplished by decreasing yhe sensitivity of the existing Landsat TM band 6 sensor by about a factor of 50, without altering is gain. However, a second sensor ata shorter wavelength would still be required in order to extract information on temperature distribution at the sub-pixel scale(AU)